jackdiamondback

I have a 1986 IROC 305 TPI. We recently added GMPP aluminum corvette heads and a set of Pro Form self-aligning roller rockers. Previously added ACCEL HEI distributor and Super Coil, Hedman Elite ceramic coated headers and ACCEL 8.8mm wires. After putting the heads and rollers in, we discovered that we were making a ton of air, but not getting enough fuel out of the injectors, it won't hold an idle and it's going to run way hot when toodling down the road which will eventually burn a piston or two. I'm being told a bunch of different things and I'm trying to figure out who's right. I have ordered a BBK adjustable fuel pressure regulator, but I'm also being told I need to swap out the stock Prom chip. Is this true and, if so, can someone tell me if one of the standard Jet, Motorvation, Hypertech chips will work and which one? I'm trying to avoid the cost of a custom burned chip.

Morley

For the cost of a hypercrap etc chip you can burn your own.
All you changed were the heads, headers and rocker arms? Those alone shouldn't cause fueling problems. If you have the stock injectors in there you may have one or more that are bad.

jackdiamondback

I didn't have this problem before the head/roller rocker swap. What do you think about the fuel pressure regulator change to increase fuel flow to injectors? Thanks for the response.

jgifford

I would say that you are on the right track about AFPR. With higher pressure, it should push more fuel through the injector during it's pulsewidth. Have you checked you A/F ratio. I'm just curious, because, like above, I'm really suprised that from what you changed, there shouldn't be too much of difference. Also, you may want to invest in a NOID Light, to check an make sure all of your injectors are firing.

These are just a few places to start. Keep us posted.

Morley

Check resistance of each injector, looking for "around" 16 ohms. Anything much higher or lower than that is a bad injector.
With what you have done so far to your engine the fuel demand wouldn't have increased all that much. Now if you had gone to a much larger cam along with the other mods..then yes.