Opinions on injector commands and balancing rates

[truck_n]

All of you peple that take part in this TDP forum have been a great help with my education on the Duramax. I hope I'm not wearing my welcome out, but I could use some help. I have the printouts from my dianostics and I need a knowledgeable second opinion. My '01 Duramax/Alli is at the dealer now. Problem: blue smoke at idle. 1st readout was fuel rail pressure 64.9 MPa with a desired pressure of 42.0 MPa. injector commands were .29ms -.31ms through all 8, balancing rate was 0.0 mm3 on all 8. trouble code was P0089. They replaced the fuel pressure regulator module, it's still smoking! They did a 2nd diagnostic. result was: Fuel rail pressure of 39.1MPa with a desired pressure of 40.0. injector commands and balancing rates were:
# 1 .08 ms, -3.4 mm3
# 3 .23 ms, -2.5 mm3
# 5 .41 ms, 2.9 mm3
# 7 .43 ms, 4.0 mm3
# 2 .26 ms, -1.8 mm3
# 4 .40 ms, 2.7 mm3
# 6 .31 ms, -0.5 mm3
# 8 .29 ms, -1.2 mm3
They want me to change all 8 injectors. The injectors are only 60,000 miles old because they and the injector pump and PCM were changed the last time. This is the second time for the same problem. I don't have any confidence in the dealer or other dealers that I have called. All of them seem to want to change parts, and than see if that cures the problem. I have checked with local diesel shops and none of them want to tackle it. They don' have the training or the electronics. Am I being stuck for unnecessary repairs? Is this the only way to diagnose? Anyone know of a good shop in Northern California. How about recommendations of a good shop anywhere? At 168,000 miles this is all out-of-pocket. Thanks.

[56Nomad]

Tony,

I recently read that California's new law requires
that manufacturers warrenty their injectors
to 300,000 miles. I'll try to check on that

[56Nomad]

Tony,

I posted an article on this info months ago, but can't find
it using the search. Nothing pops up on
Google either. Sorry :(

I'll keep looking

[OC_DMAX]

56Nomad,

Are you referring to a new law (?) or to the recent court settlement with GM for defective injectors in their gas engines?

The recent settlement in California with GM was only for injectors in gas engines (not for ones found in our DMAX's). There has been a 5 or 6 year history of failed injectors in some GM gas engines when using certain brands of gasoline. The settlement was for $400M (to pay for out of warranty repair costs) plus an extension of the warranty period for the injectors.

Would be nice though to have a 300K mile warranty on our DMAX injectors!! Can only hope.

[56Nomad]

Thanks for the correction.......

[truck_n]

Thanks for the effort and thoughts on the extended injector warranty. It would be nice. I guess I'll just have to watch my wallet!

[dmaxalliTech]

buy the way your readings are, it did need a new regulator, and your post readings verified that.. Injector data all seems ok, I would have to wonder if maybe its not burning oi alittle, are you loosing any? Does it smoke only at idle, warm, cold? They wanna just through 4 grand worth of injectors at it?? LOL :eek: :eek:

[truck_n]

dmaxalli,
It burns no oil, it gets great mileage, it smokes only at idle, very little smoke cold. Other than that, the truck runs great. They think 4 injectors are bad but they suggest changing all 8. I am waiting for the tech to call to tell me which 4 injectors he thinks are bad. They are planning to do a leak test by removing all of the glow plugs, then turning the engine over to see if there is any raw fuel pumping out of the cylinders. I should no more today.

[Kent Tuttle]

I bet if this was a warranty job they only would be replacing the 4 bad injectors and not all 8. Funny how that works with some (not all) dealers :rolleyes:

[Kennedy]

It would be interesting to see just what they do when tested. Dunno if you can afford the down time but:


If you plan to throw parts at it, I'd be inclined to try to pull #1 as it apppears to be a real hoser...

[dmaxalliTech]

TonyV, could you email me, I want to call you regarding this problem, maybe I can help..

[Kennedy]

Y'know, on the one hand it would be neat to replace the ones that can be shown bad, but on the other hand, knowing the miles on the current injectors, it may just be best to start fresh and have 8 matched injectors rather than risking having the others fail sooon after.

Were the current injectors pulled from a 2001 truck? Seems they are much more prevalent to fail...

[truck_n]

dmaxalliTech,
I sent an e-mail to tqauto@aol.com with my phone numbers. Thanks for your consideration.

kennedy,
The replaced injectors were out of an '01, and I here what your saying about replacing them all. That is the dealers logic as well. I just can't believe all of the injectors are bad, when they only have approx 60,000 miles on the replacements.
Can individual injectors be checked? If I replace them all along with the fuel pressure regulator module which has already been replaced, were talking almost $6000.00! Fortunately, right now, I can afford the downtime.

[mtomac]

If you decide to replace all 8 injectors see if you can get the old ones if there isn't a pricey core charge on them.

[truck_n]

M Tomac,
I should be able to keep the injectors because they are new. Do you know of anyone that rebuilds them?

[Kennedy]

There aren't nozzles avail for reman, but they can be checked and some parts changed.

Core charge is $100 even on NEW injectors.

I've had a number of injectors tested and have determined that they fade fast. I had a set done up for my truck, but am now waiting for some new nozzles or injectors so that I can have them balanced to a much finer point. The ones I had done weren't necessarily bad, just not what I wanted...

[dmaxalliTech]

tony, sorry, I didnt get your email. could you try again please. Click the email link in my sig and try that. Thanks.

[Kennedy]

One thing I see also is that the general pulse length is kinda short. Typically lower .40's are the average.

[truck_n]

dmaxalliTech,
I sent another e-mail to tqauto@aol.com today at about 9:15 am Ca. time. E-mail me at truck_n@msn.com if you do not get it. Thanks

Kennedy,
In response to your comments: What does "fade fast" mean? What is your criteria for "bad".

By the way, Injector #1 has 168,000 miles on it, Injectors 2-8, have approx 60,000 miles. I am still waiting for the dealer to do the fuel leakage test.

[Kennedy]

Tony,


While these injectors are electronically controlled, they still have the same mechanics dow low. They still have to hold to a certain "pop" pressure etc.

Most of the used injectors I have had tested have been low on delivery by 20% or more. This seems to follow the nozzle assembly when swapped from injector to injector. Simply put, the fuel charge is sent down to the nozzle, and part goes out the holes, and part goes past the nozzle pin clearance to lube/cool the injector.

Good possibility that injector 1 is sticking or not sealing/popping low. Keep in mind that balance rates are only an initial observation...


Some have problems seating and leak

[truck_n]

Kennedy,
You and dmaxallitechs feedback on this problem has been invaluable to me. I thank you both profusely for sharing your expertise.
My gut feeling is that one or more of the injectors leak. Can we tell accurately by the fuel leak test the dealer is planning to do if they are? Pardon my lack of knowledge, but are injectors and nozzles separate items? Are nozzles integral with the injectors?
You said "injectors you have tested". The dealer said they can't check individual injectors or for that matter any individual part. Do you offer this service? or is this something you have done for yourself? Thanks again, and please let me know if there is anything I can do for you.