This cant be just our shop seeing this

Tony302600 · January 19, 2008

Keith me too, I had one injector letting combustion gases in, but showed misfire on 1,3,5,7 truck barely running.

LARRY BRUDZYNSKI · January 19, 2008

Showed this thread to my fuel guy today, he confirmed that the combustion gas getting by contaminated the rest of the injectors and make sure the rail was clean before reassembling. Mity vac is a cool thought but won't show whats down the line in the system. He did tell me he has had some luck flushing the injectors on his test stand but it's only 50/50 that it will work. Crap shoot at best... I say replace them the first time and be done.

Bruce Amacker · January 19, 2008

Originally Posted By: Bruce Amacker

Charles Ledger shot this picture of a vacuum test that is described in a TSB letter.

What TSB? Ford? I don't recall seeing this but it is basically the same as putting air at the nozzle... thanx for sharing this! The ONLY problem with this is I have had bad luck over the years with my vacuum pumps leaking. Mighty-Vac's they were, I now have a Snap-On which seems to be okay.

I e-mailed Charles and asked him. I had it wrong- I thought it was a TSB and it wasn't. His response was that Ford came out with a test adapter for the 7.3 to vacuum/air check them. He just modified that idea, since they had no adapter for the 6.0, using a MityVac. He says it works quite well, as the bad injectors would not hold vacuum.

I think I'll stroll down to the beach now. /forums/images/%%GRAEMLIN_URL%%/laugh.gif

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Tony302600 · January 19, 2008

I think I'll stroll down to the beach now. /forums/images/%%GRAEMLIN_URL%%/laugh.gif

/forums/images/%%GRAEMLIN_URL%%/grin.gif

I hope you get sunburned /forums/images/%%GRAEMLIN_URL%%/mad.gif /forums/images/%%GRAEMLIN_URL%%/rofl.gif

eastendpowerstroke · January 20, 2008

Well I never thought of using vacuum on the tip like that,I guess I had the idea that combustion/cyl pressure was bypassing the tip and airating the fuel so pressure was my choice but no reason that wouldn't work also. /forums/images/%%GRAEMLIN_URL%%/shrug.gif

Bruce Amacker · January 21, 2008

Well I never thought of using vacuum on the tip like that guess I had the idea that combustion/cyl pressure was bypassing the tip and aerating the fuel so pressure was my choice but no reason that wouldn't work also. /forums/images/%%GRAEMLIN_URL%%/shrug.gif

Shop air would be better. Remember that a perfect vacuum is only negative 14.7PSI- much less than shop air. Maybe do them both if you're not sure, to check leakage in both directions.

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Shlep · January 22, 2008

We had one of these not all that long ago, it was repaired at another dealer, sold at auction and UCS bought it. Another tech got it and it came in barely running, he did the balloon test thing and it worked pretty good and it confirmed what we had thought, but here's the strange part, the hotline engineer said to replace the hold downs and bolts. Informed that there was an issue with them being overtorqued at the factory, stretching the bolts and deforming the hold down. Just something you may want to watch for /forums/images/%%GRAEMLIN_URL%%/wink.gif

DamageINC · January 22, 2008

Well ok, to bring this one back up again...

..I have an '07 F-450 wrecker (badass mo'fo!) that came in BARELY running.

Sure enough, cylinders 1, 5, and 7 were dead. About 30 seconds into the power balance test, cyilnder 3 crapped out too.

After removing the ridiculous accessory mounted PTO pump and lines from the right side of the engine bay, I got the injectors out and surprisingly, every injector's copper "gasket" looks perfect. No real signs of any combustion gas making it past them. There's a *slight* brownish hue near the bottom of 2 of the injectors (5 and 7) just above the copper ring, but nothing even remotely combustion-gas looking.

There IS, however, what appears to be -rust- all over the fuel inlet port area of all 4 injectors. I'm very skeptical to flat-out call it rust, because if it is then it's definitely not Ford's responsibility and we'll have to have a talk with the customer about fuel quality and filter maintnance.

Oddly enough, the RO says "Customer can't go over 30mph, runs rough, cust changed fuel filters and fuel and problem still there" Now who actually changes fuel filters AND fuel unless they themselves think that maybe the shit in their tank, isn't supposed to be in their tank.

