I have searched and not found anything with these same symptoms. I have been trying for three weeks to fix the car and have got no where and would really appreciate it if anyone can give fresh ideas.

First of all, what started all this was my crank hub flew off the car going down the highway due to no key in the crank. Got a new crank for free from a friend and replaced. Engine spins great by hand, not too easy or hard. Timing marks where lined up on crank and cam(dot to dot) ,and away we go.

Not quite. Messed up and had timing 180 out. Started shooting gas out of the intake manifold which fouled out the opti spark because of gas thru the vent tube. So replaced the opti spark again and be good.

Wrong. Car lost injector pulse and spark at once. Re-did ground connections and got injectors and spark back. Then lost spark. Tested ICM at Napa, tested good(by the way only 6 months old). No spark from coil. Changed coil out. And crank sensor just because it had been suggested it was the problem was replaced as well, and plugs. Checked all plug wires,good. MAF sensor wires good as well. Car still no start. Has spark to all eight cylinders but no spark. Scanner throws p1351, same code I always have. I will say spark is weak and slow if that helps any, but the opti is installed in the middle(square) location.Basically not the retarded or advanced location.

The white wire from the ICM shows as a ground with key on and ground test blinks on and off while cranking.

Fuel pressure is good. New adjustable set right at 44-45psi. All eight injectors are still pulsing. Car will crank all day long but never start. We have held the throttle body open as well and no change. We cleared the codes several times and never got anything other than the 1351. Please help, I am losing my mind, my fiance's mind, my buddy's who has been over here almost every night helping(one with the scanner), and his girlfriend's mind.

 

I hate to say it, but it sounds like the opti. Or the opti harness, or coil wire.

 

So even though it is getting spark, it is most likely the opti? When my last opti went out, there was no spark. It's ok if that is the answer because I have a waranty on that part, but just replaced it a few days ago so was thinking that couldn't be the problem.

 

Well if you changed the opti a few days ago, then its probably fine. The one thing that catches my eye is where you said you fixed a ground and got spark back, and then lost it. I would double check your grounds again and throughly check your opti harness.

 

Also the scanner wasn't saying anything wrong with opti. We found a couple of ground wires with bad connectors that we replaced. But will check again. Could 1351 prevent full spark or something? I don't even know if that is possible just kicking around ideas.

 

ya lost me with that one

it really sounds like the opti harness to me, and it would not be a bad idea to pull the plugs and get a look at them before you do anything else, make sure they are not fouled from it not working at one time.

 

the worst thing you can do is assume a part is good because it is new, not saying i think its the problem just dont skip it in your diagnosis because it is new

 

sorry about the typo "spark but no spark". Meant spark but no start. The scanner was reading a signal from opti.But maybe a weak one. I will check harness from opti back. I pulled the new plugs again sunday night, last time working on it, and they looked fine. Not burnt or fouled.

 

I didn't get the "opti is installed in the middle location" part, I don't know if that has something to do with the spline drive or not. Could you have indexed your opti incorrectly?

 

P1351 is for an open circuit on the IC Module. That would certainly affect the spark. Have you run the diagnostic on the IC Module?

And your crank hub didn't fly off because of "no key in the crank".... there is no key in any stock LT1 crank hub.

 

He has a 97. It uses the cam dowel pin. On the three holes in the back of the Opti, only one has an enlarged, square hole intended for the dowel pin. Only 93/94 unvented Optis use the splined shaft.

http://shbox.com/1/opti_back.jpg

 

If you have spark at the plugs i would check the following.
Coil Wire, is it connected really good to the opti and coil...id there any corotion on it?

Opti, I am going to guess that you put it on wrong adn the opti is not fireing at the correct time.

Also you said "the car was 180 deg off" How the hell did that happen with only replacing the crank? Did you also do a timeing belt or something?

 

Injuneer, you are correct that the crank is not keyed. However, several engine builders in my area advised me that a woodard key is supposed to go in the factory slot in the nose of the crank. Here is a jegs part Item# 720-984G for example if I am calling by th wrong name. But it does act as a key to prevent the hub from moving side to side. I will also agree that the main cause of the hub spinning off was the machine shop using the wrong thread bolt on th crank hub which allowed it to move. But if that "key" had been there....maybe only the bolt would have come off. And no, I will not use them again.

Formula,

We did not mark the location of the cam or note what cylinder we were on when we pulled th crank. Long story short, the opti was firing on 1 put the #6 cylinder was up. Easy fix but ruined the opti in just a few seconds when the gas went thru that vent tube. The opti iself is installed right at this point and has been tripple checked.

I think the "weak spark" could be related to the icm code, as has been confirmed by others here. I will try to trace this down and report. I will also check the harness from th opti, although I don't think it is the issue.Also, yes the ICM was checked out, though we did not do it with the scanner. Took it to napa and it tested fine

Thank you all for your feed back.

 

This is what I wasn't getting:
I thought the only opening that the cam dowel pin could go in was the square one, i.e. no retarded or advanced location, only the right location and two wrong locations. That's why I didn't get the middle one, I was thinking 'did he mean the only one?'

 

You are probably right about that. I assumed since there are three locations, the other two advance or retard respectivley. Either way it went in the square one.