Feb, 2004, The %$#@ing car won't start

2/29/04 update: Its alive!!!  What did I change?  I hooked the VersaFueler back up (still running stock injectors, remember).  I had decided to check the injector harness again with the noid light.  The light lit dimly as soon as the ignition turned on, then it pulsed dim/bright/dim/bright/dim when I cranked the engine.  So I hooked the VersaFueler back up and tried the test again.  This time the noid light was dark with the ignition on and pulsed off/bright/off/bright when I cranked the engine.  Time for another start test.

Figuring the engine was still flooded, I unplugged the fuel pump fuse.  After a couple of seconds of cranking it started.  Didn't run long without any new fuel coming in, but very encouraging.  I plugged the fuel pump fuse back in, twisted the key, and ZOOM, started right up.  And no cherry bombs.  It ran about 20 minutes total and sounded very healthy.  No bad noises and no oil leaks.  Stayed nice 'n' cool.  Time to celebrate!

2/28/04

Last summer it became obvious the engine was wounded.  The most solid clue was the bits of piston ring I poured out of the y-pipe.  The engine repair and mods will be detailed on another page, for now I'll just say that I swapped the old GM LT1 heads and intake for a set of Blackstone-massaged AFR 220cc LT4 heads and an LT4 intake.  Because the AFR heads have 74cc chambers instead of 54cc like the old heads, the new pistons have much smaller reverse domes. The theory is that this will make them much stronger than the old pistons, which lasted all of about 300 miles.  Compression stayed at 8.5:1.

Fast forward to early February, 2004.  The engine is finally rebuilt and in the car, ready to fire.  And fire it did, as soon as I turned the key.  It sounded fine, the same as always, except that it would produce occasional cherry bomb blasts from the exhaust.  After 1 to 2 minutes of running, it let fire a cherry bomb blast that was so loud I immediately turned it off.  I checked the plug wires on the Opti to see if I had crossed a pair, but they were all correct.  Then I adjusted the valve lash, but it was fine, too.  So I decided to just fire it up again to see what happened.

But it wouldn't start again.  Three weeks later, as I write this, it still hasn't started since that first time with the cherry bombs.  This page describes everything I've tried to get it to start, then begs for help.

Symptoms:

After sitting for a day, sometimes it will try to start a little.  I have one DataMaster log of a start attempt that shows the revs reaching about 1000 rpm and the block learn cell switching to cell 16.  But right after that the revs dove straight back down to zero.  After the little "first thing in the morning" sputter, no amount of cranking will show any life at all.

A typical start attempt is to turn the key with 0 throttle and let it crank for a few seconds, then go to 100% throttle ("clear flood" mode) for several seconds, then back to 0 throttle for a second or 2, then vary the throttle all over the place, then give up.  I've cranked it for 3 seconds and for 30 seconds.  Other than the first try of the day, at no time does the engine even think about starting.  It's just as if the ignition was disconnected.

Stuff that is the same as last year, and shouldn't affect starting anyway

- block
- crank
- rods
- pins
- timing chain
- cam
- lifters
- water pump
- intake system (blower, intercooler, and plumbing)
- alternator
- starter
- fuel pump

Stuff that is the same as last year, and could affect starting

- all sensors (MAF, MAP, ECT, TPS, IAT, O2)
- fuel regulator
- PCM tune
- spark plug wires (MSD wires with 300 miles on them)
- coil (Crane PS91)

Stuff that is different, but shouldn't affect starting:

- pistons
- rings
- bearings
- oil pump
- oil pan
- valve covers (yes, I finally replaced the old, mutilated stockers)

Stuff that is different, and might affect starting:

- heads
- intake manifold
- intake rockers
- pushrods
- fuel injectors (I'm running stockers for break-in) rather than the 95 lb/hr monsters I usually run
- reprogrammed PCM for 24 lb/hr injectors.

Important parts that are brand new (zero miles):

- Opti
- spark plugs (street heat range Autolites gapped at .040)

OK, here is the testing I've done so far:

- DataMaster reports no PCM codes during cranking or when it has actually tried to start
- compression check on all cylinders: good, 130 +/- 10 psi (remember: 8.5:1 and big cam!)
- spark energy on cylinders 1,3,5,6,7, and 8 using screwdriver in plug boot grounded to nearby metal: good, nice blue spark
- fuel pressure during cranking: good, 45 psi
- checked all injector connectors with a fuel injector test light (noid light): good, all injectors are being told to squirt
- checked flow of 1 injector attached to fuel rail (others disconnected): good, saw expected fuel pulses
- checked all 8 injectors on the Acceleronics flow bench, then ultrasonic cleaned them: good, they all flow about the same
- checked all PCM power and ground signals at the PCM connector: good
- programmed PCM for speed density mode and removed everything in front of the throttle body: didn't make a difference
- with all intercooler plumbing reconnected, pulled plug on MAF sensor: didn't make a difference
- removed plugs, let cylinders "air out" for 5 days in case they were flooded, cranked with injectors disconnected occasionally
- used timing light and degreed SuperDamper to confirm all 8 cylinders are getting spark at the right time
- used timing light, degreed damper, and TDC pointer installed by Blackstone to confirm cranking advance is 14 degrees BTDC

Summary

- ignition checks out OK - good and properly timed spark at the end of all 8 wires, and no sign of scatter
- fuel checks out OK - good injectors, good injector control signals from the PCM, and good fuel pressure in the rail
- engine sensors check out OK - no PCM codes
- compression checks out OK
- engine cranks steadily at 150 rpm
- PCM has correct power and ground on all 4 connectors

Got any other ideas?