I've had an issue with this vehicle where it would either "sigh" or miss when hot for a long time...now it's turned into a full on stall- comes out of nowhere...

Here is a list of things I've done- based on extra parts lying around or things I found wrong:

Reman ECU- replaced after opening my old one and finding 3 caps all leaky and who knows what is wrong with them (seen other threads out there about these ECUs having leaky caps)- the Reman ECU had the same problem BEFORE being remanned...not sure if that's fixed or not- I'm trying to find another ECU with caps that don't look like the kind that leaked/failed...

Swapped 2 different IACs - same issue - had IAC lying around...

WAS throwing code 565 for the Purge Canister Solenoid- replaced with new, code gone...

Swapped between 3 different ignition control modules...same issue (had these ICNs lying around as well...)

I have a new distributor on the way- and will swap that in later today- maybe PIP signal is getting lost- not sure how to test without oscilloscope... This part is owed to me in exchange at O'reillys for another bad distributor that locked up from another truck...I'd really like to test PIP signal or signal loss or whatever before I throw another part in the mix...

MLPS changed to a motorcraft from aftermarket one- original and pigtail changed out when issue of high speed gear drop out was noticed...this problem went away, but considering the miss I was having, I decided to replace the aftermarket with a motorcraft one...problem has only progressed since adding the motorcraft part in- but maybe coincidental based on another part or connection or whatever getting worse...

Tested fuel pressure...hangs around 29 till you goose it, jumps to around 35-40 and levels out again at around 29...doesn't seem like starvation- just stumbles and dies, OR just actis like you turned off the key...starts right back up...

Throw me some wild guesses and or some recommendations of test procedures...

If I didn't know better I'd think this reman ecu isn't really fixed...

THANKS!

Dave
93 E350 Clubwagon XLT E4OD

 

Check this:
https://www.ford-trucks.com/forums/1...l#post14740314

 

Thanks for the post...I watched the Eric the Car Guy video...and will be trying to run through the procedures in that thread, too...

Another side note is that I have recently replaced the alternator because the old one had swinging voltage..wondering if that could have messed up anything- engine computer or otherwise..it never went higher than 14.9, but man, that seems high...

Thanks again...

Dave

 

I doubt 14.9 would hurt anything, Dave. The ECM regulates sensor voltages to 5V in case the battery voltage drops below 12 volts, and has overvoltage protection. The PIP sensor OR the wiring to it could cause the problem. Tugging on the harness while it is running might find the problem. jim

 

Man have I been wiggling...but will continue to...

The prev van this engine was in had a similar PIP problem which turned out to be a bad part of a wire...wiggle made it work, wiggle made it not...we repaired the wire...

thanks so much for all of the help!

Dave

 

New ECU (reman with same replaced 3 caps) doesn't make a lick of difference.

I did notice that it is like clockwork...I measure the coolant temperature with an IR thermometer at the upper radiator hose...Once it reaches about 160 (from the outside of the rubber hose) that's when it falters and within about a minute it stalls... Ambient temperature in the 70s it takes 12 minutes from "cold" (radiator hose reads 85) for it to completely die...

I did so much wiggling around problematic areas (areas I think would be problematic...)

I decided to measure ohms reading on the ECT for kicks...reads in spec at about 2800...

Vacuum steady @ about 18 until it dies...

Pulling my hair out here...Will probably go get that distributor sooner than later...but I'd really like a diagnosis...if it didn't run at all it might be easier (?)

Thanks for all of the help!!!

Dave

 

I had the brilliant idea of running this with the lights off...

I had an arc coming from a previous installation of a tach tied into the coil...I'm wondering if that created a bad connection in that wire- I'm going to buy the pigtail and create a better connection.

At least I am one more step closer?

Dave

 

I think you may be onto something, Dave. The 160 temp is also where the ECM goes closed loop and starts using all the sensor inputs. May or may not be an issue. I'm still going with bad connection for now.

I do prefer having a totally dead vehicle to an intermittent problem... as long as it is totally dead sitting in my shop! Ha
jim

 

Thanks, Jim...

So I can definitely find the correlation between heat and this thing shutting down...it also changes the idle to an idle that is way low...don't have a tach, but seems TOO low for my comfort...

I taped the wires to the coil- I'm assuming no more arc- but alas...same stall @ idle- it has in the past run a little rough before it did it, but not this time...

Can O2 sensor have anything to do with this? I had previously changed the O2 sensor within the past year with hopes that it could have had something to do with the random miss that this had been having for eons...

Thanks again for sticking with me...

Dave

 

Next step is to install the new diztributor...I exchanged a seized one from O"really" last night so I figure I have not much to lose here...

Dave

 

Here's a quick check, unplug the O2 and drive it. Won't hurt anything, the ECM just uses stored values in the fuel map, and your fuel mileage will suffer but it should eliminate the O2 as a problem.

I had an 86 302 Mustang, speed density EFI, with a Ford recall to replace the cats. O2s were not part of the recall so when the system hit closed loop with new cats and old sensors, it ran like half the plug wires had fallen off. I unhooked the O2s (dual exhaust) and it ran great but very rich.
jim

 

Hey Jim...

Thanks for the reply...great minds think alike..

Since I already had a warm (failing) engine...I decided to throw a couple other things in the mix before tossing in the new distributor...

The MLPS- albeit probably not related at all- I swapped the old one back in...same problem
A known good coil...same problem
Unplugged O2 sensor....same problem

What puzzles me is that the injectors keep firing right up until the stall- I can feel the pulse on the fuel hose...when it sputters before a stall the engine speed AND the associated pulse slow down as well...I really think it's getting PIP signal...it correlates to the speed of the engine AND fuel injector pulse...also for grins last night I put the pressure tester on there and it held a solid 30-31 all through the entire sputter stall...sounds like fuel pressure regulator is working just fine...it pulls up when you goose it, etc...

I have yet to back probe the ICM to get the PIP signal because of it's location BEHIND the battery- I may do that before replacing the distributor. I really want to see a failed test before I replace a part...even though I own it :-P

I won't be able to work on it until later today/tonight- I'll post my findings....

Dave

 

You can get to the PIP harness from the distributor, there should be a connector in the harness close by.

I totally understand finding the problem before shotgunning it. Just gotta know!
jim

 

I actually was able to get to the PIP on the ICM and the distributor harness...checks out @ about 5.9-7.1 V while the engine is running...little to no change during the stumble...and I didn't have enough time to wait for it to stall- suffice to say the engine temp was pretty close to where it should have been to stall, but didn't :-(

I'll try to test the ICM later with test lights...but I'm pretty sure PIP is pretty good here...again, why toss this other dizzy in there if I don't NEED to..

Now I'm almost run out of ideas of things to check...I will keep poring over wires to see if I can find any chafed or whatever...but...this almost seems like something is TELLING this thing to shut down...or idle way way down...wondering if it could be that I have a couple bad IACs...no idea....

Dave

 

Forgive my ignorance on this engine's ignition system but any way in hell the timing chain plays a part in all this? Could be cam itself contribute?