I may be conversing with myself, but so be it, it helps me think to type it all out, read at your own peril.

First I will clarify a few items... Im in the middle of Florida, pretty warm here lately!

88 Club Wagon XLT 7.5L (TFI ignition system... NOT Duraspark II)

Only five sensors going into the EEC computer... (KS only in 5.0L)

Suspects....
1. Throttle Position (TPS, very top of the intake manifold on left under dashboard)
2. EGR Valve (EVP, found next to your right knee)
3. Manifold Absolute Pressure (MAP, no idea where it is! Right knee again maybe?)
4. Engine Coolant (ECT, top center front of engine intake manifold, left of distributor) - Recently Replaced
5. Air Charge Temp (ACT, behind distributor top center) - Recently Replaced
6. Computer Controller (EEC IV Module - Passenger foot well, 10mm socket for the connector)
7. Ignition Module (bolts to side of distributor, feed by the EEC)

To review, the ECT was a certain fix about a year ago, I literally changed it and was able to drive 300 miles non-stop with no trouble. After being is dry storage most of the year I drove the van about 1100 miles straight with no trouble, and then the symptom came back. changed the ECT again, no change this time, changed the very dirty ACT as well and no change.

So the van starts pretty good when cold, will not die for quite a while or about 15-20 miles of around town driving. When it stalls it cuts out and stumbles, I can usually nurse it along at that point (via throttle jockey) a few blocks or more before it will just die out. It will not restart until 10-15 minutes of cooling, then im good again for another couple miles before it repeats.

The problem is very steady, it always does these things like above, this leads me to believe it is not a bad ground or wire or else the issue would pop up at more or less random times. I have changed the fuel pump several times in the years I have had the van, even dropped both fuel tanks, cleaned them out and replaced all fuel pumps and hoses etc. in the last two years. While the fuel injectors themselves have not been out in my time with the van, I fail to see how a bad one or even two injectors could stop the engine. I don't think FUEL SUPPLY is to blame.

The IAC valve, spark plugs and wires, cap and rotor all nearly new and things look fine under the cap. I DO have a annoying miss most all the time, gets worse with heat, but it will idle at a light and does not stall... until the most recent troubles cropped up that is.

Because of the repeat-ability of the problem and the way the bad ECT sensor affected the issue very clearly, I think the EEC is to blame... but because of the sensors or the computer itself ? The 64,000 dollar question !

Sensors are cheaper so lets start with them... of the five sensors that input into the EEC I have changed two in the last couple days. That leaves the MAP, EVP and TPS.

The EVP is just a device to inject a bit of exhaust back into the combustion process, I cannot understand how this can be at fault and smother the engine to a stop in any type of failure.

The TPS is just a variable resister on the throttle body, its certainly possible this could overheat and open circuit, but if that's the case why does the problem act exactly the same as the ECT failure. Have to leave that as a possible maybe.

The MAP sensor is a measure of the Manifold pressure, its output is a square wave based on the pressure in the intake manifold, more air equals more fuel. This item is not likely to cause an engine to die even if faulty... it may be the trouble with my idle, but can't see it stopping the engine. Again a possible maybe.

Today while having the trouble around town I paid attention to the EEC, I pulled it out and checked the plug and pins, peaked inside to be sure its not full of water or corrosion, all looked good... but it was pretty darned hot. It is located in the passenger foot well inside the cab, what should be a pretty cool place. So I tried to cool it off and see if it would give me less problem time, (quicker restarts) this was inconclusive.

The ignition module I think is the target as I think about it tonight, its right at the top center of the engine getting all the heat from the engine as it is almost bolted directly to the block and heat is the enemy of all electronics. Its not terribly expensive at about $50 as well.

Next problem... A BIG ONE, the distributor is frozen to the manifold! To change the module it sure looks like the dizzy has to come out because of clearance issues with the bolts. I have never had it out as the electronics keep the timing in shape so no need to set the timing and keep it unfrozen.

The dizzy and manifold have be intimate for far too long ! I will soak the thing some more with Mouse Milk but don' t know what to do here. Because of the access issue, I have to think the module has not been changed in quite some time. I certainly cannot afford to break off the dizzy, which looks pretty easy to do!

Tomorrow when it stumbles again, I will try to cool the module off and see if that changes the ability to restart and drive more quickly, that could be some good data.

Anyone have anything constructive to add ??

 

I think you should read into these links -

https://www.ford-trucks.com/forums/9...tor-issue.html

Or do a search with this - "ignition module relocation"

Kind of what you wrote in your 'bold' statement above thinking your having heat issues with the ICM.


Stuck distributor, been there........I've cut blocks of wood to fit under the bell of the distributor, setting on the block, and using a pry bar, popped the dizzy straight up and out

 

update....
I went with the remote Ignition Module, found a old PC heat sink, got some premium heat sink compound from radio shack, and mounted a new module right up front just behind the grill and in front of the battery.

