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LT1-LT4 Modifications 1993-97 Gen II Small Block V8

24x LT1 not starting

 
Old 01-13-2019, 10:17 PM
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Default 24x LT1 not starting

...grrr.

So she will crank but no spark, no injector pulse. Cranks like a champ, but doesnt pop or otherwise even try to start.

So far, ive checked:
-correct crank position sensor, gapped at .030" to the reluctor. 2nd design EFI ring (single row)
-power and grounds at PCM.
-all pinouts correct to the sensors.
-fuel pressure @ 50 psi during prime, drops to 35 afterwards.
-all sensors connected
-ring is damn near centered in the sensor hole.

Im getting no RPM on the tach while cranking.

I cannot yet hook up a scan tool. I still have the OBD 1 connector in the car, planning on pulling the entire interior in the next couple of weeks to do a bunch of interior work, to include replacing the dash harness.

Last time I had this problem, it was a bad tune that caused a no start...starting to seem like that may be the problem again.

I read that EFI has instructions to measure the distance between the ring and the block. Of course, I find out now that its all back together...however, I can probably still do it pretty easy depending on how its measured (2 piece timing cover).

It's a 355 '94 Z. Harness is a repinned '95 harness. Anything simple I might have overlooked before going further into this?
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Old 01-14-2019, 07:46 AM
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I would get a scan tool first and verify you have cam/crank signals before chasing ghosts.
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Old 01-14-2019, 08:15 AM
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If I remember correctly, the ckp signal is the only one required for the engine to send spark and injector pulse, correct? Im going to try to rig something for now to hook up the scan tool so I can see what its doing...

Im going to call EFI today as well and get their thoughts on this. You would think by merely pulling off the old reluctor that worked and replacing it with another that it should read...
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Old 01-14-2019, 08:53 AM
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Another easy test is to verify you have power at coil packs and at injectors. (grounds check would help too)
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Old 01-14-2019, 09:24 AM
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I do. Got all my power and grounds and verified the pinout and circuit integrity. No dice.
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Old 01-15-2019, 09:11 AM
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Did you check the firing order? This could be an issue too!
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Old 01-15-2019, 10:02 AM
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Its wired correctly for the LT1, verified pin by pin with BP's kit.

Even if it were that far off, it should at least pop or something. It doesnt even TRY to start, other than spinning over like a champ.
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Old 01-15-2019, 07:55 PM
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Im getting no RPM on the tach while cranking.
This might be your problem. Check the wiring to your CKP sensor.. I had the same problem and had to repin the CKP sensor connector on the harness.

Either that or your gap between the 24x reluctor and sensor is not correct
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Old 01-15-2019, 09:38 PM
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I did a check on the ckp sensor. I couldnt get it to pulse even if I removed the sensor and tried to pass it over a ground. Checked the signal wire for a pulse, couldnt get anything either.

Got another sensor to try and of course, the battery is dead. Wont hold a charge. Time to warranty it out and try again tomorrow.

The new,sensor would trigger the pump whenever it was plugged in and unplugged, something the old one wouldnt do. Im crossing my fingers here it was just a bad sensor.

Currently the gap is set at .034".
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