My saga of tracing out IDM codes

[TARM]

I have had something plaguing my engine for some time.

Engine seems to be running a bit rough. It has a rough somewhat lope idle. When dropping down to a stop the idle is even rougher but smooths up one stopped. Its those little things you notice when you know your truck. Something is just not right.

I am getting a hard CEL every time it starts and it does NOT go out.

IDM codes:

P1316 (Generic IDM code)

The P1271-P1278 type codes. (Specific cyl below)


Cyl 1,2,5,8 High to low side open (as these codes indicate the issue is showing in both banks. This starts to lower indications its a wiring harness.)

Any IDM failures I had seen were always total failures. A entire bank or the whole unit. The least I saw as a complete loss of one cyl injector. But never any thing partial so I discounted it being the actual IDM.



Here is the diagnostics done:

* Ohm'd out the complete harness from IDM connector to injector so it covers the full travel.

- All circuits registered 3.0 ohm (In spec and normal according to IH and Ford being 2.8-3.6.)

* Buzz Test All sounded very loud and consistent. (These are new injectors that Nate had to replace a defective nozzle on. He went thru them in great detail and checked all specs. 200% hybrids)

* Just to be completely safe the UVC harnesses were replaced and the full harness was rechecked @ 3.0 ohms.

Nate had just gone thru these injectors as he had to fix a defective nozzle. Awesome guy BTW with great customer service. I had told him about the codes prior to him getting them in the mail so he meticulously went thru them to ensure it was nothing with the injector that was wrong or out of spec.

Well anyways I went thru a ton to testing and replacing parts to fix the rough idle and the codes.

Finally I dug up a IDM my good friend Addison had sent me for free so I could save some money by turning it in as an extra core to Swamps as I wanted one of those cool HV HF IDMs. If I had done that the issue would have been resolved as well. Figures it was the only upgrade I did not make and one of two I really needed LOL

I plugged in the IDM and ran the Buzz Test for what must be the 100th time

The read out came back:

TEST COMPLETED SUCCESSFULLY!!!!


Moral of the story. Do not be a Dumbass as I was and ignore the obvious and what the testing is telling you whats wrong.

If you get these types of IDM codes:

Check the connections at the outside of the VC.

Check the wiring harness where it touches the VCs for burnt or exposed wire.

Then pull the IDM connector as this will allow you to check the entire harness as well as the solenoid. If they all ohm the same or within 0.1 of each other and are all within the 2.8-3.6 spec then............

Swap out the IDM as the next step.

This is way faster and easier than pulling VC and swapping injectors or solenoids etc in an attempt to trace the issue unless its the ohm out procedure indicates this to be the issue. As I see it all you do is risk causing new issues by not getting everything connected back fully etc...

I was able to do all of this and swap out the IDM after testing in a total of 1 hr not rushing at all.



Basically I used these issues as an excuse to replace just about everything related to the injectors and hpop system LOL Not to mention a few other things since well everything was torn apart anways. That was the excuse I gave the Mrs anyways LOL

* Borg Warner CPS CSS1603 ( this is a duplicate of the old Black original CPS. Its grey but its full sized and has the same hall sensor specs, centered and right at the surface tip (you can see it thru the plastic) Test your intermittent wipers. If it causes engine surge or cuts out the Wiper motor is going bad and throwing interference thru the ground wire. It shared a common ground with the CPS and PCM (Can you say stupid) Cut the wiper ground where it joins and ground it by itself somewhere else. This will solve the issue. Advanced Auto with online coupon TRT30 and choose in store pickup $18. Huge dif in idle compared to Ford Grey)
* Ford IPR
* Ford ICP
* Ford Glow Plug Set
* Ford Glow Plug Module
* Ford Under Valve cover Wiring Harness Set
* Stealth SPR 1.1 HPOP
* Melling LPOP
* HyperMax Intercooler
* 6.0 Trans Cooler
* Inline Trans filter
* IH Coolant Pump (has intergated bypass filter)



Hoping someone may learn something from my mistakes.

 

[CSIPSD]

I am a huge fan of the Swamps IDM. I would put it up there with top 5 mods I have done.

 

[psduser1]

I appreciate your efforts, the devil is in the details for sure!

 

[TARM]

Sure is in the details no doubt.

The Swamps IDM is my next purchase



Another thing :

When I swapped out the CPS it knocked off one of the 4 cylinders failing the Contribution Test.

When I swapped out the IDM it took out the remaining 3 cylinders failing the Contribution Test.

Weird thing with the buzz test though. After I reinstalled the good idm (after getting the passing buzz test) upon start up got a CEL agian ( thought I was gonna put a wrench thru the windshield). Went in and it listed generic IDM code but no specific ones listed. Ran the Buzz test and I got 3 cyl fail. But then the CEL went away. Cleared all the codes and ran the Buzz again and it passed free and clear. Maybe something still stuck in the PCM memory? Anyways it did pass clear once I cleared the codes as well as the first time I ran it. We will see if that damn Cel stays gone now. Man I loath that light; Grrrrr...

But happy to see the contribution test run clear as well. Confirmations of sorts that the engine should be running better balanced. Now just some tweaks with tunes and hopefully all will be well and I can start enjoying driving it.

 

[JLDickmon]

on my shopping list as well

 

['94IDITurbo7.3]

so was the CPS the problem or the wiper motor ground?

 

[TARM]

It was a wiper ground on the ones I have seen. Mine had neither issue. But others have. Its not that surprising given the age of these vehicles. My issue was a crappy grey ford CPS. THe BWD was night and day different in the smoothness and sound at idle and take off.

Unfortunately I created a issue doing some testing and did not take it on the trip but the IDM fixed the high low codes and even before it the CPS swap took away a couple of the contribution test failures. They all disappeared with the IDM swap where before even when the IDM was still good I always had 3 failures using the grey ford CPS. Now with the BWD CPS I have none.

My point is if you try the BWD CPS and have issues like engine surge or cutting out when your wipers are on I would first try isolating the wiper motor ground rather than go to a different and crappier CPS like the current ford IH ones. If the only issue with a CPS is that its sensitive to electrical interference trash the wiper motor is spewing out which it should not b4eing doing why not fix the issue rather than switch to a worse performing CPS just because it is more tolerant of poor grounding.

When I get back from my trip I am currently on in a couple weeks I will try to take some step by step pics of the wiper ground and where to cut and splice and relocate the ground point. Frankly it seems like a good thing to likely do regardless given a electric motor can have these issues and if they are bad with the way its wired from the factory you can end up with a dead engine. Ford even did a notice on it I recall reading.