ive done searched the forums but couldnt find anything exactly like what im experiencing. this is completely random 110%. ill jump in fire it up everything is great get to the store or gas station fill up or get groceries come back out go to crank and just keeps cranking no start. keep getting evap system high flow code once in a while. but regardless thing will crank and crank no start. now i go to crank it and feather the accelerator and it will.sputter for a slight second then start right up run smooth as if it were new. its bad ive been a mechanic for 12 years and im freakin lost. cleaned maf checked maf connections changed air filter checked fuel pressure all good. im lost. i wouldnt think evap control high flow wouldnt have much to do with this issue although i could be wrong. anyone seen or heard of this before? like i said some days it does it some days it doesnt. its throwin me for a loop. ive owned many vehicled with 5.3L some with over 250k miles never seen this issue. almost forgot. no cel either. hook up scantool and no codes even stored. i thought maybe passlock but wait 10 mins and still the same not to mention no passlock light. only thng thatll get it going is feathering the accelerator. tps sensor maybe? coolant temp sensor maybe thinking its too cold and overfueling. just aint makin sense

 

One of our 2008 alphas was doing the same thing and despite the passlock light not being lit solid it ended up being the ignition module (passlock). Once replaced it fired right up every time. Its a cheap easy part to swap and just know its not the issue.

 

I would try jiggling the connector @ the TB, then try jiggling the connection @ the pedal.

 

Pedal assembly or Passlock most likely. Both are known to fail with irritating frequency.

 

Never heard of passlock cranking, just dead, no noise when you turn the key.

 

Me either until this past winter we had one alpha and one 5cyl both crank but not start only thing that we changed was passlock module and they both started up no issue and have been fine for months.

 

Ah yes the great H3 Guru Tainter hasn't seen it therefore it cannot not exist.

 

so its only after fueling. every time i fuel it get in it does it. freakin weird. outside of that works perfect. put fuel in it. bam crank but no start till accelerator is feathered

 

flush the tank and get a locking gas cap.

 

Thanks atvspeed, first time hearing of this happening.