Hi guys, I'm normally on the 99-03 PSD forum, but have been working on a 96 PSD at work. I've pulled 2 codes from the computer. Injector Circuit 4 and 8 Low. From what I can gather from my search of the forum, it would be the under valve cover harness. So far I've replaced that and the valve cover gasket (haven't tried to start it as of yet) I'm still waiting fot pigtail repair ends for the engine harness. When I pulled the front connector on the drivers side head, closest to the firewall, I noticed the glow plug pins were melted quite badly, so when I get my repair ends I'll try it. But as for now, is there anything else I should be looking at/for?

Thanks in advance

 

Tep you likely found your trouble. The harnesses are known to melt. I would replace everthing that look s suspect. Be sure to check the harness under the valve cover for rubbing. I would leave the valve covers off for the initial start up. Look for oil pizzing out of the small hole on each injector. It's a quick way of determining if all the injectors are firing. Good luck...let us know how it turns out.

 

yup, sound liek the typical problem, good find, if you wanted too you could clear the codes and run the injector electrical self test before you fired it up.

 

So.. I got to work on the truck for a while today. Put the harness plugs on, and tried firing it up. It worked a little better, but only marginally. It got rid of #4 cyl circuit low code. But still not good. I'm beginnig to lean towards the IDM, since I checked all the resistances in the injectors using an old harness plug, through the uvc harness, and from the IDM harness plug to the uvc plugs. Does it sound possible to have an IDM that won't fire on only one cylinder? Starting to drive me a little screwy, doesn't help I'm also trying to get broken exhaust manifold studs out of a C-12 cat engine while working on this truck too. Nerve wracking... Anyway.. Thanks guys

 

I would rule out any & all potential wiring problems first .

What were the numbers on the Injector with the meter ...?

 

Rick
I will add.
Possible loose poppet screw.

Bill

 

You're alway's one step ahead of me ,,,

But I have all the beans .....

I wasn't sure it would show up on a scan...

Thinking solonoid .....




Love the avi....

 

Ok.. so the numbers on the injectors seemed to be lowering as the engine was cooling down(tested them after running engine for a while) All 8 injectors measured the same. Should I have measured them cold? Is there a magic number? As for loose poppet screws I have no idea. Are they the torx head screws on the tops?? What are the torque specs? Sorry for all the questions but I'm grabbing for all the straws I can on my way. Thanks for all the help

 

Some help ...here.... & ...here...the second link is more informative

 

if you suspect the idm is at fault you can probe the suspect cylinder for voltage pulses while the engine is running.

 

If you decide to do that be aware there is 115V DC on those wires.

 

yeah, either lick your fingers and stand in a bucket of water, or use a voltmeter

 

Well, I was right to suspect the IDM. Customer brought me one in, and it took right off. Thanks to all of those who helped.

 

glad to see its up and running