I replaced each wire one by one so as to not get them mixed, and covered the two signal wires with foil and wrapped them up good.... then I learned something. When I was all done I had wrapped all the control module wires together and ran them to the new location, plugged it in and... no joy! Would not start!

Eventually found that the two signal wires and the ground return bare wire do not like company. When together with the other wires things are not happy, so I divorced the two sets of wires and ran them different routes to the new module. Runs mucho better !

The acid test will be some around town driving in the morning, get it hot and see if Im fixed (again) fingers double crossed.

 

I have driven well over an hour since the remote module change, seems good for the most part. I did have one stumble and stall out, but once again I moved the module signal wires away from others it fired right up. I see by the schematic that these shielded wires run all over the engine compartment... dizzy, module, alternator, ignition switch and more.

I still have a bit of a miss at idle and it seems to be sluggish a bit more than I like when accelerating, but is livable for now. Huge test next as I take off on a 1000 mile drive in a day or two.

I have checked the OBD1 codes, all I get today is "Fuel pump primary circuit failure", but of course I doubt I could drive around an hour with that failure. What is a primary circuit anyway ? The coil side or the high current side? Or another path for the relay coil ?

Wish me luck, thanks all.

 

Quick update, the van runs great, 1500 miles no trouble.
Highly recommend the remote module mount !
I did replace the EEC and Fuel Pump relays with fresh units just to be sure.

Next is the real 'real' test, fully loaded and flat towing a 3000lb car.... 1000 miles.

Merry Christmas to all !

Reminds me of a song.... "2000 Miles" by the Pretenders

 

Hi Mazoomda,

Thanks for all your posts. I seem to be having a similar issue with my 1988 Ford E350 RV. Stalling when hot outside but not necessarily a hot engine. Wondering if you can confirm that you have a permanent fix? Changing the ICM was actually the first thing I did but I never moved it away from the distributor. I have since swapped out various other sensors with no luck. Wondering if it is in fact the ICM and maybe I just need to move it to a cooler place?

Thanks!

 

^^^It might be a long shot whether Mazoomda replies--this thread was last updated almost 6 years ago.

 

Used to test the modules at Ford with a heat lamp (makes them die quicker)
Simply replace yours and the stator too
Plan on replacing the distributor
Put a new oem ford stator in any new china distributor you get
A working duraspark ignition tester is getting hard to find even at ford dealers

 

Thanks for the info. When you say heat made ICM die quicker do you mean die permanently? I can always start up again after about 45 minutes of cool down. It almost seems like vapor lock to me because the problem is transient and clearly linked to outside ambient temperature but it is fuel injected so not sure how likely vapor like would be.

 

Lots of expertise has chimed in but in an non Ford I had, difficult hot restarts was caused by a failing crank position sensor. In these vans it might be part of the distributor.

Have you checked for spark and fuel pressure?

Sixto
07 E350 5.4 178K miles

 

The “remote mount” of the ICM is a must, I moved it to behind the grill attached to a computer CPU heat sink, have had zero issue since.

The shielded wires took a little while to find a happy home where they would not cause a stumble. My harness is covered with foil tape and routed away from the rest of the harness.

The coolant temp sensor also is important to ensure the computer gets a clean temp signal, had these go bad a few times.

be sure to have spare main cube relays, they are cheap and can cause start issues.

My van has been very reliable since these main items were taken care of, amazing reliable for an old van, I pull away from everyone at a green light. Torque Baby.

 

The other big item I have found about stumbles is to ensure the fuel pumps are in good working order. This can be trouble until you find a good quality fuel pump that will run and run, the lift pump in the tank is important, both need to work well, very well in such a thirsty engine.

 

I have not yet checked these but I will. Someone else suggested crank position sensor so I will add that to my list.

Thanks!

 

All very helpful, thanks for all the input! I suspected failing fuel pump as well. I plan to swap that out. I'll redirect the ICM to a cooler place and heat shield as much wiring as I can. Coolant temp sensor has been on my radar as well. I'll try it all and keep my fingers crossed. My issue really seems to be dependent on outside air temp. Oddly I had possibly a faulty thermostat that was causing my engine to run on the high side of normal. Hotter than it had ever been before but the outside air temp was in the 30s. It ran like a champ under those conditions. Later on I pulled the thermostat out and engine temp was very low side of normal but outside temp was 85F. Then the stalling issues began again. So definitely seems to be linked to outside air temp. That got me thinking intitially that the problem was separated from the engine (so possibly fuel pump). But could just be a sinister coincidence so I'll try all of the above

Thanks again!

 

Heat lamp and the Duraspark modules
They never died permanently
Each time they cooled down they would restart and run
Problem is they would strand you when they died and you would have to wait several hours to restart the car
Our heat lamp test was just to verify it was the module at fault
A new module would fix the car from dying