Gas Guage moving up and down?

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Gas Guage moving up and down?

Post by fallvitals »

Im sure you all know me by now, lol... well. I jsut got my 03 (used, of course) CC a few weeks ago. I have notived while driving the gas guage will fluctuate a little over a course of like 5 minutes. But no big deal, I figured it was just changing temperatures, or sloshing gas.

Well, i got home tonight. Put it in park and my gas guage started dancing big time. heres a video,,,

http://www.youtube.com/watch?v=cGhmG5Yy1Vo

I had the defrost on, but apperently the switch was too close to the cold side and I heard the compressor kick on. so i turned the air completely off around 20 seconds into the video, and it stopped bouncing around as much, as you can see.

*Disclaimer, I did search this. It seems the guage is an issue on these trucks, but it seems what mine is doing is different from all the other issues I saw*

I have only had the truck a few weeks. Only filled it up twice, never had an issue with the guage showing a level that wasnt correct, just fluctuting a minor ammount, till this while I was in PARK.

Any idea? this really has me confused... I hope its nothing.. but i figured this would be the best place to start
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Post by F9K9 »

That is not anything to worry about IMO. They really get crazy at 1/4 and below. Try to keep it above 1/2 tank to assist in fuel pump cooling.
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Post by HenryJ »

A couple things to save up for...NOW.

First , how many miles on your truck? If you are closing in on 120k miles then I am pretty sure you have a couple things that need attention.

The wiggling of the fuel gauge could indicate a poor connection at the fingers of the fuel level sender.
HenryJ wrote:Here is a good example -

Image

This one is from a 2000 fullsize with 99,000 miles. Ours is similar , and this one will show the problems. This one was erratic, and sometimes it did not work at all. Eventually it quit all together.
Here is a close-up-

Image

At the top you can see the float rod. It serves as the pivot point and with time wears. This lets the assembly get loose. Below that you can see the two contacts with their tiny fingers. These ride against the printed circuit board. The tips eventually wear out and break off, or the printed contacts on the board wear off.
Another thing to note here is that the plastic starts out white. Additives and contaminants stain it brown. This coating does not help promote good contact.
Now you can see where the problems lie. Another thing to bring up here is the use of additives that coat the components. This is done to prevent the adhesion of deposits. The problem is that while insulating the formation of deposits it may also insulate the contacts preventing good contact as well?
Quite some time ago I read an article about a brand of fuel that uses an additive that coats to prevent the formation of deposits. GM was in the process of investigating if there was a relationship between this and the sticking poppets plaguing the early SFI engines. I never did read or hear more. They solved it by upgrading the spider and therefore eliminating the problem area.
Personally I think there may still be a link to the fuel sender problems. Perhaps the coating traps debris creating an abrasive surface leading to premature wear? Or the coatings interfere with proper contact? I do not have THE answer. I do avoid some brands of fuel and additives though. superstitious? Maybe?
If you haven't been diligent about maintaining the fuel on the upper half of the tank and adding maintenance doses of cleaner, you are probably going to need a fuel pump module soon.
Running some tests would also confirm that the fuel pump is probably not in much better shape : Fuel System Diagnosis , Testing fuel pump
Do some reading about fuel pumps and you will find there is a difference. Get an OEM AC Delco fuel pump assembly. Don't waste time and money going cheap. The aftermarket pumps are junk and usually fail within a year or less.

Next issue.

Your alternator. Reducing the load, by turning off the AC , improved the voltage and steadied the weak connection at the fuel pump sender. The alternator brushes may be getting worn and not producing enough at lower rpm to maintain the system. The battery too could be suspect. If it is the original, you need to replace it as it has outlived its normal service life. Once you have a good battery onboard, look to a replacement alternator. I would suggest reading the "bigger alternator" thread. Long , but helpful. In the end my recommendation is a trip to the salvageyard for an AD244 based alternator. That is the best $50 I ever spent.
Now you might be saying, "I don't need more power." , Fine. The AD244 comes with bigger better bearings, heavier brushes and is all around a better alternator hands down. The stock alternator is mostly done by 100k depending upon how it lived its life.

Summary: Save up some money, you are going to need it soon. Gather up $500 and set it aside. I would buy a junk yard alternator and new belt right now and make that swap first. You may find a tensioner pulley needing replaced during this swap. This swap could get up around $200 by the time things are fixed right.
Then wait for the pump to go and have the $300 waiting to pick up a new module. Rockauto.com might be a good choice, but price it locally too.

