Saw this post not too long ago with a place that tests IDM for $30.

https://www.ford-trucks.com/forums/1...l#post15277843

Maybe this is an option?

 

Thanks fo the reply, I suspect the IDM shut down the right bank because the high resistance in the UVCH and it won't reset even though I replaced the UVCH on the right side and cleared the codes, an injector buzz test has weak buzzes on all 4 cylinders on the right bank and strong buzzes on the 4 cylinders on the left bank, and code p1293 is still present and #3 cyl contribution is still failed. There is no wiring damage any where that I can find so IDM is suspect, and my neighbor knows where there is a wrecked truck like mine being parted so I intend to buy that IDM and also send my other dead IDM from last years UVCH failures in for rebuilding.

 

Both under valve cover harnesses have been replaced, I now have a replacement injector driver module, but I don't dare plug it in because since the main problem I am having is code 1293 right bank high side open and when I check the ohms through the 42 pin connector I get high readings 17.8 ohms 21 ohms and so on but I also get the high readings on the drivers bank that runs. Using the break out tool I had readings at the valve cover connectors at 10.9 ohms one day then 5.3 ohms another day and back up around 17 ohms yesterday on the right bank and 8.9 highest reading on the left (running) bank. This suggests that the entire right bank of injectors are shot which makes no sense on an engine that has had proper oil changes and maintenance and was running perfect all last year and right up to when it stalled out. No visible damage to the above valve cover wiring harness on top of the engine. I have no clue where to go from here.

 

Ouch. Let's take a check of one of your suspicions, that the ohm reading aren't consistent.

Tell us about the meter you are using (brand/model) and does it have a new battery? Ohm readings use your (possibly marginal?) internal battery.

It's a start

 

Ah... this is actually a good thing - you have something solid to troubleshoot (instead of a mystery gremlin with no detected "signature").

The problem is clearly somewhere between the 42-pin connector and the solenoids, which includes:

• 42-pin itself (never saw one fail yet)
• 9-pin connectors outside the valve cover - male and female.
• 9-pin connectors inside the valve cover - male and female.
• 2-pin connectors to each injector - male and female.

With the whole bank causing issues, I strongly suspect the center pins on either of the 9-pin connectors. The highest suspect on my list is a bad inside center pin on the valve cover gasket. When you did your UVCH work, did you remove the valve cover gasket, then clean and closely inspect all the pins? This is what I found to cause a fail on an Excursion one time:

 

Thanks for the replies, my ohm meter is a new cheap one from harbor freight. Rich, I did not take a good look at the 9 pin connectors on the main engine harness, the valve cover gaskets were replaced with new ones with the injector and glow plugs harnesses integrated into the gasket. I will definitely check those out, and my break out tool is home made from an extra pig tail that was supplied with the UVCH so I have more of them and may need to make a new one for testing an perhaps invest in a better quality ohm meter. Thanks again, guys for the replies all advice is greatly appreciated. Jim

 

The HF DVMs are fine for continuity and for rough voltage (not tenths), but shouldn't be relied upon for fine voltages and not definitively for resistance- Ohms.

It does seem like a wide swing, so probably you are finding the problem. But a quality DVM would be an excellent tool to have in your kit

 

I purchased a better quality multimeter today, did not have time to do any testing, been working nights severely limiting my available daylight hours for working on the truck. The new meter also has continuity testing ability and very long leads so I will check for continuity between the 42 pin connector and the 9 pin connector on the main engine harness, and of course take all new ohm readings at the 42 pin connector, both 9 pin connectors at the valve covers, and if need be at the idm connector.

 

Good move. If you are going to use the results of your tests to determine if/when to spend money, it's wise to have a reliable testing instrument

Good luck on your testing. Lots of good folks here know their stuff and can help guide you through the various tests

 

Today I had the chance to test the wiring with my new multimeter, I had continuity from the 42 pin connector through the main engine harness to the right side 9 pin connector. I hooked up my break out tool which I discovered had a loose blue wire which could have messed up some of the earlier tests, and checked all ohm readings on both sides and all 8 injectors are at 2.9 to 3.1 ohms. The next tests I ran were per the gb tech bulletin 103 at the idm connector and all the injectors and wires there at the connector had the proper 2.9 to 3.1 ohms, and the other tests show no shorted wiring. I hooked up my snap-on mt2500 scanner, cleared all codes before plugging in the recently purchased idm. It passed all koeo tests with no new codes and then passed the injector buzz test. It cranked up and ran perfect after that so I put everything back together and went for a successful test drive. I am pleased that its up and running and very grateful for all the advice from everyone. None of the money spent on the diagnostic tools or replacement parts was wasted since the cmp, and idm and both side uvch were all needed to fix it. It is however annoying that last years repairs I did only lasted 14 months, and now we know that an idm can just drop one bank forever. So now I have 2 dead idms I can send in for rebuilding. Thanks again to everyone who replied and advised me on this thread.

 

Shweeet!!!


Isn't is amazing how you get a sense of how everything works together? It's a good feeling once you get the major stuff in spec and start seeing everything else fall into line as you finely focus each one

Now you can start running some OBD loggers (torquepro or autoenginuity or infinity) and start graphing under certain conditions to get an even more detailed look into the health and performance of your rig

You should start "feeling" the differences as you drive

Great work!!!

 

Ah... good test equipment was the key in this instance. Congratulations on the fix! Thanks for reporting back, it's helpful to all that follow you.

 

Anything to update us on , sounds about the same issue I'm having...

 

I don't have any updates because after the last fix described in this thread, I have not had any more trouble with my truck. To recap, the main problem was an aftermarket cam position sensor that caused the engine to buck from time to time and it caused the engine to shut down so hard that it unplugged the under valve cover harnesses leading to the injectors, and that shorted out one half of the injector driver module which made the truck only run on 4 cylinders. I replaced the C.M.P. first which got it running on 4 cylinders. The tests described in this thread, discovered the bad U.V.C.H. and bad I.D.M. I replaced both sides of U.V.C.H. with the updated type that can't come unplugged and replaced the bad I.D.M. all three repairs were needed to fix the truck. The breakout tool I described for testing is simply an extra valve cover harness plug that plugs in where the main engine harness plugs into the valve cover gaskets. I added wire connectors to each wire to make it easier to plug in the ohm meter leads to the individual wires. Read through the thread again and there is advice on how to test the wiring harness and I.D.M. There is a re builder on eBay that will rebuild your I.D.M. for $100.00 plus shipping. Jim