LB7 Engine Troubles

[Timthecarman2004]

Well here goes. On a recent build for a 2001 2500 dmax. This truck is bone stock. Never had a chip on it. No EFI Live, stock intake, stock injectors.

A new motor was built using a Stock LBZ shortblock with the reluctor wheel modified to accept the LB7 crank sensor. New heads, head gaskets, nozzels, turbo. Everything, I mean Everything was LB7 stuff from the old motor except the; Block, crank, rods, pistons, can, front gears, front cover, rear cover, dampner, and flexplate.

The engine starts up perfect. Sounds perfect, great oil pressure, no knocking. Truck is test driven, and sounds like it has fuel knock.

Using the Tech2 the main injection timing drops to 0* when accelerating. This is when the motor becomes noisy. If the truck is warmed up (190*) the timing at idle is -4*.

We thought that the front cover might have been giving some problems so had the old front cove, reluctor wheel and gear, waterpump, and old sensor spacer installed. This did not change a thing. Still sounds great at idle, but hard on the throttle sounds like the timing is way a little off.

Anyone have any ideas.

P.S. when the clattering starts it may or may not throw a P0236 code for the turbo. It is intermittent.

Any and all help would be greatly appreciated as Mike wants his truck back.

[TheBac]

OK, I've helped with Dmax builds before, so I am in no way an expert here.

That being said, could the cam be the culprit? Maybe its not timed correctly?

That in no way is a knock on your skills Tim. Just trying to toss out ideas.

[Ridge_Runner_Diesel]

Are you using the 2001 OS ???

Stock timing table is 0 for most of the map when driving,

Idle at -4 TDC is correct as well.

Pilot injection shuts off at 2800/70 mm3 of fuel.

It could be a bad injector, injector knocks are a PITA,

Try some 2 stroke oil in it.

Tony

[Nick]

I had something similar happen with my truck, thought was injectors. Did the injectors and it didn't help. Timing just didn't sound right (stock tune).

I put some two stroke in it and it cleared up (two quarts to a 25 gallon tank). It's never been back. I think maybe it was a bad tank of fuel... who knows.

It's worth a shot. :)

Nick

[Timthecarman2004]

OK, I've helped with Dmax builds before, so I am in no way an expert here.

That being said, could the cam be the culprit? Maybe its not timed correctly?

That in no way is a knock on your skills Tim. Just trying to toss out ideas.


No offense taken. Any ideas are appreciated. I had Reid Graham check that when they replaced the front cover with the LB7 one. Everything was lined up perfect.

Are you using the 2001 OS ???

Stock timing table is 0 for most of the map when driving,

Idle at -4 TDC is correct as well.

Pilot injection shuts off at 2800/70 mm3 of fuel.

It could be a bad injector, injector knocks are a PITA,

Try some 2 stroke oil in it.

Tony

Tony as always you are a gentleman. Thanks for the information. I just called them and told them to throw in a couple of quarts into the fuel. Everything that you wrote is what the tech 2 was showing. I think that they are trying a different crank sensor today. What other sensors would cause the engine to have timing rattle???

I had something similar happen with my truck, thought was injectors. Did the injectors and it didn't help. Timing just didn't sound right (stock tune).

I put some two stroke in it and it cleared up (two quarts to a 25 gallon tank). It's never been back. I think maybe it was a bad tank of fuel... who knows.

It's worth a shot. :)

Nick


Nick thanks for the responce. We will see if this helps as they are going to try it today. I will post and let everyone know what happens.

Thanks
Tim

[Ridge_Runner_Diesel]

Check the ECT sensor, there is an add on table for additional timing with a multiplier for cold weather. It will add timing if it thinks it is a cold engine, like 40 or less F.

Also check the baro sensor, it adds timing if it thinks it is in higher elevations.

:)

It could be fuel pressure as well, the FRPCV could be screwed.

If all else fails , this is a no going back either, flash a 2002 OS into it or swap it with a 2002 ECM and see if things are happy.

The 2001 OS suck IMHO, I update every 2001 truck to the 2002 OS/15186006.

;)

[Timthecarman2004]

Tony, I have a bench harness coming, and I will be flashing the ECM if the ol 2 cycle stuff doesn't work. What should the BARO read for Texas??? It is funny how it sometimes throws a boost code. I think that it was a P0236 code. I will have to look at my notes.

Thanks again Tony.
:thumb:

Tim Hecker
St. Joseph Diesel Inc.

[Ridge_Runner_Diesel]

If the boost is out of range for any reason for a period of time it sets a code.

It could be a sensor, maybe not.

I know that if you decide to flash the OS to a 2002 you will need 15186006, I can send you one if needed, I just need to know if it is a Federal or CA truck emmissions and a long or short bed for the tank calibration.

Tony

[Timthecarman2004]

I haven't personally seen the truck so I will get the specs from Morris at Reid Graham. Thanks again for the help Tony.

[Nick]

After talking with Mike quite a bit, he decided he wanted to try to tune out the knock in the engine. So I inherited this one from Tim (thanks for all of the info by the way Tim - very cooperative and helpful) :Handshake:.

At this point it seems to be a timing knock from a false timing addition based on coolant temperature. I need to have him send me scan files to verify this, but based on his results from the tunes I've sent him, I think we're on to something. He says the truck picked up 7 mph on his test track (same stock tune otherwise).

More results as things materialize.

Nick

[moduramaxdad]

i had a coolant sensor that had a short in it and it would intermentantly turn my intake heater on and it sounded terrible. knocked and rattled like it was on the verge of coming apart.

[Timthecarman2004]

That is almost what Mike is experiencing. Seems that Nick is on to something. I wish that I could be there helping, but these past few weeks have been really hard trying to get the wedding things finished up.

[RickDLance]

Wedding?

[Kevin G]

Ask him what he wanted to do at the so called "bachelor party"....:lol:
It would've been the most viewed video on you tube for sure, but they wouldn't let him do it.:thumb:

[Ridge_Runner_Diesel]

Check the ECT sensor, there is an add on table for additional timing with a multiplier for cold weather. It will add timing if it thinks it is a cold engine, like 40 or less F.

Also check the baro sensor, it adds timing if it thinks it is in higher elevations.

:)

It could be fuel pressure as well, the FRPCV could be screwed.

If all else fails , this is a no going back either, flash a 2002 OS into it or swap it with a 2002 ECM and see if things are happy.

The 2001 OS suck IMHO, I update every 2001 truck to the 2002 OS/15186006.

;)

After talking with Mike quite a bit, he decided he wanted to try to tune out the knock in the engine. So I inherited this one from Tim (thanks for all of the info by the way Tim - very cooperative and helpful) :Handshake:.

At this point it seems to be a timing knock from a false timing addition based on coolant temperature. I need to have him send me scan files to verify this, but based on his results from the tunes I've sent him, I think we're on to something. He says the truck picked up 7 mph on his test track (same stock tune otherwise).

More results as things materialize.

Nick

That is almost what Mike is experiencing. Seems that Nick is on to something. I wish that I could be there helping, but these past few weeks have been really hard trying to get the wedding things finished up.

i had a coolant sensor that had a short in it and it would intermentantly turn my intake heater on and it sounded terrible. knocked and rattled like it was on the verge of coming apart.


Glad I mentioned something about the coolant sensor.

:thumb:

[JMDuramaxLB7]

Ask him what he wanted to do at the so called "bachelor party"....:lol:
It would've been the most viewed video on you tube for sure, but they wouldn't let him do it.:thumb:



Thata for sure LOL...