7.3 cylinder 3 contribution fault nightmare.

Bustedknuckles · Nov 4, 2016

I was chasing a cylinder 3 contribution code that would sometimes move to cylinder 5 and loud slightly rough idle on a 7.3 after a engine rebuild and new injectors and finally got it fixed. I ohmmed the wiring, swapped injectors around, put in 2 new cam sensors from Ford, did a cranking and running compression test , swamps IDM, ohmed all the wiring, new tuning, new uvc harnesses, graphed iniector firing patterns with a lab scope, etc etc and finally told him he was going to have to run it through the shop as i didnt have time to work on it in the evenings any more. He took it to a friend of mines shop since it was closer and he re-did everything i did plus measured pushrod travel, swapped engine harnesses with a known good one, put a cam sensor out of another truck in and put clear fuel line on the return to check for air bubbles. After striking out on all that he ended up getting a cam sensor from Advance Auto Parts and it is fixed. Just thought I'd post this for anyone else who runs into this issue!

gnxtc2 · Nov 4, 2016

Besides the fault code, how was the motor running?

Billy T.
[email protected]

Bustedknuckles · Nov 4, 2016

gnxtc2 said:
Besides the fault code, how was the motor running?

Billy T.
[email protected]

Very slightly rough but with a pretty obvious knock/rap.

D66stroke · Nov 4, 2016

I've been chasing this problem on my 97 since I bought it 2 years ago. I've thrown money at it replacing everything without a fix. Finally had a friend OHM out the harness and traced it back to the IDM, swapped IDM with another truck in the yard and it got smooth for a week or so. Sure enough this fuel knock/rough idle is back.. I've tried a new Ford ICP and pigtail, IPR, IDM, like 3 different International cam sensors, etc.. About to run to Advance..........

DEEZUZ · Nov 4, 2016

We have 1 of these too. But it happens so in frequent we can never data log. It comes in once a month, lol

TARM · Nov 5, 2016

Look back thru the CPS threads. A few of use did tons of testing broke open CPS etc to find the one/s that work best. WHat you are looking for is one with a the strongest magnet and that its perfectly centered in the case.

Another thing we found that can send some CPS crazy is the wiper motor. Of all the stupid things they set the wiring up to share the same common ground. Thus dirty electric off the motor can screw up CPS. Answer you can find a CPS that does not effect it replace the motor or give the motor its own ground.

I can not name the CPS brands off the top of my head but look back 12-18 months in the forums its all there. But IIRC I got the ones thru Advance Auto.

DEEZUZ · Nov 5, 2016

Yea, I think you and Woodnthings did some great research.

gnxtc2 · Nov 5, 2016

TARM said:
Look back thru the CPS threads. A few of use did tons of testing broke open CPS etc to find the one/s that work best. WHat you are looking for is one with a the strongest magnet and that its perfectly centered in the case.

Another thing we found that can send some CPS crazy is the wiper motor. Of all the stupid things they set the wiring up to share the same common ground. Thus dirty electric off the motor can screw up CPS. Answer you can find a CPS that does not effect it replace the motor or give the motor its own ground.

I can not name the CPS brands off the top of my head but look back 12-18 months in the forums its all there. But IIRC I got the ones thru Advance Auto.

http://www.powerstrokearmy.com/forums/showthread.php?t=43949

You want a black CPS like the one mentioned in the thread.

You want a Delphi HTS101G <---- must be "G"

The Standard PC603 is a crap shoot, post #140

Billy T.
[email protected]

TARM · Nov 5, 2016

And there ya go. That is the CPS EVERYONE should be running IMO.

For anyone just curious when they need one. Pull your old grey "ford OEM" one and this one. Lay a few heavy bolt nuts on the table and see which one picks up the heaviest nut.

FYI This issue is not just for 7.3s you can see the same nightmarish crap people go thru with issues on the 4.0 jeep and I am sure all manner of other engines. ON the jeep its the CPS but stands for crank pos sensor Sits in the bell housing and works the same as our CPS does in terms of how it functions i.e magnet hall and pickup. People all over the place get auto store crap and they end up with all sorts of mis fire limp mode cutting in and out etc issues. Some people spent thousands of $$ rebuilding heads replacing all manner of stuff. Go on any jeep site and you will see hundreds of threads that most are all crap made CPS. In this case they need the MOPAR one and all is well. 7.3 are one of the few cases where the rule of always buy OEM when it comes to sensors and electronics does not hold true in this specific case. Case where Ford IH took a MINOR PITA long existing issue and turned it into a Custer!@#($U#RJE Before we found this CPS how many would kill to have back the short lived OEM black CPS LOL :morons:

co04cobra · Nov 6, 2016

I would kill to have the old black ones back.

I can't seem to find the Delphi one with the "g" actually for sale anywhere.

If someone does please post a link.

gnxtc2 · Nov 6, 2016

It appears that the Delphi HTS100 looks like the HTS101G.

http://partcat.com/delphi

Do a part number or vehicle search on Delphi's site

Billy T.
[email protected]

DEEZUZ · Nov 6, 2016

I tried to run a black one and all that happened was I'd die out when coasting. I've had an Alliant power Grey for 6 years now and no issues. Not sure whose their reboxing though. Probably Delphi

TyCorr · Nov 6, 2016

Alliant stuff has been junk for me for the last 5 years. Went to Midwest diesel injection as they are local to me and have super low prices. Ordered uvch and they were made in effin china. The cps i got was too. I went to international trucks shop and ordered and the stuff was usa made. Including the grey cps. I have that grey one in my truck still but have 4 good black cps in my toolbox. Im just too lazy to change it as my truck runs fine as is.

DEEZUZ · Nov 6, 2016

Alliant is like 80% reboxed units from OE.

TyCorr · Nov 6, 2016

Be that as it may i must be getting the 20% that is foreign junk. I have seen motorcraft stuff with "made in china" on it too lol. So the cancer is spreading. Ford hasnt given a ***k about part support on these trucks for 8 or 9 years now.

D66stroke · Nov 6, 2016

So basically all these posts I've read over the years saying to NOT get a cps from advance, autozone, etc.. Should be the complete opposite now? Or am I misunderstanding this? I've replaced cps with both the grey and dark blue without a fix (the grey smoothed it out for the first 20 minutes after install..?), the dark blue being the most recent and no change. So pretty must this Delphi###### cps is the fix to this rough idle/fuel knock?

D66stroke · Nov 6, 2016

I'm just saying this truck has idle'd like sh*t, along with the injectors being abnormally loud when driving, since I've owned it. My previous 97 was smooth as can be. This one you can't even hear the exhaust over the engine

ghohouston · Nov 6, 2016

I've had good luck with the delphi black hts101g's. They have a larger magnet on them. I believw someone told me a while back delphi was who made the original black cps's, but dont quote me on that.

co04cobra · Nov 6, 2016

ghohouston said:
I've had good luck with the delphi black hts101g's. They have a larger magnet on them. I believw someone told me a while back delphi was who made the original black cps's, but dont quote me on that.

That's what I'm gathering from previous posts, but now I can't seem to find the hts101g for sale. None of them have the (g).

I know about every other aftermarket one out there I have had to replace for all kinds of stupid reasons.

And the ford updated ones can and do give all kinds of screwy ccts, rough idles, extended cranks, etc..

D66stroke · Nov 6, 2016

No luck here either. Kinda sucks having to scramble around to find a sensor, you would think this issue would have been fixed by International/Ford by now being that it's just a sensor. If I remember right I ran a 466 CPS awhile back in my previous 97, don't think I had any issues. I want to say they are expensive though