moes04silverado

iTrader: (2)

I've exhausted my options to no end on why I can get this truck to run... a little history.

Truck is a 2004 Silverado

Built a 370 LQ4 last year, got it in the truck last August with a tune from Nelson; everything ran great. Ran it most of this summer as well and everything ran great. Decided to get a dyno tune and after the new tune it ran great. About a month or so ago I was driving it in western new york and it started acting up (150+ miles from home) So I checkd codes and the only thing at the time was P0894, so i figured the converter finally gave way or the fluid need changed, so I drove it the rest of the way home. Got home and changed the trans fluid inspected what I could with the pan off (new filter also) put everything back together and now its throwing the p315, p0336 code, so no big deal ill just replace the cranksensor and get a CASErelearn right. Well I tried the relearn and no luck. The weird thing is if I let the truck sit for days and go start it, it fires right up, the minute I put it to gear, it falls apart. The day we tried the relearn it wouldnt even stay running for 5 seconds. And for the record, the new motor has 47XX miles on it...

Any idea boys? The only thing I can figure right now it that the senor wires are getting interference from something. Now it could be anything since I moved/re routed all the wires, ECM and main fuse location to under the center console, which to trace the sensor wire back isnt an easy task at this point but still needs to be done. The sensor wiring runs on top of the trans right up through the floor right below the console itself. The only wires that are near it is the pinkish wire that is for the starter, which really only has power when you go to start it, i thought.

As for the thought orgionally of the conveter or the trans, I dont think there is anything wrong with either, when I was driving it home, it still shifted perfectly fine no hard shift what so ever, just didnt have any power to get to highway speeds, oh and in 150+/- miles it used a full tank of fuel...

I think thats about all the information that I have

Please help

moes04silverado

iTrader: (2)

Ok a bit more information;

First i started it right up and it sat and idled perfectly fine, no hicups, nothing... turn key off, check codes, p0315,p0336! how can it idle properly and still throw those two codes... so clear codes, try to restart, it fires then falls on its face..................

i traced the crank senor wire back to the ecu, no cuts no sign of dismanglement. I cleaned the connector with electric cleaner and re connected... same issue.... so disconnected crank sensor, try to start....just rolls, no fire (like it should). So crank sensor is working....tried the same with cam sensor, when diconnected no start...re connected starts then falls apart....

hmmmm compression check.... 175-180 psi

took crank sensor out and felt for the reluc. wheel for movement....nothing...

So I am lost... any feedback

Gordy M

iTrader: (2)

This is a long shot. Is it possible you swapped PCM's and received one from a 1997-2004 Corvette? When the vettes had problems with column lock, they did a segment A change. If the battery started to wear out it would cause the column lock/ignition cutoff to occur. The trucks use a different column lock software and that would have changed with tune, but the segment A is a firmware change and would stay with the PCM. Try this, disconnect the battery, but a VOM on it and see if the battery is 12.5V or higher. The fuel cutoff occurs if the battery does not have 12.5V the cars would start and idle perfectly but die as soon as you reached 2 mph.

moes04silverado

iTrader: (2)

i like that thought, but I have to different PCM both from Nelson one that has a their tune on it and another one that has a custom dyno tune, i would be one unlucky person if i had two PCMs with that. But it is possible and I have not had very good luck as of late..

moes04silverado

iTrader: (2)

well i put the original crank sensor back in and got it to fire, and drive even! But its still got a huge miss somewhere. Still showing p0315,p0336 codes also. So I might send it back to my tuner and have him re-tune it. Im thinking it lost the timing between the crank and cam sensor somehow? i dont know

07 vmax

not to steal your thread or anything but im having similiar issues with my truck as well i just got a tune from nelson and installed it, did the security relearn and it just rolls and rolls but never really seems to fire sometimes it acts like its going to but never does and i havent done the crank position sensor relearn ? could that keep it from ever starting ? and where is the crank sensor and cam sensor located?

07 vmax

and im also getting the p0315 along with about 9 other codes

moes04silverado

iTrader: (2)

your not stealing, we all here to help each other!

The crank sensor is located on the pass side of the engine block behind the started.

The cam sensor is on the top back of the engine block behind the intake/valley cover.

If your getting the P0315 code your in a simualr postion that I am. It needs a crank relearn which has to be done with tunning software.

mecanicman

Have you tried checking the crankshaft endplay? A ballooned converter can put excess pressure on crank knocking out thrust bearings. This allows the crank to travel farther then it should and the relutor with it. Runs fine as long reluctor stays in place, when the crank shifts, not so much. Endplay spec is 0.0015-0.0078

moes04silverado

iTrader: (2)

hmmm, sounds like i might have a winner, how do i check the endplay? and i wouldnt doubt that the conveter has ballooned, its not a great conveter i paid a good amount for it, but its not the best - and it was acting up.. im not sure what causes it to balloon, but it very first acted like the conveter was locked up all the time...like when i drove it from New York....

makes sense - if there is excess end play, do i then have to tear to motor down again and replace bearings and seals and such? Or is it just a change in converters that will solve the end play (if its ballooned)

good thing the converter is easy to change!