88 Z51 C4 update

Bobzilla wrote: Here's a new pic from this morning. Yes, I tore down and rebuilt a SBC without the basic knowledge of how the cylinders are labeled. I am that stupid. The wires that I originally had on there were parts house wires that were 2 miles too long even thought they were supposedly spdific fit for an 88 Corvette.. To keep them from rubbing against places they shouldn't I had to get creative with my wire routing.

Can't see the pic, and I can't tell if you're joking or not. Was the cylinder number/firing order wrong?

In reply to Bobzilla:

Not sure I'd admit that on.. that other forum. :)

He says he's being sarcastic.

Bobzilla wrote: Here's a new pic from this morning. Yes, I tore down and rebuilt a SBC without the basic knowledge of how the cylinders are labeled. I am that stupid. The wires that I originally had on there were parts house wires that were 2 miles too long even thought they were supposedly spdific fit for an 88 Corvette.. To keep them from rubbing against places they shouldn't I had to get creative with my wire routing.

Hey, I understand you are frustrated, but you're the one with the car that won't run on all cylinders. We're just here trying to help. Try toning down on the snark. When it seems like you have covered everything, it might be the simplest of things that you overlooked because you weren't paying attention.

njansenv wrote: I'd pull the injector and fuel rails, and make sure the injectors are all firing properly. I know the LT1 injectors can be really problematic. Wet plugs doesn't necessarily mean there is enough fuel - if it's super "lean", it won't fire. I could be full of it: testing injectors is easy, move injectors around and see if the misfire moves. Of course, if you have a wiring problem to the injector, that requires a different test.

Per previous posts, already moved injectors and plugs. No change. L98 is different than LT1. LT1 is sequential port, L98 is batchfire.

tuna55 wrote:

Bobzilla wrote: Here's a new pic from this morning. Yes, I tore down and rebuilt a SBC without the basic knowledge of how the cylinders are labeled. I am that stupid. The wires that I originally had on there were parts house wires that were 2 miles too long even thought they were supposedly spdific fit for an 88 Corvette.. To keep them from rubbing against places they shouldn't I had to get creative with my wire routing.

Can't see the pic, and I can't tell if you're joking or not. Was the cylinder number/firing order wrong?

No, the cylinder numbering and wire routing was not incorrect.

Derp! Sarcasm doesn't always work on Al Gore's invention I gues.

I don't think this is your issue, but I'm not a fan of having the high voltage wires touching since it can lead to crosstalk.

Summary: 4-5-6 are dead. Good Compression Wet plugs Got spark no vacuum leaks. miss does not the injector or harness(not that determining this is easy a batchfire system)

Correct?

especially since I've sprayed them with water in the dark and gotten no errant sparks arcing out.

Sounds like you have 3 injectors firing out of sync. Where are the injector drivers located in the system? Does the ecm/pcm run the batch fire or something else? Is there anyway you can tell the injectors are firing when you have spark? Can you get a known "good" ecm to swap out and check the injectors with? Sorry i've got more questions than answers (absolutely none, except for the ecm/pcm swap)

ALL passenger injectors fire at hte same time, all drivers side injectors fire at the same time... this is called batch-fire. Is this thing on?

I HAVE PHYSICALLY SWAPPED INJECTORS, I HAVE PHYSICALLY SWAPPED INJECTOR PLUGS. THERE IS NO CHANGE. I HAVE CHANGED #2 AND #4 INJECTORS/PLUGS. I DID THE SAME THING WITH 6/8 AND 5/7. THERE IS NO CHANGE. THE GOOD CYLINDERS ARE STILL GOOD, THE DEAD ONE S ARE STILL DEAD.

tpwalsh wrote: Derp! Sarcasm doesn't always work on Al Gore's invention I gues. I don't think this is your issue, but I'm not a fan of having the high voltage wires touching since it can lead to crosstalk. Summary: 4-5-6 are dead. Good Compression Wet plugs Got spark no vacuum leaks. miss does not the injector or harness(not that determining this is easy a batchfire system) Correct?

Correct.

Let me try and summarize this, since we're all getting things confused:

4-5-6 are not firing (and presumably, you're absolutely sure of this)

Fuel injectors are batch fired

Fuel injectors have been switched with known good units from other cylinders

Plugs have been switched with known good units from other cylinders

Wires have been switched with known good units from other cylinders

Compression has been tested, 4-5-6 are OK

Haven't read about yet:

Valves have been seen opening and closing on 4-5-6 (valve cover off during cranking)

Plugs are wet with fuel?

Plugs checked for spark by the 'ground it against the block' method?

Exhaust ports/tubes clogged?