Good luck. Be sure you treat your new parts better than the previous owners and they will live a long happy life.

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Post by fallvitals »

wow.. thats a lot of doom and gloom :!:


my truck has 55K on it.

first let me ask.. the thread you linked me to on testing the fuel pump. It says to use a fuel preasure gauge. Doesnt that screw in some where under the hood? I had an ignition coil die on me once, and I recall my dads buddy useing a fuel preasure guage somewhere under the hood? From the way it sounds it seems like an easy test to find out if the fuel pump is infact having issues.


As for the alternator, yeah. they seem to suck on the s-10, my 97 s-10's died around 70K. Got an advance auto lifetime warrenty one. Then it was a POS, till it died (shoulda taken it back but my dumbass lost the recipt so warrenty=fail!). So I bought a new one a few months ago. I would have kept the reciept but apperantly they are different alternators on my current s-10 and my 97... so i traded in the truck and kept the receipt in the owners manual.

The serpantine belt actually looks good.


and what do you mean keeping fuel in the upper half of the tank? just topping it off at half tank? and what kinda of cleaner are you in referance too? I did some searching, and saw lots of folks here recommend mixing 4 oz of Marvel Mystery Oil in with 10 gallons of gas. Some even said it helped their gauge issues?



Im gonna treat this right now as googling a medical symptom... its gonna say your gonna die. Mine isnt doing the from E to F junk liek is so wide spread, just bouncing some in park, and it did it once so far. Just a little fluctuation while driving, but I wouldnt say it nothign any car wouldn't do. But im definantly gonna test the fuel preasure system anyways. Always nice to have a new tool :P And might as well while I still have about 16 days of that 30 day warrenty remaining.
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Post by HenryJ »

My alternators brushes were half gone at 45k miles.

Fuel is the lubricant and coolant for the fuel pump. Running on the top half keeps it cool and wet. This prolongs the life.

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Post by fallvitals »

alrighty, last question, "maintenance doses of cleaner". What exactly is that?
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Post by HenryJ »

Injector cleaner added at least every other oil change. Not the stuff that coats. A simple inexpensive cleaner will work just fine.
You are trying to prevent those brown deposits from forming.

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Post by fallvitals »

So stuff like Marvel Mystery Oil I found in the search isnt a good idea?
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Post by HenryJ »

I haven't tried it. I will have to leave this to someone who has.

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Post by fallvitals »

HenryJ wrote:I haven't tried it. I will have to leave this to someone who has.
Aight. From what I read a few folks here used it and had good results, some even said it freed up their stuck gauges, but they were never right. I think some guys even said they got more MPG. but im sure thats an odd occurance.

I know I tried STP fuel injector cleaner once in my old S-10. And for some reason my MPG went to chit. I went from like 18-19 city to 15-16. Maybe just coincidence, but after about 4 tanks it went away.... kinda leary of that stuff now...
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Post by fallvitals »

okay... wanna bring it up again...


My 03 crew cab, was bought from a dealer, today is like day 15 since I got it, and it has a "30 day warranty". Only like 40% labor and 20% parts discount. I called the car dealer I bought it from, no answer or returned call, I figure he was off today, ill call tommorow if he doesnt by noon.


Say their service department says I need a new pump, About how much would the parts and labor run?

I also wanna ask him:

#1 If i take it there, they find out the problem and I dont want it worked on, is there a fee? (shouldnt be with their warranty, I say)

#2 Can I get the parts needed with the 20% "discount" and install it myslef?

any thing else I should aks, bring up, or know, ??? I sure dont want to pay anything in labor, even with a discount, unless its something I can't do. But fuel pump, I definantly can.

Which it all sucks ass... why couldnt it have been doing this while test driving, they would have fixed it then :twisted:
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Post by F9K9 »

Only thing that I might add is don't skimp on the pump. AC Delco or some member's claim that Delphi is also OEM. I dunno that for a fact but, I would take them at their word. I saw another brand installed on a BlaZeR2 just before a meet in Hot Springs, AK that went bottom up on the trail. It had less than 1k on the rig. The alternator was weak on the 94-98 models, for sure. I had one go out at under 50K. My 97 ZR2's fuel gauge died at around 40K and I just used the trip odometer.

