I ugraded my secondary injectors to 720 cc, from RP. When I put it all back together it's idling really rough with no acceleration power at all. 6-9 months ago had a new engine with carbon apex seals installed. Ran very well after that, a lot of power and quickness. It seems to be running rich, backfires after heavy deceleration. All the plugs are igniting. TPS set properly, BAC working. The only thing I can think of is a vacuum leak, but i was very attentive when putting the hoses back on. Any ideas?

 

check your boost sensor as i'm having the same problem right now with my 89. everything checked ok at RP but we couldn't check the boost sensor at the time. when you turn your ignition to on, your stock boost gauge should read zero. if not the that could be your prob. just dynoed mine and got 207RWHP with a stock motor,turbo and i/c. pretty sweet

 

I have a fuel cut bypass, the stock boost gauge is non functional. I have a mechanical boost gauge, reading from the intake manifold. So should I check the impediance and the voltage or what? How should I check the boost sensor, and what specs should it read. Thanks a lot for your response.

 

where did you get you fuel cut bypass? from RP? if you did your gauge should still work, it just wont read more than 8.6 psi. but it sounds like you car is just running that rich. it idles like crap because the bigger injectors are trying to flood the crap out of your motor. it has no power because its running dead rich. hell the fireballs popping should be a dead giveaway that your car is running way too rich. get something to control your fuel injectors. my advice is to get an apex AFC. its the best thing you can get for controling fuel.

 

It could be they gave you the wrong injectors. Sometime in late 87 I belive they changed from 3 ohm injectors to 12 ohm. This could be your problem. Check the resistance of your old ones and compare it to the new ones.

 

I don't understand why at Idle the secondary injectors would even be used. The primaries are still stock.