Lt1 no spark
Thread Starter
Teching In
Joined: Jan 2014
Posts: 14
Likes: 0
From: Albuquerque, NM
Lt1 no spark 95 firebird with a 96 LT1 installed. Using OBD1 and wiring loom on 95. All extra wiring in engine schematic removed. New Accel optispark. Drag car using a turbo 350 tranny. Ok theres the basics. Got car put together, everything good all electrical works car starts and runs Ok, have to reprogram computer for cam. Anyway, make one test n tune shake down half track passes to make sure all good. Everything fine. Next Saturday go out make 4 runs, car doing good everything good. Sunday pull car out of trailer, drive down and back on return road, pull into our pit, idle it a few minutes, dies like always when you don't give some gas.(Cause cam and program). Hour later wont start, no spark at plug, no spark at coil, borrow a coil, same thing, start to diagnois. Only thing so far is that is no power coming into the PCM ign fuse on interior fuse panel. Any help would be great. Thanks
Teching In
Joined: Sep 2008
Posts: 25
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When it cranks it should show rpm if it does not then check fues if fues is good check for voltage at fues terminal if you dont have voltage at terminal then trace back your main power wire back to the distribution block. I had this problem on a few lt1 cars before and found the wire to be shorted out. Usually right over the fans.
TECH Veteran
Joined: Apr 2008
Posts: 4,985
Likes: 112
not regarded as very good. I would swap to another "known good working" opti. Ideally a AC Delco or Delphi Opti.
also use loc-tite on rotor screws....on your Accel the rotor screws "may" have come out. pull cap & check
you are making shake down runs "before" your tune???
also use loc-tite on rotor screws....on your Accel the rotor screws "may" have come out. pull cap & check
you are making shake down runs "before" your tune???
Staging Lane
Joined: Dec 2013
Posts: 59
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Since you dont have any spark at the coil the rotor is probably fine but always lock tite the screws on em cause they will back out. Use a noid light on one of your injectors, that will tell you if your optical sensor is working or not and you can go from there. If you get no flash off the noid light and you opti harness is getting the correct voltage on all 4 wires then the opti is the problem
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Teching In
Joined: Jan 2014
Posts: 14
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From: Albuquerque, NM
Don't think its theft deterent because I have Mitchell Pro Demand schematics for all wiring on car and it shows that it wouldn't crank. Starter solenoid circuit goes through theft module. Thinking maybe Optispark, but how can I be sure that's problem before tearing front of engine down?
Thread Starter
Teching In
Joined: Jan 2014
Posts: 14
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From: Albuquerque, NM
And what really throws me is if it sits overnight starts up fine next morning. Turn it off let it sit for 20 -30 minutes and nothing. No signal to injectors, which means no signal from optical sensor correct?