For injector cleaners, there is a master ASE tech (that writes a lot of the ASE tests) on another forum that recommends Techron. I tried it but, have had better results with Sea Foam. HTH
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Post by fallvitals »

Hm, from every thign I read i think the fuel pump is fine, its jsut the,,, crpa. . sender unit? or whatever, level unit (its late, lol) that goes bad,, but its all one part :x

I always reset my trip odometer,, but it will annoy the piss out of me if I have to use a broken fuel gauge. on gmpartsdirect.com the fuel pump is $290. so, i guess that will give me an idea vs whatever the dealer says.

Also,, is there anything else you should change while your doing that (if this is infact what i am gonna ahve to do?) I think i read somewhere some wireharness should be replaced too?
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Post by HenryJ »

The sender condition may be an indicator of the fuel pump condition. Testing the fuel pump will tell the tale.

No wiring should need replaced unless damaged.

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Post by fallvitals »

alright, called the dealer, couldnt get a hold of my sales person. apperantly he was off yesterdy and today, or doesnt car once a sale is made.


but, they gave me an apointment for monday at 1pm. The guy said it sounds like the cluster panel in the dash. That those models have a problem with em. my warranty is, the dealer pays 40% labor, and 20% parts. I told them I hope you all are right and its the cluster panel, cause I hope its not what im tihnking it might be. lol.

I asked if there would be a fee it look at it, and i honestly forgot what he said, i was writing something down as I as listening (I cant multi task), but i think it was a 'we will see' thing. And before they start, im gonna ask what kinda of policy do they have if replacing those parts dont fix the problem. Cause im not paying to change out parts.


And if by chance it is the cluster panel, is that somehting I should let the dealer fix, or can I do it? im assuming its a drop in thing. And when i had part of the dash out to install my radio, the cluster panel looked like it was only held in with a few screws, if its a drop in replacment part, seems like an easy drop in fix?


edit - hell, on gmpartsdirect.com a instrument cluster is just $10 less then a fuel pump! If that is infact what they think it is,,, I would be better off calling around salvage yards first wouldnt I? (all before my 30 days is up)

Im looking on ebay, looks like i can get a used one on there for like $50. but, i would have to have to milage reprogramed and junk wouldnt I?
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Post by HenryJ »

fallvitals wrote:...The guy said it sounds like the cluster panel in the dash. That those models have a problem with em...
If it is the instrument cluster it will be the first that I can recall. The fullsize late models had some speedometer issues, but that is totally different. All the TSBs for the s-series relate to the sender. There is a procedure to "numb" the action, but that did not solve the problems. That will require a TechII and dealer access to the proper software. As I understand it that TSB has been superseded and no longer performed.

I wish you luck, but I would say that they are going to milk you chasing geese. An inspection of the fuel pump assembly will tell the tale.
Personally I would not hesitate to plan on that being the answer to the problem. That comes from dealing with the s-series line personally for over eighteen years now, and the second gen for nine of that. Add to that watching over 500 case studies here. I would do all the fuel system tests to see if they indicate any issues to confirm the need for replacement.


Your dime. No way can a long distance diagnosis be "THE" answer. Use your best judgement and do what makes sense to you.

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Post by fallvitals »

yeah your probably right, I was a little 'excited' at first cause I think it would be a much cheaper part :roll:

Question, when mine acts erratic, its ony in PARK or NEUTRAL. Any idea why, and not all the time?


Question about fuel pump removal. I found this thread: http://www.s-10crewcab.com/phpBB2/viewt ... =fuel+pump

Guy showed how to take off te bed, and access the fuel pump through the gap between the frame and cab..... Looks VERY tight there,, can you really do that? Maybe im doibting it,, but i looked at my 03 betwwen the bed and frame rail, and i dont see how I could possibly get the pump out between the two.

And I dont see any reason why I would ahve to remove the drive shaft liek that fellow did to remove the gas tank if I dropped it. Looks liek in my 03 it comes straight down. Do you know by chance if they changed that design? or any insight there?


Anyways, when I take it, ill definantly make it known that I have done some research on this issue, and everythign I have read points to the fuel level sender. I am curious what their cost for the pump (with 20% off) is vs gmparts direct :roll:


thanks for the help, seriously :)
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Post by HenryJ »

The issue being in park may be related to wiring or a ground in the column? I really don't know. If it operates normally except when in park, I think I would find something else to worry about and live with it.

Pulling the bed is not the way I would change the fuel pump module.

Removing the driveshaft makes it easier to drop the tank straps. I would do that.

