Update...

I just got back from Jody a pcm he flashed his econo tune on. Truck has lost the relay buzzing and hard starting issue now that I have a fully functioning pcm. No code retrieved on AE right after installing the pcm however, the engine miss was still there like before.

Now that I've put on a few miles after installing the tuned pcm, the engine miss is getting progressively more pronounced. It's to the point where the truck is starting to shake quite a bit usually at the lower rpm range while at higher rpm's it does smooth out somewhat.

Today, after running the injector buzz test on AE I received the codes P1271, P1272, P1273, P1274, P1275, P1276, P1277, P1278, and P1668. The first 8 (P1271 though 1278) are for cylinder 1 through 8 High to Low Side Open and the last one (P1668) is PCM -IDM Diagnostic Communication Error. I have run the injector buzz test a few more times throughout the day and each time I get P1668 and the others haven't shown up again. Does anyone know if this is an obvious IDM problem, wiring problem, or other?

Thanks,
Drake

 

Drake,

I used to get the P1668 everytime I ran a buzz test with my old XLE4 PCM. I now have a PMT1 PCM and don't get that code after a buzz test. The truck always ran well on either PCM. I'm still running my stock 110 volt IDM.

 

Might sound silly, BUT I just got rid of my miss myself! Took me a year or so to figure out! My problem was a combo of grey cps and synthetic oil. I only run motorcraft in my truck from now on! My miss was mostly about 1700 was the worst with foot barely on the Peddle. When I had a load or mashed on it the miss vanished. I say my injectors are probably getting tired or at least the o- rings. Hopefully a fresh oil change with Dino will be your solution!

 

I have the black CPS from Clay at RiffRaff which is supposed to be original black. I'm currently running Rotella dino. Cylinder #3 and #8 do have higher rotational velocity numbers. Especially 8 which is about 3.8. I know this potentially points to the CPS, but I thought the symptoms of the black one was it just quit working suddenly.

What are the symptoms of IDM failure or issues?

 

I also wanted to add something I forgot about. When I checked AE today and one of the DTC codes was for either low battery or low voltage. I can't remember exactly how it read. Could low voltage or an alternator load cause the IDM (faulty or otherwise) or anything else to produce an engine miss?

 

I forgot to mention when I changed my cps out I unplugged both pin plugs to valve covers and inspected and then I plugged In and out two or three times I guess just to make myself happy but this may have been part of my problem as could be yours? Might not be getting good connection. Just food for thought.

 

Thanks Blaine. I'll give this a try today. I also have another new black CPS laying around and I'll try putting that one in to see if it makes a difference.

-Drake

 

Not sure if this will help yea. But here is some information.

First pic. Truck had the new revised CPS from ford installed from recall. lol
Second pic.. Got black International CPS from Clay.. Numbers looked better.
While trouble shooting a #8 knock i found that #2 had a ripped oring. (got lucky finding that). I suspect it was pumping air into the oil, Just a guess. but knock gone now.. And Now the number 2 injector is suspect due to high reading transfering from #8 to #2. Link to thread https://www.ford-trucks.com/forums/9...oring-pic.html

Not sure if this relates to your problem. But it may help. Food for thought.