anyone know chevy trucks

[zlam27]

hey guys, i need a little help diagnosing a problem with one of our trucks (94' chevy silverado).

when you put the truck in drive or reverse and gently push on the gas, it spits and sputters like crazy. it will sit and idle fine and it drives fine once you get goin, but when you are goin slow and on the gas 1/4 of the way or less, it has a terrible time trying to run. driving down the highway at 60 and barely on the throttle it will run fine, but at slower speeds when you are on the gas just enough to maintain speed or speed-up slightly, it runs like crap.

anyone have any ideas? this has been driving me crazy. my thoughts are...
- vacuum leak
- bad throttle pos. sensor
- bad fuel pump (doubful since its only at low speed)

zach

[biggen]

try the fuel filter or air filter if those are good run some sea foam thru it it could be a some what cloged injector hope this helps

[SSracingNY]

check plug wires and distributer cap. when was the last time you did a tune up? Cuz on mine ive had a bad distributer or when it starts to go bad, under a load it runs like crap. or maybe you got a bad batch of fuel

[RytM1]

Zach, check out www.fullsizechevy.com , you may be able to find a few answers there.

[Scott-300ex]

it ain't ignition


and i bet you 100 bucks you got crap in your injectors, run it threw a diagnostic tester and make sure all your SENSORS are working properly, cuz its either your sensors aren't equalling out or your injectors are filled with crap


if its carbed you need a new accelerator pump

[dirtriderex]

Buy a Ford

[Honda4trax250x]

weird....this is exactly what just happened to my jeep yesterday

but its all good, cuz while its down i get to drive my dads 01 gmc sierra:macho

[Volcom300ex]

Originally posted by dirtriderex
Buy a Ford

hes asking for a solution not another problem

[SSracingNY]

Originally posted by Volcom300ex
hes asking for a solution not another problem

:p

[trick250r]

my friend's ford is doing the same thing and its been at the dealer for over 4 weeks now. the dealership is saying it might be the alternator of the battery. we can't figure out why it would be any of those things but.............

hope it helped

[BT&D]

EGR valve. I had this with my 91 it would spit and sputter and half the time stall right out as soon as you touched the gas. I would idle fine and if you mashed on the gas pedal it was fine. It's a real easy fix and a $70 part.

[TCracin440ex]

if it was a bad tps your ses light will be on...you might want to take it to auto zone and have them plug that lil hand held thing into it and see...

[redlineranger]

Originally posted by dirtriderex
Buy a Ford

:(...... that'd be the worst thing he could do

[bulkdriverlp]

wtf are we talking about distributor caps and carburators for?? if the truck is a '94 its fuel injection, just take it in and get it fixed, chances are youll never figure it out on your own, newer vehicles are too complicated now adays.lol

[zlam27]

just replaced the fuel filter and the air filter and it didnt make any difference.

could be a messed up injector...

the check engine light isnt on so could it still be some kind of sensor?

ill look into the EGR valve, that could be the problem. is there any way to get rid of that pollution control stuff?

maybe ill run it in to auto zone and see if they can diagnostic test it for me and give me a better idea of what needs done. hopefully they are smarter that most of the people found at dealerships :rolleyes:

thanks a lot everyone, hopefully i can get this fixed.
zach

[Brandon_Lutz]

I would be willing to bet its the EGR valve. My fathers 95 GMC did the same thing after 250 thousand miles. We had to get a replacement. I forgot how much it cost though.

[NikNacs67]

READ ME!

I had a '91 Sierra (242,000 miles) that did the EXACT same thing. Take your throttle body apart and examine and clean all the springs because that's what the new owner of it did and it turned up bein that a spring had corroded and broke causing it to run like crap. He also had to replace 2 injectors. He also just went ahead and replaced the fuel pump too. Hope this helps.

Btw, I also just got a new '94 Silverado:blah: .

[Got nads?]

I am willing to bet that if it is not the fuel filter, then you fuel pump is on the way out. You could always put it on a diagnostic computer to find the source of your dilemma. It will probably end up being cheaper to do this rather then just swapping out parts.

[bigfoot300ex]

Originally posted by Volcom300ex
hes asking for a solution not another problem
exactly what i was about to say:D

[user101]

EGR valve. its proably around $50-$80 bucks

[hemi operator]

If it's a '94 then it a simple TBI motor. There's really not too many complicated parts there. A vaccuum leak is unlikely because there really aren't many vac. lines on that motor, and most of them are hard plastic, not rubber. I suppose you could have a crack but it's pretty tough stuff. When you pull the Throttle Body off the intake (3 bolts IIRC) there's a gasket under there, which I suppose may be leaking. Really doesn't sound like a throttle position sensor problem. Don't know, but there really isn't much there to go wrong.

[Rich250RRacer]

All the TBI motors are known to have problems with the throttle body gasket sucking in. You can usually see it if you open the throttle and look down inside. Check the PCV port on the front of the throttle body, it usually plugs solid with carbon. Another spot that carbons up on these TBI motors is the idle air control. It can be removed and cleaned also.

[represent618]

FUEL PRESSURE REGULATOR!!! Take off the top plate holding the injectors down, flip it over, take off the 4 torx screws holding the bowl on, look to see if the spring is corroded or broke, and if the diaphram is rotten, thus making you lose fuel pressure.

[zlam27]

just changed plugs, wires, distributor and rotor and it didnt affect the problem (it needed done anyway).

where exactly is the EGR valve? ill have to check that other stuff.

zach

[Rdhanded2]

Usually, if it is the egr valve, it will throw a code into the computer. IS the check engine light on? If it is, definately take it to Auto Zone for a free test. They suck, but they can point you in the right direction.