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Post by fallvitals »

HenryJ wrote:The issue being in park may be related to wiring or a ground in the column? I really don't know. If it operates normally except when in park, I think I would find something else to worry about and live with it.

Pulling the bed is not the way I would change the fuel pump module.

Removing the driveshaft makes it easier to drop the tank straps. I would do that.
I totally agree, but the thing is when its bouncing around (its always withen 1/4 tank of where it should be), when you drop it from park to any drive gear (it also bounces in neutral) the gauge stays at where ever the needle was when I put it inot gear. When driving a while it acts like it wants to move up as gas is used, but i really havent driven long enough at once to verify that. but pretty much each time i get in, the needle is at a different setting then it should be when driving. but in the ball park of where it should.

I just filled up 11.5 gallons and the needle seemed to hang around the middle of tank for too long.

Im not sure... wont hurt to take it there and atleast let em check it out I guess.



as for pump removal looking under mine today, i really dont see why the driveshaft would need to be removed, even the bolts are on the outside of the drive shaft. Im not sure, I really think they might have made a change in the CC's cause i read lots of chatter about removing the transmission pan being hard cause oft eh cross member, when on mine, i see no issue with it. :?: but either way, i agree, dropping the tank, rather then removing the bed looks better.
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Post by HenryJ »

fallvitals wrote:... i really dont see why the driveshaft would need to be removed, even the bolts are on the outside of the drive shaft.
Do the job and you will see. It can be done with the shaft in place, but it is much easier without it.
...i read lots of chatter about removing the transmission pan being hard cause oft eh cross member, when on mine, i see no issue with it.
Again, try it. It is a Chinese puzzle. It can be done easily, but requires finesse to prevent breaking the fragile plastic connectors on the solenoids.
There is no way to "see" this stuff. Do it and you will know. Trust the knowledge base here. We have all been at this a very long time.

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Post by fallvitals »

I guess, it appears to be one of those, harder-then-it-seems, jobs then, lol.


But, now I have yet another question.. different subject, but im thinking could be related to a bad fuel pump....

Im thinking I made a mistake buying this truck.

again, 03 crew cab, auto, 4.3, 55k miles.

Going back to the girlfriend's house today, i was going up this little incline on a residential street, I was going a little faster then i normally do (i drive very easy ow a days), I was about all the way up this slight incline, around 15mph, about the 1st-2nd gear shift point. I hit a pot hole and felt/ heard something not right, and I watched my rpm gauge go from 2100mpg to 1400rpm and the transmission felt liek i suddenly dropped it into neutral, for about 1.5 seconds, then full power back like normal. :?: This happened as i hit a pot hole, so i thought maybe my foot came off the gas.

Curious about this, on the way home tonight I got on a steep hill, stopped, and started going, around 14mph, about 2300 rpm up this hill and it did it again. very same thing no pot holes here. So i stopped, took off again. nothing. Again, took off hard this time, nothing. Went on up the hill, i think I may have been in second this time (still below 20mph), not paying attention since this portion was not nearly as steep and I was looking for somewhere to turn around and it did it again. So, when this incident happens, it seems to be around the 1st to 2nd shift point (but i dont think its during the shift), theres a drop in rpm, but the gas pedal hasnt moved (makes me think, fuel filter/fuel pump now) its like i just took my foot off the pedal then got back on it.

My first thought was its the transmission! Great! :twisted: But started thinking, its only on hills, so wouldnt really make since for it to only do it there. again when it happens, it is as if im taking my foot off the gas. The rpms drop, engine doesnt rev, so it cant ebt eh tranny dropping into neutral?

Didnt want to start another thread, but, im bad at explaining, its late, i wish i didnt have to ask this, lol. but I think it sounds like a fuel filter/fuel pump issue? (which it never did this before the gas gauge effed up, but i have only had it 16 days, and I really havent driven much since the fuel gauge startedacting up saturday night. so im thinking they might be related..?)

I actually bought a new fuel filter a few days ago, didnt install it yet, im gonna do that, then go to advance auto or harbor freight and get a fuel pressure gauge tester and test the fuel pump.

Liek i said, im starting to think this truck was a mistake.. I hate to saw cause i was starting to really like it... but its mine now... for better or worst :?


edit- im not a huge fan of hardbor frieght sutff, i buy cheap tools there, but they have this gauge, dont se how they can screw it up, http://www.harborfreight.com/cpi/ctaf/d ... mber=92699 it should work just fine?
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Post by HenryJ »

Check all the basics first. Cap rotor, plugs, filters. Heed the warnings about the distributor.

