My trucks an early 99. I'll check the center pin and whether the harness is laying on the valve cover or not tomorrow. Thanks guys. Will let you know what I find.

 

The pass side center pin measures 1.332v and the driver side 4.54v. Is this correct for the pass side or does this tell me I have an open circuit of some sort?

 

That is about what I measured on mine. I was not sure why they were different???????

 

I don't have a wiring diagram for the early 99. Voltage above 1 means the issue is intermittent if you're positive there are no issues under the valve cover. If you grab the wiring harness and wiggle it (careful there's high voltage in the injector wires) does the voltage change? Can you see the colors of all the wires or by process of elimination try ohming the wires between the flat 9 pin connector at the valve cover and the 42 pin connector over the drivers side valve cover? Then ohm with wire from the 42 pin connector back to the IDM. Make sure to wiggle the wires while checking ohms to see if the reading starts to jump or fluctuate.

 

Chris,

I'm not sure I'm following you on this statement: "Voltage above 1 means the issue is intermittent if you're positive there are no issues under the valve cover"

I measured almost the same on my truck that was running good. I agree to measure the wires from the idm to the 9 pin connection for continuity.

 

Voltage above 1 is normal. That would mean he either has an issue under the valve cover since those wires were not included in this test, or he has an intermittent problem that was not showing it's face during the voltage test. Maybe it takes a certain bump in the road, engine vibration, heat coming off the engine, etc. to trigger the issue and make the voltage reading change to less than 1 volt.

 

Both the harness and valve cover gasket have been replace on the pass side so I'm pretty sure I don't have an under the valve cover issue. I'll try the "wiggle" test and ohming out all the wires back to the IDM and see what comes up. Also, I'll do a closer inspection of all the wires from the IDM to the injectors to see if maybe it's rubbed through somewhere.

 

Also, since I have 2 IDM's (the original and the reman unit). Is there a way to tell if either or both are bad? Just want to rule that out as a posssiblity since you'll notice in my early post when I repaced the original with the reman unit, it started right up. But, I was only able to drive about a 1/2 mile when it crapped out.

 

The odds of both of them being bad and behaving in the same way are astronomical.
I think you have two good units there, and the problem lies elsewhere.
I haven't checked back through this thread, but have you tried swapping some relays around?

 

Nope. Haven't tried swaping relays around yet. Do you mean the relays in power distribution box under the hood on the drivers side? I checked the owners manual and it doesn't list one specifically for the IDM. Which one's should I swap around?

 

Found the IDM relay in the power distribution box and switched it with the blower motor relay. No luck, same problem. I found a wiring diagram on powerstrokenation.com forum and used it to toned out the four injector wires from the valve cover harness back to the 42 pin junction box and then from the juntion box to the IDM. I went ahead and checked both sides just in case. I performed the "wiggle" test on each one and all have continuity all the way back to the IDM with no change in ohm reading. I also didn't notice any wires that were rubbed through their coating or were freyed or burnt.

Using the scan tool, I performed the Continous Memory Test. Along with the same P1316 I'm also getting a P0603 - Power Train Control Module Keep Alive Memory KAM error. Does this indicated any other issue?

Where should I look next?

 

Guys, you're not going to believe this. Since I hadn't tried running the KOER test with my new scan tool, I wanted to give it a shot. So, I started the truck, and of course it's running very rough and the Service Engine Light is on. When I attempted to run the KOER test the scan tool kept telling me it had a communication error and couldn't continue. I began reading the scan tool manual thinking maybe I missed something when all of a sudden my truck starts idling smooth and the Service Engine Soon light goes off. Remind you, the truck is sitting still just idling. Go figure? With the truck idling smooth, I thought it was a great opportunity to do a complete "wiggle" test on all the wires to see if I could get it to run bad and the Engine light come on again. Well, I wiggled, and wiggled and wiggled all the injector wires from the UVC harness back to the IDM. Nothing! Truck is still idling great. I then proceed to go ahead and run the contious memory test again and I'm still getting the same P1316 and P0603 codes. I also ran the KOEO test and it's still getting the same P1293 - Injector High Side Open Bank1. How could it detect an open circuit if its now idling smooth and the Service Engine Light has gone off?

 

Did you clear the codes?

 

The PCM stores the code from when the light was on. If you've ohmed and checked things from the valve cover back to the IDM, then I'd say it's time to pull the valve cover and check the "new" stuff. Start with the pins in the pass thru connector. Try wiggling the pins while checking the readings to make sure it's not a broke pin in the gasket. Then start testing the wires in the new harness.

 

Just finished driving the truck for ~ 3 miles. Drove slow for a while and then got down on it a couple of times. No problems. Truck is running normal. I'm going to clear the codes and re-run the KOEO test again to ensure I don't have any codes. If it happens again, I guess I'll check the "new" gasket and harness.