94z...horrible misfire...
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Joined: Jan 2013
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94z...horrible misfire... Hey guys hope I'm posting in correct place. I'm working on a friends 94z..he just
Got it a couple months back. Has all the usual bolt on stuff. It started misfiring, at high rpm and began shutting off at random times. Naturally I replaced the optispark.
Still the same issue. ICM tested good at advance. Haven't checked fuel psi yet.
The service engine light has been on since he's had it..after changing optispark the service engine light now flashes..BTW car runs hot then cools down..then same cycle
All over again. Any help greatly appreciated. For what its worth I want an ls1. Sick of lt1s.
Got it a couple months back. Has all the usual bolt on stuff. It started misfiring, at high rpm and began shutting off at random times. Naturally I replaced the optispark.
Still the same issue. ICM tested good at advance. Haven't checked fuel psi yet.
The service engine light has been on since he's had it..after changing optispark the service engine light now flashes..BTW car runs hot then cools down..then same cycle
All over again. Any help greatly appreciated. For what its worth I want an ls1. Sick of lt1s.
flashing cel is multiple misfires that endanger harming the catalytic converter. Check fuel pressure also have advance test the icm a couple of time not just once enough for it to get good and hot.
On The Tree
Joined: Jun 2008
Posts: 164
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From: Hallandale Beach, FL
dont trust those advanced testers, also look at coil could also cause misfire, check basics first before jumping to big things like opti. check all wires and check all plugs. I would recomend replacing icm no matter what they say and if doesnt solve the priblem just return it
TECH Regular
Joined: Apr 2011
Posts: 441
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From: Deep in the heart of Texas
Coil, ICM, plug wires, plug wires not seated properly on the spark plug, Spark plug fouled or gap improperly, Loose rotor, Swapped plug wires after opti change and finally bad replacement opti. Who was the maker of the opti?
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Joined: Jan 2013
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Hey thanks for your help guys. Sorry I haven't replied . I replaced the
Entire ignition system. .except plugs and wires. His Chevy dealership had did
That recently. Ac delco plugs
.. problem is 10 times better . I data logged
His car and it has horrible knock at 1500 3000 and 4600-5000. In the
Last rpm band it climbs 7000k counts. In a 1 mile drive with one wot run it showed
14000k...this is new to me. I cannot hear a knock...that's a $#@t ton of knock. Option was a 80$ eBay . Knock on wood mines lasted 30k miles . Bad knock sensor maybe?...this guy freaking drives the crap out ta the car. I'm in no hurry to get it right
Because I'm sure its ready to blow anytime . Lol
Entire ignition system. .except plugs and wires. His Chevy dealership had did
That recently. Ac delco plugs
.. problem is 10 times better . I data logged His car and it has horrible knock at 1500 3000 and 4600-5000. In the
Last rpm band it climbs 7000k counts. In a 1 mile drive with one wot run it showed
14000k...this is new to me. I cannot hear a knock...that's a $#@t ton of knock. Option was a 80$ eBay . Knock on wood mines lasted 30k miles . Bad knock sensor maybe?...this guy freaking drives the crap out ta the car. I'm in no hurry to get it right
Because I'm sure its ready to blow anytime . Lol
