When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I think I understand. So the ICP is simply a monitor for the pressure, it doesn't directly do anything. The IPR is the work horse. IPR changes, ICP sees it and reports it. I think next step would be replacing IPR. Hopefully that addresses the no start issue. I see that RockAuto sells Motorcraft IPR. Being it is the branded valve, is this acceptable? It is $60 cheaper than the cheapest I could find elsewhere (as a Motorcraft anyway).
I think you've got it. Agree that motorcraft IPR from Rockauto should be a good one.
When you receive it, check the package the IPR comes in for spelling mistakes or other issues. The fakes we've seen have mistakes on the packaging text, like the following:
I would also replace the ICP sensor and keep old one in the glovebox.
I haven't seen any aftermarket "round" body ICP sensor,so it is good to assume that your's is still OEM.
I had OEM round style ICP (was working good)at 500k miles when i did my DIY injectors.Replaced with new Motorcraft when chasing Idle issues.
Good catch! I'm not sure why the offset occurs there. There should be very little offset from PID to PID in the log data (much faster than what we observe on the FORScan dashboard/gauge view).
Here is today's stall for comparison, and ICP drop appears to line up with the RPM drop. This data is not always as precise as we'd like - our experience with the symptoms is often as important, if not more so, to get to a proper diagnosis.
Yes sir, I noticed it wasn’t offset on the latest stall so decided the idea had no merit.
My guess is the rpm signal resolution made it show like that. Maybe just a sampling rate difference.
I think you’re getting to the bottom of this issue and always appreciate your analysis of the data.
I think you've got it. Agree that motorcraft IPR from Rockauto should be a good one.
When you receive it, check the package the IPR comes in for spelling mistakes or other issues. The fakes we've seen have mistakes on the packaging text, like the following:
Gotcha. I will order it and get it installed. Hopefully it helps! I was able to get the truck started today to move it back home so that's good...
Originally Posted by FinnishStroker
I would also replace the ICP sensor and keep old one in the glovebox.
I haven't seen any aftermarket "round" body ICP sensor,so it is good to assume that your's is still OEM.
I had OEM round style ICP (was working good)at 500k miles when i did my DIY injectors.Replaced with new Motorcraft when chasing Idle issues.
Gotcha, ICP is on the list! Thank you.
Originally Posted by cleatus12r
An open IPR usually only allows for 200-250 psi on a warm crank.
usually.
Understood, so being that with the ICP connected, it was only 150 psi, perhaps you agree with IPR replacement?
If it is IPR related, I see one of three failure modes.
1. The electromagnetic coil goes open (or high resistance) due to temperature and does not make enough of a magnetic field to move the IPR pintle to the closed position.
2. The pintle itself gets to a temperature causing it to seize in its bore (unlikely because it would stick at a more closed position making higher pressure).
3. Just ran into this issue on one a few months ago and finally got the loaner PCM back after 6 months. The driver (transistor) in the PCM for the IPR had failed and would quit switching when hot. The IPR runs on a 400-ish Hz frequency.....that's a lot of switching.....and it would quit grounding the IPR coil after a bit of running.
3. Just ran into this issue on one a few months ago and finally got the loaner PCM back after 6 months. The driver (transistor) in the PCM for the IPR had failed and would quit switching when hot. The IPR runs on a 400-ish Hz frequency.....that's a lot of switching.....and it would quit grounding the IPR coil after a bit of running.
The worst part for the guy is that it's the DPC-452 (50-state emissions for an 01 pickup or Excursion) and he had borrowed one of mine for what was supposed to be a couple weeks while his was being repaired. It turned into 6 months and I was getting really nervous about the prospect of losing $1500.
I got it back though and now it's safe and sound again in my faraday cage storage facility.
3. Just ran into this issue on one a few months ago and finally got the loaner PCM back after 6 months. The driver (transistor) in the PCM for the IPR had failed and would quit switching when hot. The IPR runs on a 400-ish Hz frequency.....that's a lot of switching.....and it would quit grounding the IPR coil after a bit of running.
Cody ( @cleatus12r ), what was your method of testing and diagnosis in order to identify the failing PCM? Did you try everything else and get lucky? Did you see something in a data log or chart that clued you in? Something else?
Full 65% IPR when cranking, 200 PSI. 12V to IPR connector key-on.
Jumper harness to IPR started right up.
Plug engine harness back in, no restart.
Easier to slap a different PCM in than to check wiring. Started and ran.
Plugged original PCM in, no restart again.
Swapped tester PCM back in and drove it all day........
Easy <10 minute diagnosis.
I have replaced two IPR drivers in 99-up PCMs over the years from being dead. I haven't done a 94-97 though (have one on the shelf) because it's a really special part vs. the newer ones that are Digi-Key standard parts.
I have a 2A fused jumper wire with alligator clips that goes right to the battery. The longest the thing is ever hooked up is 30-45 seconds - not enough to hurt anything electrically - and it only has to start and run for a couple seconds at max pressure.
Good morning everyone! Sorry for the delay in posts, I was gone all last week. While I was gone, the IPR came in the mail and I replaced it yesterday. Initially, ran extremely rough but attributed it to having air in the system. Drove it for a bit and it smoothed out exponentially. I drove it farther than I have in the recent past with no issues! No stalls at all (crossing fingers...). I have attached the data gathered since I have it. While I was in the area, I decided to put a little elbow grease in cleaning up the valley of all the oil that was in there. I found this nut just hanging out in there. I am thinking since it is "fancy" that perhaps it is the nut that used to hold on the plastics?
The remaining things regarding this situation is still to replace ICP since it has oil in the electrical connector and resolve whatever is causing the oil leak because after one drive it was already filled with oil...No idea where to even start with the oil leak.
04-26-2023, 01:31 AM
