Ok I've got a 1982 Z28 with the crossfire system on it. It seems like it has weak spark because fuel delivery seems to be on point, ive got 10 PSI pressure at the filter up front, and the injectors deliver a nice conical spray. but the motor runs like ****. He's what Ive tried so far. I have a code for EST trouble. I replaced the entire dizzy with a known good one form a cfi car that ran. I also tried two coils. two syptoms that bother me is the tach bounces all over the place, it missfires like a son of a bitch, and ive noticed that as soon as i turn the car off, the fuel pressure bleeds off almost instantly. what do you guys think?

 

no one?

 

So test the spark. Buy a less-than-twelve-dollar spark tester, see what happens.




If the ignition is interrupted, the tach will drop. When the ignition comes on-line again, the tach works again. First three things that come to mind:

• Loose wires/poor connections on the power supply to coil
• Loose wires/poor connections on power supply between coil and distributor
• Defective pick-up coil (but you've already replaced the distributor)

Is the cross-fire system supposed to retain pressure? The other GM TBI systems don't.

 

i was unsure on the fuel pressure, as for the bouncing tach, i mean this things bouncing FAST, as if it were on a rubber band and someone flicked it

 

10 psi seem a bit to low, every thing I read It says to have at least 13 psi. my crossfire liked 14-15 psi. also check to see if your throttle bodies are sync together. google search that, plenty of articles on it.