The injectors defiitely seemed properly secured, and like I said, I don't really think I see any sign of combustion gas getting blown past the seal. At least nothing even remotely charred, black, or anything like that... just a slight brown, pyramid-shaped "stain" covering about 20% of the lowermost portion of 2 injectors, directly above the copper seal.

Any thoughts?? I think I'm dealing more with a water-in-fuel issue than anything...

Dave

Jeff_E · January 22, 2008

Hey Dave,

I dunno, If it were a water in fuel issue wouldn't it affect

BOTH banks? As I contemplate all of the things that cylinders 1,3,5,7 have in common regarding the fuel system... the banjo fitting in the front of the RT cylinder head comes to mind. There should be a check valve in there that prevents fuel pressure spikes from going back through the line to the filter housing. If that banjo fitting check valve were restricted or not working properly it would affect all 4 of those cyls. As you know these injectors are VERY sensitive and can easily fail from low fuel pressure. 45 PSI is a bare bones minimum. A restriction from that check valve would show normal fuel pressure when tested at the filter housing which is upstream, but in actuality you could have low pressure to that bank and not even know it. Just a thought

Bruce Amacker · January 22, 2008

Sure enough, cylinders 1, 5, and 7 were dead. About 30 seconds into the power balance test, cylinder 3 crapped out too.

I think I'm dealing more with a water-in-fuel issue than anything...

Dave

If I had seen this, I would have explored a dead bank a bit more before teardown. I'd have pulled the FF or FF line, disabled the FP and looked for air coming back (or balloon test) cranking. I'd also have used the homemade light bulb to verify injector power. I agree with Jeff, if you have 4 dead on one side, it's probably not fuel quality as your prime concern. It definitely is your secondary concern, though. Will Ford pay to hang 4 injectors and ship it? The fuel check valve may or may not be a source of trouble, as I can blow through them both ways with my mouth. Checking it is a good idea, for sure.

Good Luck!

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DamageINC · January 22, 2008

Well, this is kinda a "hand-me-down" job in which I just happened to be there when our other tech was doing the initial diag on this vehicle. After he popped the hood and saw the aftermarket PTO pump and bracket, he basically decided he was too busy for this one and asked me if I'd do the 4 injectors for him. So I did...

..it wasn't until after I pulled the injectors out that I noticed the rust on the inlet ports and began questioning the initial diagnosis. Looking back, we definitely should have done the bubble-check. Had I been the first guy to look at it, I probably would have checked for bubbles in the FF housing. I'm not throwing out other guy under the bus or anything, he's a great tech, but I think the gun was jumped here maybe.

Dave

Rickster42 · January 22, 2008

The last 3 or 4 times I had problems with comb gases on a bank,I never saw any obvious signs on the injectors. I would power balance to see which bank was the problem. Quite a few times on a cold start, there will be one inj misfiring, then quickly followed by the rest of that bank.The one misfiring first if you can catch it is the root problem. I then usually take the comp tester adapter and apply shop air to each cyl on that bank and look for bubbles in ff or air in balloon. That works real good. But it`s only effective if the vehicle hasn`t run very long or the other 3 on that bank are already dead(they just don`t know it yet...)

Tony302600 · January 23, 2008

Dave, if you have a fuel quality issue it would affect both banks, With fuel quality i've found random misfires. Also when i have codes for right bank injectors usually more than one, 100% of the time when i get it running my fuel pressure gauge will fluctuate from 45-25 rapidly indicated combustion gases in the system.

Bruce, Ford does not pay just to through 4injectors in and ship it. They want to know WHY they failed or what was the root cause. I've had injectors just fail, with awesome fuel pressure after the repair. Documented it and never heard anything from the nazi's.

I do know that low fuel pressure will show at the right bank first. Thats from Ford and the international engineer i know.

And dont forget you CANNOT go off of fuel color due to the face that Ford said so. Appropriate cetane could be berry blue in color if the supplier wanted it to be.

BTW i have fixed a lot of drivebility issues with just fuel filters nothing else.....especially lack of power on e-series