Okay, so thanks in advance for any responds or helpful comments!

I have a 1986 Iroc. It has a early model block from a 76 Camaro I believe. 4 bolt main. It is bored .030 over, has high energy comp cam, 1.6 rocker arms, 56 cc aluminum heads, and has custom programmed chip with a new Camaro ecm. I cannot get the car to run right what so ever.

When I have it in drive everything is fine except maybe lack of power, but when the car is warmed up and I put it in park from drive, the car will shoot up in RPMS and will get stuck around 1500-2000 RPMS. The car is set to idle around 800 RPMS.

I have replaced the solenoid under the plenum, I have bought an aftermarket adjustable fuel regulator and set my fuel pressure to around 24 psi ( because of 24lb corvette injectors) and now my mechanic is saying I need to switch out the rockers to 1.5 and maybe that will help. He is always busy and never has time to look at it, and I don't know anyone else that can fix the problem. Turning to you guys is my last resort or I will just have to sell it and cut my losses, which I do not want to do.

We timed it to 6 degrees, and it does not seem to be running as rich, and then we test drove it. After we timed it the Temp Gauge stopped working and I can't get it to work again?!

Also we were going pretty fast while test driving and we slowed down quite fast, and when we did we heard a popping sound coming from the right wheel, and then it sounded like metal to metal scraping. I cannot find out what the sound is. I just replaced the brake pads on the front. I would like to get this figured out as well so I can fix that problem.

Basically my head is spinning with constant problems and I have built this car from the ground up, I just want to drive it until the wheels fall off lol.

Please help guys, Thanks!

 

Anyone have any solutions/ideas?

 

Surprised the engine runs at all

Fuel pressure for TPI should be 43 psi @ idle ; vac line disconnected

24lb is the flow rating of the injectors ; not the pressure they operate at

 

Okay, that makes plenty sense. I was thinking that but somebody told me some bs story and I thought they knew what they were talking about. so set psi to 43? What should it be timed at? I have it timed at 6 degrees

 

disconnect the vac line while I adjust fuel pressure?

 

BUMP, still need all the help I can get please!

 

As I noted above

So what is it doing now with the fuel pressure and timing set correctly ?

Should ask your brake question in the BRAKE section

 

The only two things I know causes crazy high-idle is a vacuum leak and stuck throttle. IN a carb, I'd say check your choke.

Plug all your vacuum ports, see what your idle does when warmed up then. We'll go from there.


Oh, and welcome to TGO!

 

I checked for all possible vacuum leaks and I cannot find any. The car only has high idle when put into park. Right after I put it in park the Rpms shoot up like they should but do not come back down like they should, its like it gets hung up some how.

 

well, timing is set to 6 degrees, and let me set fuel pressure

 

Did you check the base timing with the EST bypassed or just running at idle? The ECM should adjust the timing at idle to around 15 - 20 deg. BTDC. So if it's showing 6 deg at idle without bypassing the EST, it needs to be adjusted. Some of this could be down to how it's tuned. It's difficult for us to give you any help without knowing how it's tuned for a custom build. What's your compression ratio? Do you have enough fuel or too much spark advance at higher RPMs? You should start with the basics like you are, but I would also check your minimum air speed, TPS voltage, etc. https://www.thirdgen.org/tpimod2. I don't think this will solve your problem, but it should help you figure out what isn't the issue.

 

The compression is 11:1, I believe it was set to 6 deg. while at idle. The ecm was custom made for the set up. The chip is set up to have the engine idle around 900 rpms. I believe too much fuel. I know that the fuel pressure was too high so the engine was trying to pack in as much oxygen as possible to compensate, but other than that, I am not to sure. Yes, the basics are the best place to start, that's why I have been replacing sensors. My mechanic is saying that I should switch back to 1.5 rockers to make more room for vacuum. What is your input on that?

 

@OZZ, thanks for the warm welcome!

 

Your 1.6 rockers should add more air right? So if you're getting too much fuel, going down to 1.5 probably wouldn't help. If it's running poorly and you think it's getting too much fuel, then the ECM can't lower the injector pulse width anymore. I would say something needs to be adjusted with the tune if that's the case and you're base parameters are correct. Was it tuned with the engine running or just based on the specs? Again, make sure that timing is WITH THE EST DISCONNECTED OR BYPASSED, or your base timing won't be correct. Just so this is clear, you're running a TPI system, right?

 

WOW I feel so stupid. Yes I forgot to mention this was a TPI set up. When we timed it the EST was disconnected. Yeah I thought the 1.6 rockers should add more air so when my mechanic said put the 1.5 to decrease vacuum I was sort of lost. I'm not sure if he knows whats going on with it at this point. I'm scared to take it to a shop because of the bill that might come of it lol. What would you say that the timing needs to be set to? Is 6 degrees not enough? If I set the Fuel pressure to 43 the car starts running really rich.

 

that's the thing when the car is at regular idle its fine, and when I drive there really isn't much of a power loss. The problem is when I put it in park after warm it seems to get hung up somewhere and gets stuck at 1500-2000 rpms. In drive it will stay around 800-900.

 

Some of that could be the spark advance? I remember using a very aggressive spark advance table and when i first ran the tune the idle was extremely high. It went down over time though. This was only after driving it though. When I first started it, it would be fine. I would check your minimum air speed or idle speed first with the other link I provided. Also, I'm not convinced how well the chip can be tuned without datalogging and tuning the VE tables and possibly some other specs. The VE tables can affect how rich or lean it runs, as it's how efficient the ECM thinks the engine is and is used to adjust injector pulse width.

 

Yeah I agree with you on the chip part. I mean it can be so many things, and it could even be the chip too. Idk. I'm going to go back over that link and read it over.

 

I know it's a pain to do the basic stuff, but if you get that right you can rule it out. Do you have the bin for the custom tune? Or do you have any equipment to datalog?