95 Tahoe problem

Problem with stumbling/bucking/loading up when taking off with very light throttle. Mostly after the engine warms up a minute. No codes recorded per the scanner, "check engine" lite does not come on. Heavy acceleration is ok. Also likes to die when slowing down to take a corner as you turn the wheel.

Category:

Autos & Vehicles

Tags:

• 1995
• chevy
• tahoe
• problem

[Needmorehorsepower]

acts like a tps on the trottle body i dought its a cat or fuel pump and both of those would act in reverse if they where bad good off idle accel and flooring it would show stumbes and not run rite on high rpm.The tsp swithc has to be ohm'ed out to see if it is ok and advanced auto or auto zone should be able to hook up and tell you what the temp sensor is saying for temp,and it could very well be the idle air control i have seen them do some weird stuff but that will most likely throw a code

[fortyfiveplayer]

@Needmorehorsepower Thanks! I'm going to take the TBI off it tomorrow and clean it, and test the TPS too. I have to replace the hi side AC shrader valve o rings anyway, so might as well do it all and get it done with...

[towrecker]

if you floor it , all is good right ? if so first thought is this , throttle position sensor , for fun try this , unhook the o2 sensor after the cat , and set off the check engine light , this will put it in open loop (the computer that is ) and see if it runs right , it might seem weak , but see if that stops it , that will eliminate the computer as the issue ,watch the video I upload tonight on how to clear the code , without a scan tool too lol

[fortyfiveplayer]

@towrecker Oh yeah- if you step on it, it puts you back in the seat, smooth as can be- But just try to "float" the engine, and it all turns to sh*t. See the other video I put up with that mystery spacer- not sure if that is part of it, either.

[tss212]

unhooking rear o2 will not put in open loop. and being pre obd2 it will not have a rear o2 sensor

[tss212]

Catalytic Converter, Fuel Filter, and check fuel pressure.

[towrecker]

it could be the coolant sensor too ,the computer thinks the engine is still cold , and running it very rich

[craig1974]

Weak fuel pressure?

[sandmanxo]

I'd start by cleaning the throttle body if you haven't already, then change out the idle air control valve. Beyond that, I'd guess O2 sensors since you said it's running rich. I don't know what type of ignition it uses, but it could also be a plug not firing.

As long as the check engine light isn't coming on, it's not going to throw a code. If you drive it around for a while while it's running like crap, it might eventually throw a code, which may or may not be helpful.

[uxwbill]

Hmmm...couple of thoughts...is the engine coolant temperature sensor good? (This is seldom courteous enough to set a code if's returning absurd values and the dash gauge usually reports data from a dedicated sending unit.) Got any cracked, plugged, or generally bad vacuum lines? The throttle body could be dirty--sometimes that happens and causes very odd behavior.

I'll ask the Keykeeper to watch and give his thoughts.

Looks like beautiful country around those parts!