help my chevy s-10 is sick

[perry 82]

my s-10 has been running rich and it spits-sputters and does'nt want to go most days. been doing this for awhile , but now its getting worse. and i cant drive it.

over the past few months i have changed the dist cap, plugs, wires, map sensor, coolant sensor, injector in the carb, and checked vacuum hose's. i have not changed the oxygen sensor yet. i am starting to get po'ed i cant diagnose it. and with out a engine light i dont know how to get codes.

its a 1982 s-10 with a updated 1988 gm 2.5 engine ,wire harness, and computer. so i dont think is a engine light on this. and the motor swap has been in it for years . anybody have a suggestion ?.

[Just Piddling 0]

Just a stab, but have you checked the air intake system.

[TT-(Moderator) 1,169]

Try the IAT (intake air temperature) sensor, Perry.

It might be "fooling" the computer into thinking it's cold and enrichening the mixture.

I can't tell you where to look for it on your S-10 since I'm more familiar with the ACT sensors on Ford products. :omg:

[W9JAB 156]

:drool: "spits-sputters and does'nt want to go most days. been doing this for awhile , but now its getting worse."

My Grandma has the same thing! :omg:

[perry 82]

Try the IAT (intake air temperature) sensor, Perry.

It might be "fooling" the computer into thinking it's cold and enrichening the mixture.

thats the one i replace TT. on the intake in front of the carb. not the coolant sensor. i bought a new one and i was for sure that was it. but the gremlin came back days latter after i replaced it.

i have a complete engine sitting in the garage i pulled from my other s-10. allways ran great so i have been swapping parts and still no luck. next ill be swapping the complete engine.

[Rod(NASNUT) 1]

I would put the O2 sensor in it that will make it run rich. Did you check fuel press. also check the fuel filter.

[rallysman 0]

Sounds like the idle air control valve to me.

I've been able to clean sticking ones in the past, but if cleaning it fixes the problem then I would go ahead and replace it.

The IAC works like a choke would for a carburetor engine.

[crazy horse 0]

disconnect the battery,you should have a single wire 02 sensor,disconnect the 02 sensor this will put you in open loop.the computor should use a different strategy for fuel management.connect the bat and try.if this works its the 02.also the iac valve is for idle control and will not make a vehicle run rich. throttle positin is a big player also. check to see if the egr valve is stuck open. with the engine running place finger under the valve and push up, the engie rpm should drop and run rough if it is already running rough and no change it may be stuck open. good luck.

[perry 82]

im going to look at this today. forgot to mention, somedays the engine will just take off and race at a real high idiol. and then it go's away in a short time. this happens maybe once a week .

[KyBlue 655]

Really sounds like the TPS (Throttle Pos. Sensor) or IAC (Idle Air Control) is messing up, but I don't think that, that is all of your problems. If you've never changed the O2 sensor, it needs to be changed -

[pond195520032003 27]

Perry, also try the EGR Valve my brothers S-10 was doing kind of the same thing and he shot some PB blaster on it and pushed it in and out several times and it now runs better a new one is around $60.00 :drool:

[Coadster32 793]

So many sencors, but only so much money, and time. When it gets to be a potential 12 sencors, it might be cheaper to bring it to a shop. I'd do the fuel filter, Throttle position, idle air control valve, and O2 sencors myself. I only say this because I've been down that road. Alot of sencors will prob. never go bad. These ones are the most common to go, do the most controlling, and/or in abusive scenarios. Good luck. :omg:

[perry 82]

So many sencors, but only so much money, and time. When it gets to be a potential 12 sencors, it might be cheaper to bring it to a shop. I'd do the fuel filter, Throttle position, idle air control valve, and O2 sencors myself. I only say this because I've been down that road. Alot of sencors will prob. never go bad. These ones are the most common to go, do the most controlling, and/or in abusive scenarios. Good luck.

i have a complete engine and many other parts on the shelf for S-10's

i dont take anything to a shop but to get a frontend alligment.

[norman 0]

i have a complete engine and many other parts on the shelf for S-10's

i dont take anything to a shop but to get a frontend alligment.

From past experiences with GM tbi...... Check to see if the TBI base gasket isnt sucking air.... spray the base of the unit with carb cleaner (while running) to see if the idle fluctuates... This causes a rich mix and will not throw a code.....

Let em know

Greg

[iicap 1]

I know it's TBI, but I think there should be a fuel pressure regulator and it may have a vacuum hose on it. If the regulator is bad, fuel will be sucked thru the regulator to the vacuum side and into the intake manifold causing it to be running rich and sorta flooded all the time

[truckin88 104]

i had a 88 2.5, there is a MAF (or MAP) sensor on connected to the air filter housing, dirt cheap at napa, mine went bad, caused it to run rich and throw a check engine.

[norman 0]

How are u making out with the S10

[perry 82]

How are u making out with the S10

well not to good. its 7:30 pm and i still have'nt looked at it. got really busy this past few days. i work from home so i have'nt needed it yet. but i have a couple tractor huals this week that i have been blowing off so i have to get it fixed. tonight or in the morning. damn time flys.

you guys have gave me some good things to check. i am leaning towards its a vacuum leak. ill post a update.

[perry 82]

disconnect the battery,you should have a single wire 02 sensor,disconnect the 02 sensor this will put you in open loop.the computor should use a different strategy for fuel management.connect the bat and try.if this works its the 02.also the iac valve is for idle control and will not make a vehicle run rich. throttle positin is a big player also. check to see if the egr valve is stuck open. with the engine running place finger under the valve and push up, the engie rpm should drop and run rough if it is already running rough and no change it may be stuck open. good luck.

well when i started it tonight it was running rough. i changed the egr and egr sensor with the ones from my spare engine. no change. i had it running pushed up on the egr and it made it run rougher than it was.

i disconnected the battery and unpluged the 02 sensor. reconnected the battery and it seemed to run better so i took it for a drive. it ran fine. so i plugged the o2 sensor back in and it sstill running fine . as of now the truck is running fine. but i did'nt fix anything so it will act up again.

ill look at it some more in the morning. but its kinda hard to fix something when the truck is running good .

but i know as soon as i take off somewhere the damn thing will act up .

[Jim_M 179]

Well guys........that's why I drive a diesel. :omg:

[perry 82]

do you think the coil could cause this intermidiate promblem. ?. i just changed the o2 sensor , still the same. where is the fuel regulator ?.

i just got 2 more tractor hauls scheduled today. i have to get this darn thing fixed .

[perry 82]

i think i gott'er fixed . i tore apart the dash cluster and had to replace some light sockets and bulbs . the leaky windshield i had last year was'nt kind to the light sockets. so after i fixed that i had a engine light again. i jumped the A & B side of the test plug under the dash and it gave me a code #15. coolant temp sensor ?. well i replaced that last fall . i found that the conector plug was bad on the coolant sensor. fixed the plug, reset the computer and went and hualed in a tractor tonight and it seemed to run fine .

thanks guys for all your help :(