I have an 85 IROC-Z with the 305 TPI. It is stock except for K&N filters, the screens in the MAF sensor are gone, a Hypertech chip and Flowtech shorty headers. It is running through the factory exhaust minus converter. Before the headers, my best time was 15.31 @ 89.5 mph. After the headers, it ran a 15.10 @ 91.5 mph. As the evening cooled off, it fell off. I pulled a plug and aside from some light carbon around the outer ring, the insulator is white. I need some ideas on how to go about getting more fuel to it. I think the car has more potential than it is showing. I would appreciate some input on this. Thanks in advance.

 

Lose that Hypertech chip, try your stock one and see what happens. How is the rest of your car? Good tune, fresh fuel filter. You could try an AFPR.

 

Descreening a MAF can make a car go lean. Of course on a stock car that is usually faster. But if you want to tune fuel, either get into PROM burinng (which for an 85 also kinda means ECM swap) or at least an AFPR.

 

What is involved to put an Adjustable Fuel Pressure Regulator in? Pardon the stupid questions, but fuel injection is foreign to me. Burning PROMs is outta my league.

P.S. Do you really think putting the stock chip back in will help?

 

Because Hypertech chips have a bad rep around here. We call them Hyperjunk and so many other names. The reason is they don't really do anything. They adjust timing across the RPM range and thats about it. 1-2 degrees. That wouldn't net the 10HP or whatever that they claim.

For what a pre-made chip costs you can get the stuff to burn your own chips. That's what they call burning proms.

Alot of those chips cause cars to run lean and behave poorly. The stock computer chip is really fine until you get pretty heavy into your modding. Also the default ECU is a learning computer. It learns your basic driving habbits. It's good enough like I said for stock applications.

Definatley the AFPR would do you some good. It's one of my next steps.

 

You might try switching back to the stock chip as suggested. When I bought my old 88 Iroc, it came with 2 chips and the stock one, I think it had and ADS chip in it and after I drove it for some time with that chip I finally switched back to the stock chip and at least to me it seemed to make a difference in the car, it just seemed like it ran and performed a little better.

Did you ever find if your car is throwing any codes? This is Brandon, the one who sold you that maf sensor btw. Since I sold that maf to you I was reading and read something that Jim85Iroc said about 85 maf sensors being specific for 85 cars only. That maf worked fine in my car, maybe its working okay in yours too, I dunno?? Maybe if Jim sees this he can pipe in and say something. I don't know much about 85's.

On my old 88 I made my own afpr via vaders tech article for the homemade one.