LT1 problems. No start.
Staging Lane
Joined: Dec 2013
Posts: 59
Likes: 0
How are you checking to see if your getting spark at the plugs? It sparks at a whole lot slower rythm at the plugs when cranking than you would think. If your getting spark at the coil but not on the plugs it has to be a problem with the rotor side of the opti. The front (rotor side) of the opti works just like an old school SBC distributor. Coil spark goes in and is transferred to the plugs through the rotor to, on to the posts, through the wire and into the plug. I had a problem just like this with my car but it ended up being something different (needed a tune). I figured out I could get it to crank if I held the gas pedal to the floor. Either way I went as far as taking the injector rail loose and popping an injector out of the hole in the manifold to see for myself that the injector was firing.
This is a great guide for an LT1 no start:
http://www.mainstreamtopics.com/foru...rt-diagnostic/
This is a great guide for an LT1 no start:
http://www.mainstreamtopics.com/foru...rt-diagnostic/
Registered User
Joined: Apr 2014
Posts: 42
Likes: 0
I did everything but the opti harness burnout, but my car wasn't running when I bought it and when I put my opti and plugs and wires in my car fired right up and ran good for a week and then my car started stalling randomly and now it doesn't start at all and my.opti is covered in coolant so I think my opti failed agian
Registered User
Joined: May 2014
Posts: 3
Likes: 0
From: Detroit
Also check for bad wires I had one that was green and corroded i followed it down and it was split in half these cars are pretty old. When the opti went bad in my car it cranked a couple of times then after that completely stopped my water pump leaked on it. As soon as I replaced the water pump and opti it fired straight up.
Registered User
Joined: Apr 2014
Posts: 42
Likes: 0
Burnout,
check your Icm wire harness there is a ground wire two hot wires and a white wire! Make sure that when you check the white/black stripe wire crank the car its the remote wire that your pcm sends out a signal to the icm pretty much saying ignition ready
hope this helps
check your Icm wire harness there is a ground wire two hot wires and a white wire! Make sure that when you check the white/black stripe wire crank the car its the remote wire that your pcm sends out a signal to the icm pretty much saying ignition ready
hope this helps
Thread Starter
Registered User
Joined: May 2014
Posts: 15
Likes: 0
From: Dallas, Texas.
The dudes at the shop are saying my coil and icm are fine but that in some way i still have injector pulse and no spark... makes no damn sensr to me. Lol. The last shop i took it to actaully crossed the two hot wires on the coil and shorted the wiring out. It even began to smoke. They think that it might have fried the PCM. The one i just rebuilt... is that possibile?
Burnout,
check your Icm wire harness there is a ground wire two hot wires and a white wire! Make sure that when you check the white/black stripe wire crank the car its the remote wire that your pcm sends out a signal to the icm pretty much saying ignition ready
hope this helps
check your Icm wire harness there is a ground wire two hot wires and a white wire! Make sure that when you check the white/black stripe wire crank the car its the remote wire that your pcm sends out a signal to the icm pretty much saying ignition ready
hope this helps
Thread Starter
Registered User
Joined: May 2014
Posts: 15
Likes: 0
From: Dallas, Texas.
Damn, that sounds like opti hit the fan again.
I did everything but the opti harness burnout, but my car wasn't running when I bought it and when I put my opti and plugs and wires in my car fired right up and ran good for a week and then my car started stalling randomly and now it doesn't start at all and my.opti is covered in coolant so I think my opti failed agian
Registered User
Joined: Apr 2014
Posts: 42
Likes: 0
I'm going to have to guess and say you fried somthing unfortunately
There's a chance you didn't harm anything but the wires though if it smokes long enough and your not getting power to the wires you smoked you fried It
There's a chance you didn't harm anything but the wires though if it smokes long enough and your not getting power to the wires you smoked you fried It
Registered User
Joined: Jul 2016
Posts: 1
Likes: 0
No spark Hey hypno92 i know this is probally unlikely i actually did thia working on my firebird at night with lights and plugged the opti up backwards. It wouldnt fire changed coil, icm , timing chain and troubleshooted for days but just figured i would show my mistake to try to help you out.
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