Any diesel techs out there? HELP?

[autolodge]

I am a small shop owner that mostly does brakes and tires....and I am stumped. That being said, I need some help with a 99 ford F350 7.3 auto that is lacking power and running rough. It has three DTCs, P1271, P1273, P1275 which is an open circuit in the #1#3#5 injectors, wiring harness or a Failed IDM.

I have read that I need to test injector resistance at the valve cover plug, but need a very "kindergarden" explanation on how to do it. Also, what resistance should the injectors have at the valve cover plug and if they ohm out fine, where is the IDM located? and what does IDM stand for? I read it monitors the injectors. You will have to excuse my lack of diesel knowledge, I have no diesel ed and my manuals are junk. When it comes to diesels, they read "bring it to ford"

Thanks, Craig

 

[iroc1132]

stroker

There is a good chance the valve cover gasket/wire harness is unplugged or shorted to open inside under the valve cover. It looks like it is one bank that is giving you trouble. I'd bet the glow plugs aren't working either. All the wires are embossed in the gasket and over time the heat, vibration and oil get to them and they break or just come unplugged. Ford has some wedges that lock the ealier model plugs so they don't come out. The new gaskets should come with the updated plugs and wedges. You may be able to just plug them back in and lock them and not have to spend big dollars on a set of valve cover gaskets. Are you feeling lucky? This would be the first place I would look, it is not uncommon.

 

[aueland]

The IDM is located on the driver side fender wall inside the hood pretty close to the back. They do go out every now and again.The IDM is basically an amplifier. I'm leaning more toward the valve cover gasket like iroc said.
Alex

 

[ACTM7]

7.3

i would say its a safe bet valve cover gasket which has wire harness for injecters an glow plugs in it has a problem. them years did have a change in the gasket because . they would burn the wire connecters under valve cover. dont now spec off top of head but if you measure restance of wire connecters on other side and compair you could tell if problem is under valve cover [most of the time it is ]or in harness to valve cover.

 

[omernikski]

Check the engine harness where it plugs into the valve cover gasket, I have found burnt pins on alot of trucks and rebuilt alot of harnesses with similar problems

 

[omernikski]

A failed IDM will usually cut the whole side not just 3 injectors.

 

[autolodge]

good stuff

Thanks guys, looks like I will be pulling the passenger side valve cover. the plug in was OK with no visible discoloration, burn or corrosion on the plug electrodes. Thanks for the responses, I will post what I find. Craig

 

[Blk88GT]

http://www.thedieselstop.com is the snowest of Ford diesels. If you can't figure it out, someone there surely can help you.

 

[Powerstroked162]

http://www.Powerstrokenation.com is the snowest of Ford diesels. If you can't figure it out, someone there surely can help you.

Fixed it for ya

Cowboy Steve

 

[autolodge]

fixed IT!!!

Thanks for the imput! Turns out the pins where the Injector harness plugs into the valve cover gasket were burnt. Replaced the gasket and injector/glow plug harness. She runs like a top. Thanks again, Craig.

 

[Blk88GT]

Powerstrokenation might get more traffic, but you can only read so many posts about headlight and grill swaps before it makes you crazy.

 

[Powerstroked162]

Powerstrokenation might get more traffic, but you can only read so many posts about headlight and grill swaps before it makes you crazy.

Haha, thedieselslop.com might have more tech info and write-ups but its all from '03. Everybody who wrote those threads, or posts are playin on the nation now, mostly because Autoforums.com now owns thedieselslop.com and thus completely ruined it entirely.

Cowboy Steve

 

[autolodge]

F#$K ME! you fix one diesel........

New problem. I fixed that ford, and the guy was so impressed that someone was willing to look at his deisel way out here, that he ran down to the coffee shop and now I have done four in three days, including an EGR cleaning on a 6.0L. Just looking for common causes for a 95 Chev K3500 with the 6.5L turbo diesel (boat anchor) motor to loose fuel pressure to the injectors. Guy was driving down the highway and it started running ****ty and quit. It is now a no start. I have fuel pumping up to the filter (replace with new) but when I crack the nut on the Injector I have no fuel. Is there anything other than the injection pump itself that I can check? It will pop on either but Still no injector pulse. Am I on the right track?

 

[Joe Mama]

Craig,

The 6.5's have two major problems. Check the lift pump on the frame under the drivers door. This little can with two wires runs about $90 and is the cause for most fuel problems on the 6.5's. Its a bugger to replace without getting soaked, I use the plastic cap that comes on small tubes of blue RTV simply pull pump and slip the cap into the fuel line going to the tank.

The other problem is the PMD (pump mounted driver) it controls the main injector pump and is prone to failure from heat. Check with Heath Diesel for their PMD relocate kit to solve all of your problems. Heath Diesel is about the only game in town for the old 6.5 performance parts. When the PMD fails the truck will typicaly die then fire right up again almost like it was an electrical issue.

 

[autolodge]

yup

Sounds like the PDM. He was having problems with a phantom die and restart problem that eventually turned into this dead on the side of the road. It has fuel up to the filter housing on the back of the motor so it isn't the lift pump. Time to start reading up on the pdm. thanks again, craig.

 

[omernikski]

Joe Mamas right, those 6.5 are notorious for driver problems

 

[MCIVER]

I rebuild those pumps all the time and this problem your having is more than likely the pmd on the side of the pump or the encoder sensor in the pump.

unplug the sensor that comes out of the top of the pump (square plug), then try and fire up the truck. if you can get it to start with the harness unplugged you need to get a new pump.

pm me if you have questions or want a pump or parts.

 

[autolodge]

???

If I unplug the sensor and the truck starts doesn't that mean the pump is good and the sensor bad? Or am I backwards. I have been reading on the pump mounted driver (PMD?) and it looks like there is no way to test it except replace it. Any way to see if the pump is good in the truck? If not, I am just going to shake the dice and replace the PMD. Thanks, Craig

 

[MCIVER]

autolodge;1514600]If I unplug the sensor and the truck starts doesn't that mean the pump is good and the sensor bad? Or am I backwards.

you are right, but the problem is you shouldn't just swap out the sensor cause it controls you fuel amounts and needs to be calibrated on the test bench for 29.5mm3 to 30.5mm3 of fuel flow. not to mention there is a very thin data track disk that the sensor slides over and it is very easy to crack or break that disk.

there are ways of testing pmds but requires specail test equipment from stanadyne.