VT-365 Cylinder Contribution

[Keith Browning]

Apparently all problems cross the boundaries from light duty trucks to medium duty. Funny thing is that Recall 07S57 has brough more medium duty 6.0L trucks to me in the last month than I have ever seen! Sitting in my bay right now is a 2004 F650 with a VT-365 that lacks power under a load. It had a light miss and idles rough. No DTC's. Long story short, the fuel tanks are rusted internally. You know the story but these tanks are not laminated. The truck is a rust bucket used as a salt spreader in the winter.

 

So, I am reaching out to the International guys or those who are familiar with Master Diagnostics. We know that the software is nothing like the IDS is. No active commands and limited diagnostics. But, we can use injector disable and monitor the average fuel rate to identify the slackers.

 

My cutoff deviation value was 0.10-GH over the base line of 0.48-GH making it 0.58-GH. Cylinder #8 shows only 0.53 which is well under the cutoff. My question to you guys; is ANY reading below the cut off unacceptable or is there any "golden rule" for flagging an injector... provided fuel, oil pressures and mechanical issues have been ruled out?

[Bruce Amacker]

I wish I could be of more help here, but I see a hundred DT's for every VT365 I see.

 

Here are a couple of captures I have on file for VT's, I think the first is a known good and the second is a known bad.

 

 

 

Have you done an injector waveform in CCT/IDT and expanded the screen out? The test drops cylinders and compares fuel rates and load in a graph, it's a little known but very important part of MD Fleet. This is what a known good DTEGR looks like, what you want to see is each cylinder being the same. The six sets of humps correspond to each cylinder in a DT. If you have one graph lower than the rest, it shows a bad cylinder.

 

 

 

 

FWIW, IH had a bunch of NGV's in 2002 that were built with rusty fuel tanks from the supplier. Filters will not catch rust in any engine and it will trash the barrels and plungers in the injectors. They had repeat injector failures in these trucks and ended up putting new tanks in them to solve the problem. I bet the supplier was backcharged for this, rumor was they left a bunch of new tanks outside and they got rain inside of them.

Good Luck!

 

 

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[SteveS]

Sorry to go slightly OT

Filters will not catch rust in any engine...

Is that rust that is smaller than the micron rating of the filter? I have found flakes of rust in filter canisters, does that mean that surely there has been smaller rust particles pass through into the injectors? Always?

[Bruce Amacker]

Sorry to go slightly OT

Originally Posted By: Bruce Amacker

Filters will not catch rust in any engine...

Is that rust that is smaller than the micron rating of the filter? I have found flakes of rust in filter canisters, does that mean that surely there has been smaller rust particles pass through into the injectors? Always?

 

 

Rust comes in many sizes, and rust contamination is never limited to one size. That means when you have rust, you have all sizes. If it's larger than 10 micron, the primary filter catches it. If it is between 4 and 10 micron, the secondary filter "should" catch it. The trouble is that the rust powder that is finer than 4 micron gets through both filters, and acts like liquid sandpaper on the injector barrels and plungers. The result is considerably shorter injector life. It is a death sentence to see a filter with a lot of rust in it and you should sit the cust down and explain his problem to him in clear detail. The tank needs to come out and be cleaned/coated/sandblasted/replaced. If he ignores this situation, it is common to be right back at square one with bad injectors in a short period of time. I've seen this numerous times, and IH had a clear problem with it several years ago like I stated. If the cust declines the tank service, you should note this on the work order so if it comes back the SM can make his call then. This is part of the reason I'm so anal about taking a fuel sample from every vehicle I work on. I want to know what's in the filter!

 

Good Luck!

 

 

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[Keith Browning]

One picture is worth a thousand words. This is from the FUEL CONTAMINATION ARTICLE showing a rusted Super Duty tank. The fine rust Bruce mentioned will discolor the outer part of fuel injectors where the fuel rail supplies fuel to the injector. The same rust that is fuel borne enters the injector where it does the damage.

[blown99]

If both values are below the deviation then the injector is bad. I am not sure how the ford system works, but with MD, you calculate an average of the eight injectors, and take the worst (below the deviation value) as the bad. You can install the replacements and perform the disable test again, and fail several more. It used to be, if I saw an injector that was at, or just a hair better than the deviation value, I would change it. International changed their policy back in November. If you have one bad inj. replace it. Any more than one bad, then all eight get replaced. International still has problems with rust in the fuel tanks. I've had several 466 egr motors that were hard starting due to rust built up around the injector inlet screen.