I was having some serious issues getting the car to start and idle - though the car has sat and not been ran for ~2 years.

Yesterday I ended up tearing everything out to get to the Opti, removed it and checked it, got it back on (so I knew it was on properly). I pulled the injectors (83#) and flushed them thoroughly, swapped the fuel filter, and ran plenty of new gas through the system. Cleaned the plugs, set the gap at .030" on all of them.

Now it starts every time, so I'm not sure what was the issue, but I seem to have fixed it.

Car holds an idle at 10"-12"Hg, which is a little low, but the intercooler isn't actually all attached. The car should run a little more vac at idle though. If Memory serves, it is a 218/230 116LSA camshaft (Bret Bauer designed) with 1.7 rockers on intake and 1.6 rockers on exhaust. Engine is not stroked.

I have checked to make sure I have +12V on all injectors, spark on all injectors. I have a noid light set and have used it to some success, so there is some signal getting to the injectors - I do not know if it is really consistent though.

The catback is not attached. It also sounds like it is backfiring a bit through the intake (can't say for sure).

Now this shot is from LT1 Edit, but oddly the o2 values are almost even. Typically the two are WAY off. I didn't log it at all, but I watched the two bounce around.


The Driver's Side primaries quickly climb to the ~350 degree mark.


But on the other hand, the Passenger's Side primaries stay 190-200 degrees. This is where the differing o2 values really show (I wish the snapshot I grabbed showed the differences, but it's idling so the o2 values are all over - but they are typically off).


Video!
http://www.youtube.com/watch?v=k0WQUEY1uxQ

Potential issues I think could be causing the problem:
-The timing set (cloyes double roller) jumped a tooth on the chain. Unlikely.
-The Injector Impedance Converter is either dying or having a serious issue running fuel to both banks.
-The rockers need adjustment
-Something else or Worse..

I'm going to take a few minute break to let the car cool down (I have a giant fan blowing at the engine, it'll cool the headers to ambient in ~20 minutes) and level my head. I could use a hand, I've been at this thing for days now and it's still full of Gremlins.

Any assistance appreciated!

 

MAP reading looks wrong at idle... should be in the 60-70 range.

Spark pug wires are wrong or valvetrain needs adjusting

 

Have you shot a temp of each cylinder on the passenger bank 2?

 

More timing needed at idle?

 

+1 on wires, maybe 2 were switched when reinstalling opti?? Seems like dead cylinders.

... also noticed you said "cleaned" plugs. In my experience, that doesn't always do the trick. Whenever I have a spark plug out, I install a new one.

 

While I had the rockers off to re-check the valve lash I did a compression test, within 5% across the board, so all is well there. Got the rockers set to zero lash now.

And I have a set of new plugs [and wires] coming first thing in the morning. Once they're in I'll get it going again, see if there's any improvement.

 

I too have FI app. 97ss 383/ D1 MM6. I have found that the engine will run very rich w/o the IC connected. This depends where you run your MAF. I run mine on the intake side of the compressor, so, it measures all of the air, and, I cannot dump air to the atmosphere. All air must go to the intake manifold. Some run the MAF on the pressure side, where, this should not be a problem.
High combusion exit temps result from running rich @ idle.

I also changed my open-loop afr tables to lean them out (low rpm and MAP values) @ start and idle. This helped me since I have 72# Seimens peak&hold injectors with an Acceleronics driver.

Also, you can check your driver grounds for possible mutiple circuit shorts. I had this problem many moon ago. It allowed for multiple injector fire (on-time), and (in my app), hydra locked @ cranking 1 time (good think I have forged rods).

B.

 

I think if the car is mechanically sound, he should start upping the timing at idle and see what happens.

 

Okay, I swapped out the plugs for new TR6's gapped at .030, swapped out the wires for new MSD units and an MSD blaster coil. I think two of my wires were bad (cylinders 4 and 6) even though they looked fine on the outside. - plugs? Who knows. But in combination everything seems to have helped out.

As soon as I had everything in, I tried to start it up - she's spinning way high in RPM, but it sounds better, no?

http://www.youtube.com/watch?v=Iw33eN1ds1w

I've started adding timing in since the video was taken (and adjusted the rockers and put the valve covers on...). I've got the timing up to 34 right now, and there are no issues at all.

 

Nice!

 

Any updates Geoff? Vids of some pulls, dyno time, etc?

 

Bueller...

 

She's sitting at the frame shop getting welding done... I'm hoping she gets back tomorrow with the exhaust tightened up (moved the lower downpipe 1/2" so we could get the low oil sensor in there) and the new supports welded in.

I want to drive this thing at full boost more than you want me to post details!