Duckgawd

Ok, I just recently took my car to get painted, and after I got it back I knew it wasn't running right. When I drove the car home, when I came up to a red light and pushed in the brake, the rpm's would drop, and then instead of leveling off around 750 or so it would jump down to 500 and then would stall out. Does anyone have any suggestions for me?

CHVYPWR

I'd check the idle air control (IAC) for carbon build up on the tip first. Does it smoke out the exhuast at all when this happends??

Duckgawd

I was reading in another article in the board and the guy said he restarted his computer, I was wondering if that could help, because a few months back my car was running rugged and I switched the Oxygen sensor and the car was running well, and when the car got painted they disconnected the battery because the CD player was reseted, so if that is the case how do I reset the computer back to the way of before?

89camaroRSV6

whats the revs ...when u idle in park

temp solution ..raise the idle revs a little by adjusting the screw on the TBody

92RSMuscle

iTrader: (1)

this happened to me. after sinking 1000 bucks into it i did this
smack the sides of each of the EGR cylanders...sometimes the pump gets stuck...thatll do it...then clean out the throttle body with some starter fluid or wd 40

started right up! hasnt failed since

Duckgawd

My car is MPFI, and some of the people who have looked at the car think it is a vacume problem, what would you say would or could be wrong in the vacume aspect?

Bluerocket

Is It a auto or manel Becuase my car did that to when I had a vacum leak to the decealartion valve it is the thing that looks like a can (only on a manuel) Its on the left of the intake manafold on the alterater bracket

Duckgawd

The car is an Auto, but I am starting to wonder if the power brake check valve is not working right, I was going to replace it tommorow and see what happens.

CHVYPWR

Have you checked the IAC yet?

Duckgawd

Were is the IAC located, and how do I know if it is not right?

CHVYPWR

The IAC is located on the passenger side of the throttle body (TB) right on top, right by where the rubber air intake hose connects to the TB, right above the TPS. It'll have a 4 pin plug going to it with 2 blue wires and two green wires. You'll want to pull it out and clean off any carbon build up on the tip and the seat the tip sets into. It just unscrews like a bolt.

TomP

I like 92RSMuscle's idea of the EGR valve. Does the car stall all the time? Will it stall when it's "cold" and just started, or only when the car is hot?

To re set the comptuer, disconnect the NEGATIVE battery cable for a minute or so. Reconnect the negative cable. Important: Go for a drive that is at highway speeds! Drive 1/2 hour away from home, and then you have to drive a 1/2 hour back. This helps your computer re-learn the engine faster. If you drive around town, stopping at stop lights, and going slow, the comptuer doesn't gather enough data (higher speeds, engine not warm so it doesn't go into "closed loop" to read the oxygen sensor, etc), and the comptuer will take forever to re-learn itself.

Good luck... hey, how'd the paint job come out?

Oh and see this message for info on cleaning the IAC: https://www.thirdgen.org/techbb2/sho...threadid=61408

RBob

iTrader: (1)

Duckgawd, if the engine is a 3.1l ('90-'92) an idle learn procedure
is required. This needs to be done every time the battery has been
disconnected.

Let me know and I'll find & post the procedure tonight.

RBob.

Duckgawd

Ok well first how to you do the idle procedure that I need to do. I replaced the power brake check valve and the hose that runs from there to the engine and that seems to be working decient, but it still runs a little sluggish when it stops. the paint job look nice, I had them take off all the side molding, and the pin striping along with the firebird logos on the front and the two sides. The car looks real nice.

Thanks for all your help

ChevyCarnage

My Firebird is doing the EXACT same thing. If I put it in neutral and hold down the gas a little while stopped at a light, it dosnt stall. But as soon as I stop without giving it a little gas, the RPM's drop below 500 and it stalls. Mechanic told me I'd need an engine rebuild but I think the guys a moron. He hasnt done anything right for me yet.

TomP

Carnage, look into the IAC cleaning link that I posted. What year is the car, Duck?

RBob

iTrader: (1)

Here is the idle learn procedure. This is ONLY for
S/D (non-MAF) engines. Typically the 3.1L and also
the 2.8L's that have been recall converted to S/D.

Disconnect battery, pause 10 seconds and reconnect battery.

DO NOT TOUCH THE THROTTLE AT ANY POINT.

Set brake and chuck tires.

Start engine, let settle a bit and put trans in drive.

Let run until fan cycles on then off.

Turn off engine.

Wait five minutes.

Start engine and place in gear.

Let idle for five minutes.

Shut off engine.

End of procedure.


If the throttle is touched at anytime during this you have
to start from the 'disconnect battery' again. If the engine
stalls at any point just restart and place back into gear.
I do this with at least the A/C and rear defroster off. And
don't turn the steering wheel either.


RBob.

KED85

Want ot know what it is?
Alternator.
I just replaced mine.
My car hasn't had such pep since I installed the 3.4.
I swear, brake lights take juice. So does fan motor & ......
Watch your battery gauge and see what happens.
I'll bet it's your alternator.

ChevyCarnage

I'll do that, as soon as I find out exactly what the IAC is and where
thanx a lot man.

Motopsyco

Ive had this happen before on my T/A, check the temp sensor wire, not the wire for the guage but for the sensor itslef, i had a loose wire, and it would do that

--Stormr

Duckgawd

My car is 90 3.1 V6, Over the weekend I will clean the IAC and then I will to that procedure after I turn off the battery. Then we will see what happens. Hopefully it is running back to normal.

Thanks for the help, I will get back to you guys.

mw66nova

iTrader: (13)

i had a problem with this before, i changed the brake booster and the thing acted fine, check that by taking the vacuum hose out of the brake booster, shove a big bolt or something in the end and the go press on the brake (while running), if it stays running then you know that your brake booster is bad.

Duckgawd

Yes, that is what I have been playing with, that is what I have first thought and I changed the check valve that connects to the brake booster and seems to be helping, but it still runs a little funny it idels around 600 to 650 which isn't to bad but it should be around 750. now if the car doesn't stall anymore, do you think I should still change the brake booster or should I leave it?

TomP

Like Mw66 said; if you plug that vac line, and the car acts normal, then it's the booster. If there's no change, then it's not the booster, and leave it alone.