1992 Camaro Z28, L98 Rebuilt with mild cam and Custom chip. The cam is : http://www.summitracing.com/parts/CC...8&autoview=sku

What should the car idle at when it's cold in park? It used to be like 900rpm.. And now my mechanic has it at like 1,500 idle in park.. And then you put it into gear, it's around 1,100-1,200 rpm..

The tach now is fluctuating from around 1,200 - 1,500 (needle and engine rpm) with car in drive is bouncing back and forth (along with the actual rpm of the engine) when the engine is at temperature.

No Cats.

Mechanics are always having problems trying to time my car.. They complain how it stalls when they set it correctly and then dies when they put it into gear (rpm drops).. Took them 45 mins just to set the timing..

What should it be at?


More information

Here is where the car RPM is at during certain instances:

Car is up to temp.

Transmission in DRIVE (with foot on brake but not moving) - 1,000rpm
Transmission in PARK - 1,500rpm

Turn car off and immediately turn car back on.
Car idles at 800-900rpm in DRIVE (brake on, not moving)
Car in PARK - 1,000

 

Is this still TPI and if so timing should whatever the sticker under your hood says (which should be 0 degrees since it's computer controlled).

What cam do you have?
You might need a tuner to make you a custom chip those "performance chips" you get off ebay or a bunch of junk. In most cases they make less power over a stock car.

 

1992 Camaro Z28, L98 Rebuilt with mild cam and Custom chip.
What should the car idle at when it's cold in park? It used to be like 900rpm.. And now my mechanic has it at like 1,100-1,500 idle in park.. And then you put it into gear, it's around 1,000 rpm..

The tach now is fluctuating from around 1,200 - 1,500 (needle and engine rpm) with car in drive is bouncing back and forth (along with the actual rpm of the engine) when the engine is at temperature.

The cam is : http://www.summitracing.com/parts/CC...8&autoview=sku

No Cats.

Mechanics are always having problems trying to time my car.. They complain how it stalls when they set it correctly and then dies when they put it into gear (rpm drops).. Took them 45 mins just to set the timing..

What should it be at?

 

More information

Here is where the car RPM is at during certain instances:

Car is up to temp.

Transmission in DRIVE (with foot on brake but not moving) - 1,000rpm
Transmission in PARK - 1,500rpm

Turn car off and immediately turn car back on.
Car idles at 800-900rpm in DRIVE (brake on, not moving)
Car in PARK - 1,000

 

Took to mechanic, they now have it at around

900-1,200rpm (In DRIVE)
2,000-2,500rpm (Immediately when you shift to PARK)

What SHOULD the car be adjusted to in:

DRIVE ?
PARK ?

Specs:

Engine: L98 5.7L V8 350ci. TPI
Rockers : Aftermarket 1.7 ratio.
Camshaft: CompCam 08-300-08 - 206/210...450/480 (112)
Headers : Edelbrock TES
Gas: Using 92 (Well 91 since all stations are 91 now)
Chip: Custom programmed (not a pre-done one)
Cats: None (removed cats)

I was getting Error 22. They replaced TPS, and now I'm getting Error 22 again.
There is also a quick hesitation while driving around 2,500rpm mark

 

You're going have to do a few other things in order to get this sorted out, i think.

I did all of my adjustments in Park, warmed up.

The first thing i'd do is warm the car up and set the timing to 6 degrees BTDC. 0 degrees is incorrect. A stock L98 is 6 degrees. 6 degrees on a mod'd engine like yours will be fine until you complete the rest of the stuff i'm going to tell you. Make sure you set the timing with the EST wire disconnected. 6 degrees... plug the EST wire back up.

Now you can adjust the minimum air. Ground pins A-B on the ALDL. Turn the key on for 30 seconds. Turn the key off. Remove the ground. Disconnect the IAC connector. Start the car. Adjust the throttle blades until the engine RPM's are at 450-500. Turn off the engine. Reconnect the IAC plug. Now adjust the TPS to between .54 - .61 VDC. DIsconnect the battery for 15 seconds. Reconnect it and then start the car.

If you have idle issues after that, then you have another problem. Some possibilities are a bad O2 sensor. I had idle problems where the idle would be fine with the engine cold but once it was warm, the engine would surge/rev from 500-1000 rpms over and over. The O2 sensor was toast. You could also have a vacuum leak. That was another problem that I had. I believe the vacuum leak started all the problems with my car. The ECM tried to compensate for the added air, and it made the exhaust too rich. Thus the toasted, soot covered O2 sensor. if you haven't replaced it before, then spend the $18 and replace it. If it was recently changed, then remove it and inspect it for soot/damage.

My money is on making the above listed adjustments. I bet all the problems will go away once it's adjusted properly, even the code 22.

 

Thanks very much! I will be taking it to another shop tomorrow. So I know if they did it right when I go to pick it up. What do you think it should be idling at in DRIVE, and what it should be when in PARK?

Thanks :-)

 

Idle in park should be 750-850, in gear should be 550-650. Some engines will be 50ish RPM different. This is where my car sits and I just did all of the above listed adjustments. It runs perfectly.

Doing all adjustments when the engine is at operating temp is the key. Hopefully, the shop knows this. I'm sure a good tech does. Timing is key as well. You will notice small driveability problems if the timing isn't where the engine?ECM likes it. You will see unstable idle, backfires, missing, erractic idle, surging, etc. So you know, I've seen cars run 6 degrees of base timing, and others run 10 degrees. Largley depends on atmospheric conditions and engine mods. My car is at 4 degrees. It ran ok at 6, but I had an fading idle problem (idle drops slowly in gear, then picks up quickly, repeat). I also had detonation at WOT. 6 is a good place to start though.

Good luck finding a good shop. You sure you don't want to tackle this stuff yourself?

 

Im having the same issue as the above except im all stock. 1984 Camaro H.O. with L69 V8.

Everthing has been running fine up until a couple days ago. start it up when cold and will idle at 1500 rpm's in park. Ive gotten it to go back down to 600 rpm's but thats after sitting in the parking lot until it randomly decides to go down (there was one time when i reved it pretty high and shut my fan off when the rpms started coming back down and it worked) I havnt been able to do it again.

After it warms up i can turn it off and then turn it on again and everything will be fine.
In drive its around 900-1000 rpms warm or cold (This is before shutting it off and on) and park 1200-1500 rpm's warm or cold also.

To be honest I dont know if its TPI or not. I dont exactly understand the difference other then one is fuel injected and the other is air induction correct?

You may think im stupid but im just trying to learn anyway I can since I dont really have anyone to help me in person. And im in no shape to pay for a mechanic.

Stealth seems to have some knowledge whether its stock or modded.

Thanks for your input

 

Took car to a different shop and they tested the TPS and said it seems it's not getting the full signal so they suspect a broken wire in the TPS wire harness somewhere..

Same thing with me.. Shut off the car after it was warm and turn it back on and park would be back in around the 1,200 mark

 

I had another post I created and was asked about the choke light? Im waiting on a response for what it mite be.

 

camarosource, do you know how the shop is testing the tps?

 

It's at a new shop now and after testing, they said the TPS was not getting a signal and suspect a broken wire somewhere in the harness and that is what they are looking into now.

 

Replaced TPS was faulty, replaced TPS and AIC and works perfect now.