Ls3 swap wont crank and backfires.
10-31-2015, 05:24 PM
#1
Ls3 swap wont crank and backfires. Ok heres the background. I bought a used l92 block and had it completely rebuild except for the rods and crank. Crank reluctor was swapped to 24x and tack welded. It has tick street heat stage 2 cam and pnp heads by greg goods. Im using my 411 pcm and was reflashed.
The issue is that car will not start and it backfires on the intake.
Check:
Fuel pressure. Ok
Sparks. Ok
Signals from cam and crank sensors . Ok
Cam gear was 180 degrees off. Fixed it and still no start.
The only thing left to check without dropping the pan is the reluctor wheel to make sure he installed the wheel right since he tack welded it. The engine builder did not have the tool to replaced the wheel so i sent it to lamar walden to do the wheel swap. Could the engine builder improperly installed the crankshaft and cost the relctor wheel to be off? Or is lamar waldens error?
Any help or suggestions?
The issue is that car will not start and it backfires on the intake.
Check:
Fuel pressure. Ok
Sparks. Ok
Signals from cam and crank sensors . Ok
Cam gear was 180 degrees off. Fixed it and still no start.
The only thing left to check without dropping the pan is the reluctor wheel to make sure he installed the wheel right since he tack welded it. The engine builder did not have the tool to replaced the wheel so i sent it to lamar walden to do the wheel swap. Could the engine builder improperly installed the crankshaft and cost the relctor wheel to be off? Or is lamar waldens error?
Any help or suggestions?
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11-02-2015, 11:12 PM
#9
TECH Resident
Ouch, The spec on the reluctor wheel is something like +/-.010 runout front to back. That needs to be right, but the big question, is it timed right when it was welded on the crank? It has to be degreed to the crank or the timing will be off. I agree with 00ss, probably have bent valves. Compression check needed. Those little details can cause big problems.
11-02-2015, 11:21 PM
#10
TECH Resident
https://ls1tech.com/forums/generatio...tor-wheel.html
Check this post. It shows a reluctor alignment tool. If you do not use something like this, your timing is probably not right.
Check this post. It shows a reluctor alignment tool. If you do not use something like this, your timing is probably not right.
11-03-2015, 01:46 PM
#12
Ouch, The spec on the reluctor wheel is something like +/-.010 runout front to back. That needs to be right, but the big question, is it timed right when it was welded on the crank? It has to be degreed to the crank or the timing will be off. I agree with 00ss, probably have bent valves. Compression check needed. Those little details can cause big problems.
11-03-2015, 01:47 PM
#13
https://ls1tech.com/forums/generatio...tor-wheel.html
Check this post. It shows a reluctor alignment tool. If you do not use something like this, your timing is probably not right.
Check this post. It shows a reluctor alignment tool. If you do not use something like this, your timing is probably not right.
02-20-2016, 10:11 AM
#16
Ok. So updates:
Brought the car to abother mechanic. He tore down the engine, changed the crank to 24x reluctor wheel. Inspect everything and adjust clearances. Wire everything up and it still wont crank. Wtf!!?
Im this close to part everything out...!
02-20-2016, 11:11 AM
#17
How did you determine this? The gear will be pointed at 6 and 12 on the compression stroke and 12 and 12 on the exhaust stroke.
The cam turns at 1/2 speed so if aligned at 12 and 6 and you turn the crankshaft one revolution they would be aligned at 12 and 12. So I don't think that was a problem, You just thought it was.
So no bent valves from misalignment.
The cam turns at 1/2 speed so if aligned at 12 and 6 and you turn the crankshaft one revolution they would be aligned at 12 and 12. So I don't think that was a problem, You just thought it was.
So no bent valves from misalignment.
