L31 5.7 Vortec Swap Wont start?!
02-07-2015, 04:39 PM
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L31 5.7 Vortec Swap Wont start?! Hey guys, I need some help diagnosing my problem. I swapped my lower km rebuit l31 (previously carbed) into a 1997 GMC Safari AWD and converted it back to factory l31 fuel injection. I am having troubles getting it to run. It either starts and stalls out, or wont start at all and just sputters.
I'm pretty sure it has a double roller timing set, which I've read is impossible to fit with the reluctor ring, I am positive it has a reluctor ring and is sending a signal to the computer.
Motor is stock aside from mild cam, comp springs and double roller timing set.
Ive replaced the injectors to the updated mini injector style and replaced the whole distributor assembly, also has new o2 sensors.
It has spark, fuel and compression but doesn't usually start. It is in time enough to start (quadruple checked).
After trying to get it running and trying to diagnose all day, the oil has a lot of gas in it.
I have a blackbox pcm base tuned by blackbear performance for my specific application. Could i have gotten a bad pcm or tune?
Any ideas are appreciated as I am completely stumped.
I'm pretty sure it has a double roller timing set, which I've read is impossible to fit with the reluctor ring, I am positive it has a reluctor ring and is sending a signal to the computer.
Motor is stock aside from mild cam, comp springs and double roller timing set.
Ive replaced the injectors to the updated mini injector style and replaced the whole distributor assembly, also has new o2 sensors.
It has spark, fuel and compression but doesn't usually start. It is in time enough to start (quadruple checked).
After trying to get it running and trying to diagnose all day, the oil has a lot of gas in it.
I have a blackbox pcm base tuned by blackbear performance for my specific application. Could i have gotten a bad pcm or tune?
Any ideas are appreciated as I am completely stumped.
02-07-2015, 07:18 PM
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I will try that. There is a ckp relearn code and a code for the dist and crank being out of sync ( from me adjusting the distributor). When it would start (but run rough or stall out) before I would also get codes for too high of an input voltage on the map sensor and the tps sensor. There has been over 5 volts when I tested those but hasn't gone over 6 volts.
02-09-2015, 12:06 AM
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Unplugged the cam sensor plug. It fired up but died immediately. Then wouldn't restart just like before. It seems the longer it sits the closer to starting normally it sounds. Distributor seems to be clocked properly according to the mark on the balancer. (Its not out 180°, I checked)
02-22-2015, 04:50 PM
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Well I managed to get it running, must have been a battery issue somehow. It idles just below 2000rpm with no load. I will attach pictures of the datastream on the scan tool.
The DTCs are P1336 and p1345. Do any of the reading look out of the ordinary to you guys? I will look for vacuum leaks.
The DTCs are P1336 and p1345. Do any of the reading look out of the ordinary to you guys? I will look for vacuum leaks.
Last edited by 95stro; 02-22-2015 at 04:51 PM. Reason: grammar
