68CamConv

Ok so my son bought a 1994 Camaro with an LT1 6 spd. Recently the car has started dying when we push the clutch in. The rpms drop real low and ends up dying wether we push the clutch in or if we pop it out of gear with out the clutch.

We recently had the battery disconnected for 30 mins or so before the car started acting up and someone told us it lost the A/F ratio and needs to relearn. I think it is something else. We have driven the car and even let it idle for 30+ mins.

Fatdog2

Are there any codes?You can download GaryDougs 9495 scan tool free here onto your laptop and with a cable either made or bought plug it into under the dash and take the car for a run and then post the results here for diagnosing ,but I would do the cheap stuff first.
1. Replace gas filter if not done in a while.
2.Bad gas.
3.Get a can of throttle body safe spray cleaner and gently spray the mass air sensor,spray the throttle body blades inside and all the little holes and use Q-tips to clean out the little holes until clean (like cleaning a gun barrel).
4.The idle control valve in the throttle body may be dirty or not working .
5.Bad spark plugs,plug wires,coolant temp sensor in the water pump,ect.
6.Check all the wires and connectors to everything.
7.Go to Shoebox's site for diagnosing a lot of issues.
My money is on the gas filter or a dirty or bad connector to the idle control valve.
Also vacuum leaks,the list goes on and on.
Might post a signature so the miles and any mods and repairs ect.can
help out better here.Hope this helps.My02

Fatdog2

But you can save a lot of time getting the car scanned as mentioned earlier.This will pinpoint the area of the problem.My02.

68CamConv

thanks for the reply going to try cleaning MAF and IAC tomorrow and see what happens and work on recording when we test it. It is my sons car and he just bought it a couple weeks ago so not sure of all the mods. All I really know is it is a built lt1 to a 383 with about 18000 miles on it and tuned by someone out of south Louisiana. We are in NW Florida.

Injuneer

Did it run OK when he bought It? How long did it keep running OK before the stalling started? Did you make any changes under the hood immediately before the stalling started?

Without knowing the detailed modifications to the engine, it becomes very difficult to determine the cause. Do you at least know the cam specs, size of throttle body, type of headers? Does it have the emissions systems - EGR, AIR, EVAP, cats? What is the idle speed, engine fully warmed up? Is the SES light on?

When you disconnect power to the PCM, the long term fuel trims (LTFT) are erased from memory. LTFT's are the corrections to fueling that are required to meet the programmed 14.7:1 A/F ratio in closed loop (part throttle, low to moderate load operation). If the O2 sensors indicate the "normal" fueling is not meeting 14.7:1, the PCM "learns" the corrections required to bring the A/F ratio back where it belongs, and stores them in volatile memory. That's what is lost when the PCM loses all power. Once you start the engine the PCM starts to relearn. Idle LTFT's are learned in a matter of minutes. There are many LTFT's, one for the left bank, one for the right bank, for 16 combinations of RPM and engine load. Those are restored more slowly, until you manage to drive over the wide variations in engine operating conditions.

From Shoebox

Test IAC:

http://shbox.com/1/iac2.jpg

Reset IAC:

4th Gen LT1 F-body Tech Articles

68CamConv

I never road in the car before. But he never said any thing about it. battery was disconnected for 15-30 mins. Long enough to change the battery. I have driven it since and when you are coming to a stop the idle drops way low and dies once in a while it will catch and not die but not often. Does not matter if you push in the clutch or use gas to take it out of gear and then slow. We have let it idle for 10-20 mins a couple times and made 2 trips to and from store and still doing it.

Thanks for everyones help just new to this computer car stuff and new to the car.

68CamConv

Took CAI and throttle body apart to clean everything and found a vacuum line unplugged on the bottom of the elbow and 75% sure this was the problem. Not 100 because we cleaned everything. Car seems to be running fine now. Thanks for the input.