Duramax Compression After Gas

[diesel71]

if you used a good respectable company for the rebuilds then YES the numbers are valid. if they were real cheap then the numbers are from the first time they were flow tested.

[Glide]

I used rebuilt injectors from a non GM source. I entered the calibration numbers that were on the injectors and learned them to the ECM and GPCM. Do you think that the numbers are still valid being that they are rebuilt ?

That's a good question,I would doubt it.I've only used reman injectors on one duramax( a vin 1 ),had my first bad result working on one of these ever.Now I flat refuse the job if the customer doesn't want to use OEM parts.
The local dealer gives me good enough prices that reman **** isn't that much cheaper anyway.

[Witsend]

I used rebuilt injectors from a non GM source. I entered the calibration numbers that were on the injectors and learned them to the ECM and GPCM. Do you think that the numbers are still valid being that they are rebuilt ?
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Doubt most Diesel owners care about a little black smoke on WOT especially if in front of a Prius, as long as it don't have CEL on, passes inspection and delivers decent mileage on par of what it had before

[greasybob]

I used rebuilt injectors from a non GM source. I entered the calibration numbers that were on the injectors and learned them to the ECM and GPCM. Do you think that the numbers are still valid being that they are rebuilt ?

[Witsend]

A new HP pump and injectors and it's a runner !!!! Finally got the pieces to put it back together. The only thing to pay attention to if you get a Dura Max that had gas in it is you'll get some engine knock and loping for the first few minutes after starting. I'm attributing this to carbon build up in the cylinder causing some detonation problems (misfires). Took it slow down the road for the first test drive and it all cleared up after a mile or so.
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Bob You are the Diesel man , gonna have to change your name to Grieselbub

[greasybob]

A new HP pump and injectors and it's a runner !!!! Finally got the pieces to put it back together. The only thing to pay attention to if you get a Dura Max that had gas in it is you'll get some engine knock and loping for the first few minutes after starting. I'm attributing this to carbon build up in the cylinder causing some detonation problems (misfires). Took it slow down the road for the first test drive and it all cleared up after a mile or so.

[Witsend]

I'd have to agree with that. Although diesels will run on a diesel-gas mix with straight gas in the pump and injectors it's like running an engine with no oil. It may not be obvious but count on there having been damage done.

I personally doubt the engine itself has issues.
Yesterday 07:32 PM

I guess the safest quickest bet would be to replace the whole ball of wax at the time of flushing everything out and not have to deal with additional time it would take to get running right on straight diesel and to find out if the injection control pressure confirms the pump is trashed or not.If it were my truck , I would ask if you could pour a couple ounces of Krex or something similar into the filter housing to supplement additional system lubricity as the diesel works it's way through. Maybe even a little Bio Diesel sourced from KFC grease trap,if it saves me dropping another several grand LOL

[GypsyR]

I'd have to agree with that. Although diesels will run on a diesel-gas mix with straight gas in the pump and injectors it's like running an engine with no oil. It may not be obvious but count on there having been damage done.

I personally doubt the engine itself has issues.

[diesel71]

new pump and injectors is the right thing to do. it will eventually fail if you just flush. they ran it until it wouldn't run anymore which means the gas has flushed what little lubricity the diesel fuel had out of the pump and sticks.

[Witsend]

Had a 13 GMC Sierra 2500 with a Duramax towed in. They ran gasoline through it till it didn't run no more so I was told. The engine is already partially stripped down. Where to start, is it damaged ? First i did a relative compression test with the amp probe. Looked ok, at least all the cylinders are even, but maybe they're evenly low ? I have a diesel compression gauge but no Duramax fitting. So I took a glow plug and cut the ends off and then drilled out the center. Then I welded a fitting on the end so I could connect it to a pressure transducer. Not perfect but I tested one cylinder and it worked ok. Pressure a little under 400 psi. I think I'll go with a new high pressure pump and new injectors, flush everything out and and see what we get.

If it ran as long as it did with gasoline , What do you think would happen if you just flushed the tank and supply side of gasoline, disabled the glow plugs and just tried to crank and run out what remains of the small amount of gasoline still left in the High pressure pump, and the fuel injectors?

[SnapOnKid]

Nice work on being creative!!!

You get an A for effort today buddy.

Let us know how it turns out.

[Crusty]

Jury rigging some sort of fitting to get a pressure reading..... Done that many a time over the years.
Ya do whatcha gotta do-!!
Good work Bob, but nothing I wouldn't expect from you anyway-!!

[greasybob]

Had a 13 GMC Sierra 2500 with a Duramax towed in. They ran gasoline through it till it didn't run no more so I was told. The engine is already partially stripped down. Where to start, is it damaged ? First i did a relative compression test with the amp probe. Looked ok, at least all the cylinders are even, but maybe they're evenly low ? I have a diesel compression gauge but no Duramax fitting. So I took a glow plug and cut the ends off and then drilled out the center. Then I welded a fitting on the end so I could connect it to a pressure transducer. Not perfect but I tested one cylinder and it worked ok. Pressure a little under 400 psi. I think I'll go with a new high pressure pump and new injectors, flush everything out and and see what we get.