No fire... stumped.
Thread Starter
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Joined: Mar 2004
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From: Richmond Hill, GA
No fire... stumped. Has fuel, pressure is perfect.
Has spark.
Has air.
Will not fire.
Have replaced:
Coil/ICM good (assuming test ones were good. It does spark at the coil wire)
New opti.
Plugs/Wires brand new.
Will turn over just fine, no fire. I'm completely baffled at this point, and am open to ideas.
Has spark.
Has air.
Will not fire.
Have replaced:
Coil/ICM good (assuming test ones were good. It does spark at the coil wire)
New opti.
Plugs/Wires brand new.
Will turn over just fine, no fire. I'm completely baffled at this point, and am open to ideas.
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Joined: Aug 2004
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So it's firing at the coil but have you checked at the plug? Pull a wire or eight 
off one at a time and ensure that they are firing at the plug itself.
You're checking all the right things. Check your fuses....ignition, ICM, injectors, etc.
If all fuses are fine and you're firing at the plug, check injectors to see if they're clogged. Where are you checking fuel pressure....off of the pitot in the back of the rail?
If all of that is in working order, I'd say have a closer look at the ICM. You haven't swapped to OBD1 have you? Recently changed timing sets and removed the CPS?
Give those a try and let us know what's happening.
off one at a time and ensure that they are firing at the plug itself.You're checking all the right things. Check your fuses....ignition, ICM, injectors, etc.
If all fuses are fine and you're firing at the plug, check injectors to see if they're clogged. Where are you checking fuel pressure....off of the pitot in the back of the rail?
If all of that is in working order, I'd say have a closer look at the ICM. You haven't swapped to OBD1 have you? Recently changed timing sets and removed the CPS?
Give those a try and let us know what's happening.
Thread Starter
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From: Richmond Hill, GA
OBD1. I can understand an injector possibly being clogged, but even firing on 6 or 8, the car should run. Is and always has been an OBD1 car, there is no CPS 
.
Fuel pressure on the rail. 45 psi and steady.
.Fuel pressure on the rail. 45 psi and steady.
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Staging Lane
Joined: Feb 2005
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From: $oCal Goodne$$
Originally Posted by DietCoke
(This is resolved. Opti dowel on 120 degrees off, go figure.)
How can the opti dowel be off? Isnt' there only one way it could fit? Did you do a opti install and THEN try to start it? Or where you driving it and THEN it just stalled, and has never fired since?
Happy to hear you got it fixed.
Thanks.
Ruben F.
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Verdad Gallardo Thread Starter
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From: Richmond Hill, GA
Originally Posted by 1BigBird3
How can the opti dowel be off? Isnt' there only one way it could fit? Did you do a opti install and THEN try to start it? Or where you driving it and THEN it just stalled, and has never fired since?
Happy to hear you got it fixed.
Thanks.
Ruben F.
Happy to hear you got it fixed.
Thanks.
Ruben F.
But there was also a bent valve involved
so it'll be healthy again in a week when thats done with. Staging Lane
Joined: Feb 2005
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From: $oCal Goodne$$
Originally Posted by DietCoke
You would THINK it would only go on one way, but it can actually go on three ways. Opti was bad, replaced opti, wouldnt fire because new opti was installed wrong.
But there was also a bent valve involved so it'll be healthy again in a week when thats done with.
But there was also a bent valve involved
so it'll be healthy again in a week when thats done with.I see. Would you mind being more in detail on how it would "sound" when you would try to start it? Did it kick over and just "putt putt" for 1 second then die, or did it just keep cranking and until you let off?
Thanks, I am just trying to pinpoint this problem myself as I just replaced my opti, opti harness, ICM, plugs, coil, even swapped in a spare PCM I have to ensure everything is in working order. I still get nothing except, it cranks over (you could barely notice, it literally gives two "putt putts" and then dies silently as if it were never on. I have a ScanMaster installed and the LT1 just doesn't stay on long enough to register a DTC. Very frustrating.
The shop I took it to, ran diagnostics and says for some reason the spark is coming before the fuel.
I just want this problem fixed so I can install the Delteq system.
Ruben F.
O-ya, The OptiSpark that was replaced, only had 7k on it, yet when I removed it from the LT1, I shook it, and it sounded like a spray paint can. (The ones with the marble in it.) I can't wait to dissect this POS.
Joined: Nov 2001
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From: LT1 land...the "409" of the 90s!
Guys add to this. I recently had a customer who installed a new cap and rotor. with in a week the cap completely shorted out. Was a PITA to chase. We had fuel and fire. Every time I have had a car not start or run baddly when it had fuel and fire the opti in one way or another was the culpret.
I have about a Dozen of the darned things laying around now. the nice part is I hace some that probably just need a cap and rotor.(missing at high RPMs) so when ever I come across this problem I just slap one of those on to check. THis is easy to do for testing once you get to the opti. Leave the water pump and belts off and try to fire. If it starts right up you found the problem. If you are unsure slap the old one back on. We have even gone as far as swapping parts from the bad one to the good one till we pin pointed the problem.
I have also seen both styles of Optisparks installed wrong
Good luck!
I have about a Dozen of the darned things laying around now. the nice part is I hace some that probably just need a cap and rotor.(missing at high RPMs) so when ever I come across this problem I just slap one of those on to check. THis is easy to do for testing once you get to the opti. Leave the water pump and belts off and try to fire. If it starts right up you found the problem. If you are unsure slap the old one back on. We have even gone as far as swapping parts from the bad one to the good one till we pin pointed the problem.
I have also seen both styles of Optisparks installed wrong
Good luck!
