[Maryland dieselnick]

I have tried all the CPSs I could find.
I found this NAPA ELCHINs model and it's awesome.
I did have issue with it killing engine at idle only with wipers in the intermittent mode with it raining and then again with testing with garden hose.
I corrected this with ferrite chokes.
First things first.

 

[Maryland dieselnick]

This is the crank rotation velocity change report.:rocker:

 

[Maryland dieselnick]

This is the cylinder contribution test report.:thumbsup:

 

[Maryland dieselnick]

The choke beads are simple clamp on beads I got from Radio Shack.
First I tried the CPS ground, positive reference feed and signal as seen below but truck shut off after fifteen minutes with wipers wiping garden hose water or mist combinations while in the intermittent mode.:ugh:

 

[Maryland dieselnick]

So I remove drivers side wiper arm and the bezel below the arm.
I cut open wire harness to motor that is pictured here and place a choke on each wire and then one larger over the entire bundle of wire. I then taped up wires and chokes with electrical tape and then coated with Plasti Dip.
I then zip tied two ways as moving arm can rub against it.

 

[tinman13kup]

Why are cps's so friggin difficult? It seems all the "new and improved" ones have issues. I had to buy a new cps from the local parts store (BWD) and it advanced the injectors to the point of trying to skylight a piston above 1800rpm. i thought it was a fluke, but another guy I know with a SD said he had some issues (bad idm in the end), but initially replaced the cps (as I told him long ago) with a BWD and had the same problems.
The black one's were just fine. Why fix something that isn't broken?

 

[Maryland dieselnick]

I then sprayed mist, sprayed heavy water, as well as let it wipe dry.
I repeated this test on EVERY increment on stalk for fifteen minutes.
I also tried spinning mode selector back and forth.
Well after an hour I declared victory as I could not kill it.
I took it on 3.5 hour trip to beach and it drove like a dream. It is quieter,smoother and just plain sweeter.
So I don't know If I caught the wire carrying the interference on the second attempt or if I created an accumulative effect.
It is not a lot of work and the small size chokes are in two packs for $2 and change.
The larger I used to cover the whole bundle is this guy and was about $3 and change for one.
Disregard the scrap of wire pictured next to it.
I hope this helps you benefit from a great running engine and gets rid of that bad feeling you have not passing the CCT test and just plain knowing your truck is not running the best it can.
Take Care
Nick

 

[Googs]

Good thread Nick thanks for sharing that, you could do some resurfacing on that work bench mate.:lol::lol:

 

[Maryland dieselnick]

You don't like my chic coffe table?

 

[Googs]

I love it mate , just don't tear the table cloth on the surface .ha

 

[blue99stroker]

I need to go get some ferrite chokes. ive been using tin foil and its worked but I just never made a trip to radioshack haha

 

[Maryland dieselnick]

Call before you go. They seem to have less and less of that stuff and more toys and phones.
Times are a changin.

 

[blue99stroker]

ya we have two or three in town so hopefully one of them has them. ya last time I went there they looked like a cell phone store lol

 

[hucorey]

Nick, have you heard of the latest oem CPS update. I heard its dark purple now. Supposed to be accurate as the old black one, but reliable like the grey one.

 

[Googs]

I don't think it's reports to good Corey.
Its the dark grey blue purple , Part number 1876736c91
The 1876736c91 is for the 94-96 7.3L engines. It is also sold as Ford P/N F4TZ-12K073-C.

 

[klhansen]

Good info Nick

Thanks for posting it. I have a BWD CPS that I tried for one day in the rain. It was a total POS. I may have to try the choke trick and go back to my original CPS that was cutting out on me intermittently. Maybe the choke will make it more reliable.

 

[blue99stroker]

ive heard of guys having wiper issues with the originial cps as well. they recalled it so long ago seems like we all have high miles now. :lol:

ya it definately is not fun driving in the rain with it causing issues

 

[Googs]

Well i suppose the time will tell how these CPS's go in 7.3's
Are you guy's that have them installed hanging on the edge waiting for the truck to hiccup.

 

[SuperDutyTrooper]

Nick, Your write up is great, but I'm unclear on exactly what chokes you used for this repair. Did you use the same pair of chokes on both the CPS pigtail and the wiper motor wire, and are the ones in my attached pic the ones that you got from Radio Shack?

And what do you mean by "The larger I used to cover the whole bundle is this guy and was about $3 and change for one." . . . seems like there is a word missing.

Thanks for a solution to this annoying CPS problem!

 

[NYB]

How many wraps are you running through the ferrite bead?

I wouldn't think that the existing wires have enough length to run any wraps at all?