first off i will start by saying hello my name is rob and i just got a 86 IROC TPI Auto .... i have always wanted a iroc and now that i have one i am having big douts.... OK here is the problem i have to me it seems like a MAF problem but after reading all the other post I'm not sure... sometimes the car runs great and i have allot of fun with it and other times it runs like ****.. when it acts up i can only very lightly touch the gas and if i don't the car acts like it is starving of fuel and goes nowhere... the problem has increased in the last month almost to the point i dint even want to drive it for fear of needing to call a tow truck... it happens the most when i go to lunch at PM and if i pull over and turn the car off and let it sit for a few Min's it is fine but then the problem come back a few miles later... driving at night the problem is rarely there unless i drive for hours... but even then i let it sit with the key off for a few Min's and I'm good for the next few hours.... it almost as if the heat of the sun beating down on the hood increases the problum... is what makes it worse is that i am a engine machinist and am able to fix almost any thing but this really stumps me

please help

 

Have you tried a new ignition module in the distributor? They get hot and stop working with heat, but will work again like nothing happened after they cool down. About $35 I think, any auto parts store.

 

Or the pickup coil in the distributor. Turned out both were dying on my car when I bought it, and producing the same symptoms independently. Would run fine for 10-15 miles from cold, then the fun would begin. Especially on hot days.

Drove me crazy trying to figure than one out! Changing the module a couple of times half fixed the problem. Changing the pickup coil too nailed it.

 

I agree with the previous too posts. However, if you have to replace both the module and the pickup coil, I recommend getting a new distributor. It would cost you a little bit more, but you still have to take out the old distributor to replace the pickup coil. I am certain that you can buy a new high quality distributor with the ignition module and pickup coil already included for about $150. But make sure that you truly have an ignition problem first by checking for spark when the car is hot and acting up. A good place to start is a Haynes repair manual and a multi-meter. They have pretty straight forward procedure for testing your ignition coil and pickup coil. The ignition module you would have to remove and take it to autozone or o'reiley's where they will test it for free. But from the sounds of it it seems like you have issues with one or more ignition components getting heat soaked and failing, not an uncommon problem at all considering the age of these cars. I have already had to replace mine and my car is 5 years newer.

 

Yeah, I changed the pickup coil by getting a shiny new distributor! Was easier than stuffing around anymore with the old one.

But yeah, should start with basic troubleshooting - is there continuous spark, fuel, compression, vacuum, in the appropriate quantities, and try to find whats missing when it faults/dies.

 

i have tryed all those things .... i went out this morning the car did it off the batt i could not even get in traffic i had to pull off to the side...the reason i say it mite be the MAF is cuz i feels like it changes fuel trim through out the rpm range when the car is running some what good... when it craps out according to my wide band it is very lean....

 

Fuel pump?

 

Maybe it is going into limp home mode. Could be your ecm or prom man.

 

I would try going through it systematically. Do you have any stored codes in the computer? Check those first. Verify proper fuel pressure at the fuel rail. Verify that you have spark. Does the car act up only in closed loop, or does it also do it in open loop, when the engine is cold?

 

OK here is what i got... i have no codes or anything pending.... i have good fuel compression and fire... when the problem happens i still have all those things but can not go past touching the throttle even with the car in part u can mash the gas and it falls on its face it really sounds like it is running out of fuel but i have good fuel psi... good spark and good vac... that is what leads me to the MAF meter .... but what is the maf burn off relay.... what does it do? could that be my problem? where is it located?

 

I don't have a tpi. I do have maf sensors on my newer cars including the 4th gen. I know that i can disconnect the maf on the 4th gen LT1 and it goes into open loop and will run. Yes, it runs rich but it runs.

I can't imagine that the tpi is any different. I would unplug the maf and see what it does. If it goes into open loop and still fails, then it must be fuel delivery or ignition related. It would rule out o2 sensors and anything else that occurs in closed loop

 

You can check the TPS and make sure that TPS voltage is changing linearly and progressively. The other thing is to plug in a scan tool and start data logging when the issues occur.

 

definately try unplugging it and driving it like that for a while to see if it solves the problem. It may not run 100 percent good but if it is considerably better it should be that