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Post by fallvitals »

going to change the fuel filter now. I will take those other things into mind.

on the distributer. I did some searching, and what im see thats bad is they can potentially crack, which is the issue right?

From what i read its cause of the thread lock build up in the screw holes, and when you screw them back in it bulgues out the plastic, breaking it? and I should clean those holes up the best I can first?

Sorry to be so dim witted about it, i just wana make sure I have it right first before messing with it due to the warnings..
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Post by HenryJ »

yes.

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Post by fallvitals »

gotcha. I just finished replacing the fuel filter... I never knew doing such an easy task could be so hard. #1 smart place for it. #2 couldnt get that stupid plastic nipple thing to depress on the filter. #3 wouldnt get the plastic holder off. Had to take the whole filter off, by that time there was no gas left in the lines :roll: take some WD40 to it, and finally freed it. Now im gonna go drive up that same hill, hopefully with little/no traffic hindering me, then go to harbor freight and get that fuel preasure gauge. hopefully they have it....
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Post by fallvitals »

Little update, I took the truck back up on the hill i took it last night were it acted up. Tried to replicate exactly what i did. Not no issues at all. Drove on a lot of steep hills at low spped, it didnt happen. I even decided to go up to the graveyard (im in WV, very hilly) and it didn't happen there either.

So, im hoping thats it, but im not hoping holding my breath.

Also, I got a fuel preassure gauge with a few attachments (no bleeder valve/line though..) $9.99, oil pump handy for the upcoming diff/transfer case fluid change $7, tire gauge $3, and valve caps, $1. $21 for all that, not bad :)
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Post by fallvitals »

antoher update, I just tested the fuel preassures... heres how it went.
Inspect the fuel system for damage or external leaks before proceeding with this diagnostic.

Is the fuel pressure within 60-66 psi?

Monitor the fuel pressure gauge for 1 minute.

Does the fuel pressure decrease more than 5 psi? This step tests for an internal fuel leak. If the fuel pressure decreases during this test, an internal loss of pressure is indicated.
The needle stayed at 60 PSI for a few minutes, never fell. Good.
1. Relieve the fuel pressure to 10 psi.
2. Monitor the fuel pressure gauge for 5 minutes.

Does the fuel pressure decrease more than 2 psi? (fuel pump or injectors)
This was a bit tricky without a bleeder hose attachment (im gonna see if I cant just buy the fitting for one online). I unscrewed the connector till I lowered it to 10PSI. I left it alone for 2 minutes, went to check on it, and it rose to 12.5 psi o_0 ??? but stayed at 12.5 psi for 5 minutes, the total test from when i lowered it to 10spi to the end was 7 minutes. But the gauge never fell.

1. Turn ON the ignition, with the engine OFF.
2. Monitor the fuel pressure gauge.
3. Start the engine.

Does the fuel pressure decrease 3-10 psi when the engine is started? This step tests the fuel pressure regulator. The fuel pressure regulator is controlled by engine vacuum. With engine vacuum applied, the pressure should decrease by the specified value.
The Needle stayed at 55 psi, while idling, I reved the engine manually it rose to 60pis, dropped to 50, then came back up to idle at 55psi.

So it looks like it all good (right?). So.. fuel pump is still good...


So my fuel gauge problem has to be the fuel level sender, or the cluster... either way,, I think ill leave it be,, but I am still gonna go to the dealer monday and let them look at it,, why not...
fallvitals
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Post by fallvitals »

I wish I could let this thread die!

I went to the dealer.... I waited and waited, got ticked, and left.



I was browsing ebay today and found this, and other like products.

http://cgi.ebay.com/ebaymotors/GM-FUEL- ... 958wt_1197

Its for a Sonama, which is probably the same one in my truck.

But, I was under the impression from reading ehre, and other places. you couldnt just replace the Fuel Level Sender? If that was the right one, I could get it for less then $30, its brand new. Im assuming you reuse the float..? But, My fuel pump is good, i tested it... Looks like its only held on by those two clips on the bottom of it...

