daniel6718

iTrader: (36)

ive got a hummer thats in my shop that has a problem...start fine when cold but dies (sputters then dies) after about 10-15 minutes, half the time it will restart and die after 2-3 second sometimes it wont start at all

is has crank position sensor code..336 signal lost more than 8 seconds...it has had the crank position sensor replaced with a autozone one then a gm one still has the same problem

went through all data and checked it for 12v waited till it died then checked again still had correct voltage(kinda hard to tell because sometimes it restarts)


it says could be a reluctor wheel problem, ive never heard of a ls1 having that...(6.0) even so, it starts when cold...like possibly the spacing is wrong?

Doc

iTrader: (9)

I take it you have tried the re-learn? Checked the wires from the sensor to the pcm?

daniel6718

iTrader: (36)

from the wire to pcm i have ohm them they are fine...havent tried to relearn?

Doc

iTrader: (9)

Crank Position Relearn. With a tech II or aftermarket scantool?

daniel6718

iTrader: (36)

my scantool wont do it...i didnt think of the relearn although i read it on alldata...ill attempt it then go from there

daniel6718

iTrader: (36)

got someone bringing me a tech2 soon...quick question why does it need to relearn? i mean ive built motors done motor swaps ect and never had this problem...is there a reason?

Doc

iTrader: (9)

Generally when you mate up a "new" to the motor pcm, this re-learn will be required. I've seen some cases with vehicles with power/charging issues the pcm can "forget" the data and require a relearn. Usually ends up being a wiring issue... Has the vehicle ever been in an accident or since it's a hummer, submergered? Had a Z71 suburban come in recently that had been flogged in a mud pit of some sort as evidenced by the filthly engine bay- No start, nothing electrically. Pulled the pcm connectors off and the blue connector was water logged shorting everything out.

poconojoe

iTrader: (43)

Doc how is he going to do a relearn, if the motor isn't up to temp? I thought it had to at least 160 to start the relearn, is there a trick to get it to do it?

daniel6718

iTrader: (36)

no wreck not submerged...just cps went bad and replaced it...it starts and runs perfectly when cold...about 15 mins of idle it dies...had another truck pcm i was goana try but it didnt plug in...i tried moving every bit of the harness i could when it was cold and no change...i ohm the wires when it was hot and it was fine...

daniel6718

iTrader: (36)

did the relearn and that fixed it...thanks guys