Tuck acts like its running out of fuel...

[Wrenchthrower]

So I literally just bought a not very brand new 1988 GMC sierra sl..it sure is a beater, but I needed a truck, and this one was $800 and did fine on the test drive when I went and looked at it.

Well, I just drove it home, and on the way back it started acting like it was running out of gas, fuel was low, and the gauge floats all over the place, so I figured that's what it was...tried to give it throttle, and it would sputter and backfire and try to die, had to down shift to keep moving cause I literally couldn't stay up to speed to maintain 3rd, 4th, and 5th.

Engine light came on, so I figured..alright, time to pull over, it doesn't wanna go anymore (was going up hill) so I pulled over, turned it off...got mad, yelled at my brother on the phone for talking me into buying his friends pos truck, then decided to crank back up, see what happens....

It ran.....and ran normal...for another couple miles anyhow, and did the same thing.

I slung it in neutral, off/on again and it drove fine again?

As soon as it starts doing that, and I turn the truck off and on, the problem goes away immediately....

Fuel pumps turning on, I can hear it. I'm confused as to what this could be since it goes away simply by Turing the truck off and on again.

Anyone ever have this issue before? Could it be the regulator or something?

Help?!?!

Sorry for the essay, guys.

 

[oldfoggie]

replace the fuel filter, on my 98 I think it was on the frame under the drivers door

 

[Wrenchthrower]

I'm gonna replace that anyway, but I'm thinking it might be the egr valve. I remembered I had a mustang that used to do the same thing, and that ended up being the problem. I just need to get this truck running until I can afford something else. This things got just a little over 200k miles and I don't think it's ever had any work done on it. Should be fun....

 

[98trck]

here is another possibly, happened to a friends Camaro
a piece of trash in the gas tank (it looked like a tree leaf)
when the engine runs the leaf would cover the fuel pickup, starving the engine of fuel
shut it off the leaf falls away, engine runs fine, again till it happens again
PETE

 

[Wrenchthrower]

So, I changed the egr valve, and fuel filter, and the truck still bogs down and starts to backfire when i give it fuel. Again, fuel pump is turning on when I turn the key over, so I don't know wtf the problem could be, I'm not great at diagnosis.

 

[Bill325]

My previous truck was a 1989 Chevy with the 350 engine, and throttle body fuel injection. I paid $900 for it. It too had about 200,000 miles showing on the odometer. Driving it home the first day, it started running very rough , and I noticed it showed zero oil pressure at idle. I added two bottles of Chevron Techron fuel system cleaner to the gas tank, and started using 20w-50 weight oil. Both the rough running and the low oil pressure problems cleared up almost immediately, and I ran the truck another three years without problems. In my opinion, those were the last of the good quality GM pickups . My current truck is a year 2000 GMC Sierra , which is not nearly as good a truck, and which has cost me a small fortune in repair bills.

 

[CJH1981]

That sounds like the modern day "Reduced Engine Power" issue. My 03 does that, but it's all digital and complicated now. The usual suspects for that issue are the o2 sensors, APS, and Throttle assembly.

 

[oldfoggie]

I think the biggest problem is the increasing electronics used and the sensors don't stand up in all the different weather conditions, my 90 GMC Sierra and 98 Chevy Silverado were the best trucks I have owned, same thing with cars,now they are cheaper built, poor quality and way over priced for what they are.

 

[Wrenchthrower]

So I've been pondering and pondering this fuckin basket case of a vehicle, and now I'm thinking....this could possibly be a crank sensor issue..it makes sense. Trying to stall at high, or low engine speeds by confusing the computer on how to work the injectors. I may try throwing one on, but in my limited experience of working on vehicles, symptoms are all pretty generic for everything..

 

[Wrenchthrower]

OK, so...I retract that statement, as i dont believe this truk has a crank sensor....however, I ran the shade tree diagnostics on it, and after giving me the code 12 (1 flash-pause then 2 quick flashes) it does 4 quick flashes...but I don't know what that translates too, and can't find ahit about it online. Got any guesses?