Or am I missing something...? Seems like a easy fix, and not having to replace the entire pump like I thought? :?:
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1337vending
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Post by 1337vending »

fallvitals wrote:
Going back to the girlfriend's house today, i was going up this little incline on a residential street, I was going a little faster then i normally do (i drive very easy ow a days), I was about all the way up this slight incline, around 15mph, about the 1st-2nd gear shift point. I hit a pot hole and felt/ heard something not right, and I watched my rpm gauge go from 2100mpg to 1400rpm and the transmission felt liek i suddenly dropped it into neutral, for about 1.5 seconds, then full power back like normal. :?: This happened as i hit a pot hole, so i thought maybe my foot came off the gas.

Curious about this, on the way home tonight I got on a steep hill, stopped, and started going, around 14mph, about 2300 rpm up this hill and it did it again. very same thing no pot holes here. So i stopped, took off again. nothing. Again, took off hard this time, nothing. Went on up the hill, i think I may have been in second this time (still below 20mph), not paying attention since this portion was not nearly as steep and I was looking for somewhere to turn around and it did it again. So, when this incident happens, it seems to be around the 1st to 2nd shift point (but i dont think its during the shift), theres a drop in rpm, but the gas pedal hasnt moved (makes me think, fuel filter/fuel pump now) its like i just took my foot off the pedal then got back on it.

My first thought was its the transmission! Great! :twisted: But started thinking, its only on hills, so wouldnt really make since for it to only do it there. again when it happens, it is as if im taking my foot off the gas. The rpms drop, engine doesnt rev, so it cant ebt eh tranny dropping into neutral?
I've also noticed this 2-1-2 shift problem on my truck, ever since it's been new. It occurs when the truck is decelerating while at part throttle at 16mph. This generally happens on a hill, or going around a corner at slow speeds. I'm pretty sure it's a bug in the transmission programming, but I haven't fired up EFI live to check the transmission tables.

Also, I watched the video of your fuel gauge, and it looks just like mine has ever since I bought the truck. In gear, I think the computer applies some smoothing to the fuel sender output (so you don't get wild fluctuations on hills, etc.) Once you put it in park/neutral it doesn't do any correcting. If your truck is pointed downhill at a stop and you put the truck in neutral, you should see the fuel gauge go down... Once again, I've noticed this since the truck had as few as 20k miles on it back in 04-05.

Anyways, it doesn't sound like your truck is particularly defective or broken. I would keep up on the preventative maint. like fuel filters, oil changes and the like. Personally, I like to use a fluid pump to suck ATF out of the dipstick tube every 20k miles and replace it with new fluid. This way the it gets a partial change every 20k.

Don't sell the crew cab!
[size=75]2003 Indigo Blue Crew Cab - EFILive custom tune, K&N filter, Magnaflow Exhaust, Rear sway bar, ZR5 wheels w/ BFG 30x9.5x15 AllTerrains

Future mods:
Single 6.5" Bazooka behind the backseat[/size]
fallvitals
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Post by fallvitals »

thats good info too.

ou got me thinking about that sucking some of the ATF out every 20 (maybe do it like 10K) But still need filter change every so often... Tranny place that did my flush/filter change said every 35K.

But since I had that flush, I have yet to have that issue with the tranny acting like its in neutral. I havent been holding my breath about it, but it has been over a month since I had it flushed and it hasnt done it. :D

"I've also noticed this 2-1-2 shift problem on my truck, ever since it's been new. It occurs when the truck is decelerating while at part throttle at 16mph. This generally happens on a hill, or going around a corner at slow speeds. I'm pretty sure it's a bug in the transmission programming, but I haven't fired up EFI live to check the transmission tables. "

Thats a dead on description of what happens. Makes me feel better knowing its probably nothing and other people know what im talking about. Still odd it hasnt done it since I had it flushed... even went on some steep hills stopping and going trying to get it to do it, and couldnt. but before when i tried i got it to do it maybe once every 3 tries.

Not selling the crew cab! I have only had it, less then 3 months. I have decided im gonna lift it. Hopefully starting by the end of the month.
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Post by killian96ss »

When I had my CC my fuel gauge was always innaccurate. :x Even after the dealership reaplaced the sender and reflashed the PCM with an updated calibration the problem was still the same. :roll: I really doubt replacing the sender is going to fix the problem. Amost all late model S10's have faulty fuel gauge readings and there is no real cure for the problem. Adding Marvel Mystery oil to the gas seems to be the best fix since it cleans and lubricates the sender contacts. :wink: When I bought my ZR2 I started adding MMO to the oil every fill up and so far my gauge has been very accurate. :D

Steve