82 Stalling problems

[flynbyu82]

I have an '82 Vette that I recently purchased, and I'm having some stalling problems. It tends to idle low, around 800rpms when I'm at a complete stop, and always seems like its just going to die out, barly pushing enough power to stay on. But, at random times, the car will actually shut off, always when I'm at a low speed, like right after I brake to a near stop. For example, after a speed bump when I start to accelerate again. Im not too sure what exactly it is. It's like it doesn't downshift when it should. When it shuts off, it seems like something with the idle gets pulled down by lack of vaccum, to around 400-500rpms and then shuts off.

 

[Daryllawman]

Hello...I don't have a answer for you on this problem, but someone soon will chime in....Just wanted to welcome you to the Corvette Action Center

 

[jdp6000]

It doesn't sound like a vaccum leak. 800 is not a low idle for these cars...thats actually high.

It could be many different things. How does the car run otherwise?

There is some basic stuff you can check. Is your rad full? the CTS wont work if it isn't. FWIW 82 runs on the MAP and CTS on start up. when the car warms up fuel delivery and mixture is determined by the CTS and O2 sensor. You got to have a thermostat...do you???

Do you get any engine codes?

When is the last time you decorbonized the throttle body?

What does your oil pressure guage read when it does this. Low oil pressure tells the ECM to stop the fule delivery.

Anyway, can you post more information. what have you recently replaced??? Engine Codes? Performance on start up and driving performance. Well figure it out.

Jim

 

[flynbyu82]

I do have a coolant leak, I just replaced the thermostat and gasket. I also replaced plugs, plug wires, and alternator. I don't know much about the CTS system, how would I check the engine codes?

Perfomance wise, it starts fine. Turns over quickly. When the car is in drive, it seems almost like it has too many gears and seems to drive better in 3rd gear rather than drive because it doesnt feel like it's lugging so much. That doesn't seem to help the problem of RPM drop and engine stall occasionally during deceleration and/or stoping.

I'm going through everything on the car to make it more of a daily driver, replacing things like U-joints and suspension, and I'm just trying to make this a reliable car for every day driving.

 

[WayneLBurnham]

Same as Daryl, don't know, but WELCOME ABOARD!

The system is a pretty unusual one - all I can recommend is if you don't find the problem reasonably quickly, take it to a decent vette-only shop near you and have them diagnose it. That would also serve as a good way to test to find if you found a good shop or not.

There is a site that started here or on CF (or both) that is dedicated to the CrossFire cars (I guess that's '82 and '84 only.) I don't have it handy though. Maybe this is a common enough symptom of a known problem, like JDP was mentioning.

 

[jdp6000]

Engine light goes on when you trip codes. Stored codes can be retreived. Remove the ashtray. Under it is a plug. Get a wire and insert it into the two plugs closest to the driverside, turn the key to the on position but do not start the car. It will flash once then twice (represents 12), it will do it 3 times, then the codes start, it will blink then pause then blink, each blink is a number for example 42 is 4 blinks pause followed by 2 blinks. At the end it will blink 12 three times. Its the blinks between the 12's I need.

The CTS (coolant temp sensor) is at the front of the engine, right infront of the thermostat. Low coolant will throw it off. Try filling the rad and reserve up to the mark. See what happens.

Jim

 

[Twin_Turbo]

There is a site that started here or on CF (or both) that is dedicated to the CrossFire cars

??? started here or at cf ??? it's http://www.crossfire.homeip.net

As for the system, it's not different from any TBI system w/ the only exception that it's got 2 single TBs instead of 1 dual so it has 2 IACs but they are parrallel wired so similar to just 1 (it's a spliced harness).

 

[wishuwerehere82]

You may need to tune your engine for the first time, since you just got it and it doesn't sound like it's running quite right.
Make sure your intake manifold bolts are tight on top of the manifold tub and that there are no vacuum leaks to the AIR pump, MAP sensor and EGR valve. Bad IAC motors will cause your idle to be erratic too.
It's normal for the 82 700R4 transmissions to feel like they are shifting forever. Between the torque converter lock up and the overdrive they feel like they have about 6 gears.

 

[bill81vette]

welcome to CAC!!! enjoy the vette and the forums!!!!!

 

[flynbyu82]

I checked for engine codes, but it just repedeatly flashed twelve. Is there anyway I could have recent it or anything?

Thanks for everyones help

 

[wishuwerehere82]

Twelves are good. That means nothing is malfunctioning in the control system. It can still run like cr&p and not throw codes though. The main way to reset the ECM is to pull the fuse in the battery box for 20 sec.or disconnect the battery. The ECM will not store codes unless they are active in memory. In other words, if the light isn't on, there are no codes.

I would check timing, fuel pressure, and TPS voltage first to see what everything is set for. Here's a good article on how to do it.
http://corvettefever.com/techarticles/4688/

 

[flynbyu82]

Alright, when the car would shut off, the engine light and battery light when come on, but I geuss that would happen with the car just shutting off.

If the coolant level was low, would the engine light show that as a code? Because of the leak, I will just fill it with water (to the right level) as needed. I will also do what I can with the check up you just showed me.

I appreciate all of the help. If anyone has anymore suggestions I will be more the appreciative of those also, and I will definitly check those out too.

Thanks a bunch