Explosion, now no start.

[vikenabm]

A bit stumped, frustrated, would love help making a diagnostic task list to get my car started again. MKIII turbo swap into 1989 NA body, ran okay but was tracking down high pressure boost leaks with custom piping to the new intercooler. IN the process i carelessly set the timing wrong, or I think I did. It started with difficulty, ran horribly with a lot of fuel smell, wouldn't rev, and when i opened the throttle it exploded, loudly, and stopped abruptly. Restarted the same way, then did the same thing. Hasn't started since then. found CPS timing badly off but intake cam was still up when crank was at TDC. Turns over, but no sense of any ignition happening. pulling injector resistor connector doesn't affect the turn over sound at all.

Fuel: Fuel pressure is good, tried anywhere from 30psi to 45 with no luck.

Spark: Iridium plugs damp but not damaged, except number 6 plug was dry, also undamaged. cleaned them, checked resistances of plugs, wires, injectors, injector resistors. observed good sequential sparking in all 6 plugs mounted in a threaded metal holder. Engine grounds are all retapped and clean.

Compression: about 155psi in all cylinders.

Turbo impeller turns freely without play.

New RC injectors were working, but i put a new heat shrink on all of them. Don't know that I have any reference on what polarity they need, so if that matters please let me know. worried about injectors stuck open.

Questions:
is that explosion "detonation"? SOunded like the sound of a block on the bench being static pressure tested and having the valve popped open with a mallet to seat it. that type of loud pop but much louder resonating through the exhaust system.
What else should I test?

Thanks!

Mods:

K&N filter to Lexus AFM | 660cc RC | Holley 255 LPM FP | JE/Eagle internals | 2.5" hard pipes | Toyo high flow intercooler| S Sanchez ported head | 1.2mm beaded MHG | compression 9:1 w/0.5 overbore | modified ex mani | CXR 3" full exhaust | Slotted/drilled rotors |New WG spring @12psi w/ dual switching man boost | Colt Mild perf. Cams | Bosch BOV | XTD clutch | Tokico Illumina w/TEMS | ES bushings | 18" Pirelli P-zeros | Manual AFPR

[vikenabm]

Wow. Kind of quiet here. Is it always like this? Anyway, in case anyone reads this, yesterday I pulled the turbo - perfectly good rebuilt stock turbo with no sign of damage. Then while it was off I thought I'd do a leakdown test for boost leaks. Got pressurized to 60psi and found slow leakage from multiple places, greatest was from the gasket between the upper and lower intake manifolds, so I separated them slightly, painted some copper RTV from a spray can in there, and resealed with significant improvement. Then various other slow leaks showed up that didn't seem worth chasing, since it obviously was sealing sufficiently that even at 30psi it wouldn't leak enough to make a big difference.

checked cam timing, both set to stock TDC.

checked all the voltmeter tests you can do without the engine cranking or starting, all were ok, except EFI main relay was 1v below battery voltage, but still within specs with a charged battery. Will check connections and ground there and clean that up.

So that's it. For want of a better idea, I guess I'll put the turbo back on. and try starting it again.

I'm thinking maybe the problem is lack of fuel, for lack of a better idea. Spark and compression and timing all were checked and are pretty easy to observe, though I could stand to double check he igniter circuit to coil wiring. Would like a more direct test of the new RC 650 injectors to be sure they are opening and spraying correctly when installed in the engine, trying to think of how I can be absolutely sure they are operating ok.

I'd like to triple check everything possible before trying to start again. I'm beginning to consider swapping the ECU if I don't come up with a better idea soon. That will involve using an automatic trans ECU and making changes in wiring internally so it works with the manual trans, at least to start it. that's a bit of a PITA, so I was hoping to avoid it.

That's it: no real smoking gun found. Feeling like i'm missing something obvious here. Would love to hear from another real live supra owner out there.

[cre]

This isn't the busiest of Supra sites, no. I've been pretty busy and haven't had a chance to really read through it but I've been meaning to make some time to go through your post and see what I can come up with.

I'll look it all over tomorrow (it's very late here now) and let you know if I can think of anything that's missing. One issue that comes up from time to time it the CPS being clocked 180? off (refer to the FAQ thread on timing to make sure that one is right). And no, there is not proper polarity for the RC injectors, just a simple coil in there so nothing to worry about unless they're not wired in the proper order.

[vikenabm]

Originally Posted by cre

This isn't the busiest of Supra sites, no. I've been pretty busy and haven't had a chance to really read through it but I've been meaning to make some time to go through your post and see what I can come up with.

I'll look it all over tomorrow (it's very late here now) and let you know if I can think of anything that's missing. One issue that comes up from time to time it the CPS being clocked 180? off (refer to the FAQ thread on timing to make sure that one is right). And no, there is not proper polarity for the RC injectors, just a simple coil in there so nothing to worry about unless they're not wired in the proper order.

Thanks for your kind and generous attention. I do appreciate it. I dont know that timing was off by any specific amount. I know it was way off, and I think I must have forgotten to set the crank to tdc. I know the cam timing was correct and still is.

[cre]

The cam's timing is entirely dependant on the crank's position. Timing is not set in any way if all of the components are not set at a matching degree. The distributor, cams and crank ALL must be at zero or your efforts are wasted. First go and ensure that the mechanical timing is properly set, then set the ignition advance (as detailed in the TSRM). Report back with any additional findings.

EDIT:
Ok, I re-read your post and am a little confused I suppose. Go over the thread linked to below and make sure everything is 100% correctly aligned. If you've removed the cam gears at any point make sure the dowels were installed in the center hole on each cam and likewise on the gears. If you're running adjustable cams dial them to 0? initially.

http://www.toyota-supra.info/forums/...-e-timing.html

[vikenabm]

Originally Posted by cre

... Ok, I re-read your post and am a little confused I suppose. Go over the thread linked to below and make sure everything is 100% correctly aligned. If you've removed the cam gears at any point make sure the dowels were installed in the center hole on each cam and likewise on the gears. If you're running adjustable cams dial them to 0? initially.

Got this but apparently my response was swallowed by the Verizon network.

Rechecked timing this week. it was set according to the exact procedure you linked to, and cam matchmarks and crank mark are still aligned correctly. The pictures are very nice and clear, and I've set the timing many times before. Unfortunately, the timing advance can't be set without the engine running, but I can approximate it with the engine cranking using a timing gun. I think that type of electrical test for timing would be a good reality check anyway and I hope that will be sufficient proof without pulling the CPS again. The CPS was the last thing I had pulled and reset - and done carefully - before posting the problem on here. The timing gears were removed when rebuilding, They are the stock gears, so position is set by the fit of the gear on the cams.

I will
1) verify that the cam lobes are aligned as expected with the match marks, just to be extra certain, on Saturday.
2)Will check each cylinder for spark with inductive timing gun to verify correct sequence as wiring from igniter to coils was extended and soldered due to fraying and breakage.
3) remove CPS cover and verify armature alignment with crank and cam timing marks at TDC.

I'll let you know when this is completed.

Thanks.