Intake ports/runner clogged?

(towel or something you used during assembly)

It only needs suck, squeeze, bang and blow. just keep thinking like a 5 year old put it together with a wooden hammer at those three cylinders and you have to be able to get it. It's not like a Citroen suspension issue or anything.

I replaced the intake gaskets, there were no obstructions. I have ....hang on, I'm just going to copy and paste from earlier in the thread...

Bobzilla wrote: OK, two weeks later, still fighting it. 4-5-6 are still no go. What I've done: Swapped injectors. Swapped injector wiring (no change, dead cylinders still dead, good cylinders still good) changed wires (new Accel custom fit wiring run to not touch anything) checked, rechecked and checked again firiing order readjusted the rockers checked for bent pushrods.( none bent} Measured valve openings (all matched) Changed plugs checked plugs changed the timing turned the dist 180* put in new 255lph fuel pump checked compression checked fuel pressure I'm pretty much out of options/ideas. I'm down to wondering if the cam is not installed correctly or.......

HERE.

sINCE THAT post I found a msassive intake leak. Pulled intake and resealed it and used better bolts to get a secure fit.

Bobzilla wrote:

Bobzilla wrote: OK, two weeks later, still fighting it. 4-5-6 are still no go. What I've done: Swapped injectors. Swapped injector wiring (no change, dead cylinders still dead, good cylinders still good) changed wires (new Accel custom fit wiring run to not touch anything) checked, rechecked and checked again firiing order readjusted the rockers checked for bent pushrods.( none bent} Measured valve openings (all matched) Changed plugs checked plugs changed the timing turned the dist 180* put in new 255lph fuel pump checked compression checked fuel pressure I'm pretty much out of options/ideas. I'm down to wondering if the cam is not installed correctly or.......

HERE. sINCE THAT post I found a msassive intake leak. Pulled intake and resealed it and used better bolts to get a secure fit.

From my list, that still leaves:

Valves have been seen opening and closing on 4-5-6 (valve cover off during cranking)

Plugs are wet with fuel?

Plugs checked for spark by the 'ground it against the block' method?

Exhaust ports/tubes clogged?

Drove the car into my place of employment to let our resident GM engine guy take a look at it and see what he can find. He's been following along this entire progject and he's just as stumped/curious as anyone.

At this point I have nothing left. No more tricks in my bag. No direction left to turn. No more patience. No more. My mental state can't handle it anymore.

tuna55 wrote:

Bobzilla wrote:

Bobzilla wrote: OK, two weeks later, still fighting it. 4-5-6 are still no go. What I've done: Swapped injectors. Swapped injector wiring (no change, dead cylinders still dead, good cylinders still good) changed wires (new Accel custom fit wiring run to not touch anything) checked, rechecked and checked again firiing order readjusted the rockers checked for bent pushrods.( none bent} Measured valve openings (all matched) Changed plugs checked plugs changed the timing turned the dist 180* put in new 255lph fuel pump checked compression checked fuel pressure I'm pretty much out of options/ideas. I'm down to wondering if the cam is not installed correctly or.......

HERE. sINCE THAT post I found a msassive intake leak. Pulled intake and resealed it and used better bolts to get a secure fit.

From my list, that still leaves: Valves have been seen opening and closing on 4-5-6 (valve cover off during cranking) measured all valve openings, been checked Plugs are wet with fuel? yes. from earlier in the thread, and later. Plugs checked for spark by the 'ground it against the block' method? yes, that's how I check for spark. Exhaust ports/tubes clogged? no obstructions on the exhaust.

answered.

Have you checked spark only during cranking, or did you also check at 2000 rpm and higher. Have you swapped distributors?

Spark has been checked running and cranking. There in both cases. I only have one distributor. Seemed rather silly to waste money on something that was working.

Late to the thread but did you check in the distributor cap for debris? Perhaps it's shorting inside the cap? That would still happen even with the distributor turned 180 degrees as you said earlier.

Yes. Cap looks new becaus it is.

What actually tells the injectors to fire Bob, and where does it take signals from? Is it in the main ECM, or is their an injector driver ECU, or??? I understand that they are bacth fire, but with you ruling everything possible to do with spark out, it has to be fuel. My thoughts are that the batch fueling is coming out wrong (hence you getting wet plugs for the 3 dead cylinders) and the SBC is running anyway.

In reply to Javelin: What he said...

Does it run on all 8 if you run it on starter fluid?

IIRC, the ignition module tells the ECU where the dist is so the ECU can fire the correct bank of injectors.so essentially, the pickup coil/ign module tell the ECU when it needs to fire the injectors.