Wow, at wits end here. Truck began dying after approx 5-8 mins on road. Just cuts off, and can restart. Pulled codes. Got a 33 14 and a coolant temp sens oor (dont remember the number) also got a thermactor code. Replaced the EGR Valve and Vacuum solenoid, replaced all of the small plastic vacuum lines with 5/32" rubber. Also replaced the EGR tube. Ran great, 33 gone, 14 still there. So, in past experience with my other 88, I swapped out the ICM. 14 gone. Coolant temp sens code gone (lol, unrelated) Drove 20 mins, great. Way to work this morning died at 35mph, fired up, died in a mile, fired up died in 2 miles, fired up, died in 1, fired up got to work 4 miles. Pulled code, (CEL method) KOER code 18. Question: my tumbler has been a bit difficult to turn all the way / get to "RUN" lately. Actuator is fine, could a bad Ignition Switch, (Under the dash) cause the stalling / Code 18? SPOUT wires are clean.

Thanks in advance!

 

OK, I see I didn't get any hits, but throwing a puzzling update. The truck has a misfire at 2200 RPM. open the throttle to 1800, it will be steady for about 5 seconds, then it ramps itself up to 2200 and then misfires (may not be the right term for what is happening) back down to 1800. Rinse and repeat. My buddy who is a tech ran the PIP waveform and I am getting a rounding on the OFF cycle. Swapped out the Dizzy last night and am setting the Timing this evening. Still don't feel it will solve it. Any thoughts on the RPM issue?

 

Sorry you got no feed back. Usually helps when reporting codes to post all the code definitions that you understand to be associated with the numbers recorded (Lots of different definitions). Folk more likely to help if they don't have to decode what you're trying to repair. Just sayin'.

What color ICM came out & went back in? Aftermarket or Motorcraft?

In re the RPM change, off the top of my head I'd look at fuel pressure & check the resistance in the TPS for giggles.

Good luck & hope you get more responses.

 

An EOER 18 would mean a lost of power to the Ignition system. So the Ignition switch is an item to check.

 

Good point Scndsin. Gray and gray on the ICM

Right now it stands as this:
KOEO 11 11
KOER 46 46

Previous:
12 Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) – ISC
(Replaced IAC code gone)
14 Ignition pickup (PIP) was erratic – Ignition Systems
(Once went away after pulling jumper during test to clear codes)
21 Engine Coolant Temperature (ECT) sensor out of range – ECT
(Replaced sensor code gone)
33 ALL – EGR did not open/ respond during test or if memory code, did not open intermittently
(Replaced EGR, broke tube, pulled plenum, replaced tube, new plenum gasket, still 33, replaced EGR Solenoid, 33 Gone)
46 Thermactor AIR Bypass (AIRB) not working – Air Injection
(Constant)
77 System did not receive “goose” test – see TESTS
(ID-10-T behind the wheel)

-I adjusted the TPS and got a very clean sweep from closed to WOT.
-Also replaced the lock cylinder and Ignition switch under the dash. Key hard firing now, need to push forward, back then forward to engage starter. Just need to adjust the Switch forward a bit I believe, I could be wrong)
-Cleaned TB spotless and checked all ports.
-Last night checked the MAP, clean sweep on frequency.

I think my intermittent stalling is in regards to the rpm since it seems to stall between 35-45 mph. Just dead, coast to the side. No sputtering.

Thanks for the response Scndsin and I feel honored to have Subford the post fiend add a reply! I'm rebuilding a 72 F250 300 I6 for my daughter who is jacked about it. I keep thinking I may throw that beautiful block and head in my garage, Just dipped, bored, honed and painted into my truck!! No stinking computer there.

 

Hey all, at this point I'm 5 weeks in and now I think Im chasing my tail, and possibly making things worse.

So, I broke down and called Ford Dealer and was told they will not and can not diagnose OBD1. Great. So, pulled my PCM connector and cleaned it, and for 5 days I had no stall. I developed a misfire, and found my Cyl 3 boot was loose, after connecting the next day he stalled. 2 things: I pulled the connector and cleaned the computer pins this time, applied a thin layer of Dielectric grease and reconnected. I had also jumped my inertia switch with a heavy paperclip, and it still stalled, so I pulled the clip and reattached. Next morning 3 minutes after start smoke from kick panel and massive stutter and he died. 6 inches of the brown (from FP relay) and pink/white (to Tank selector) were now welded together and fried along with the inertis switch connector melted. I now have no FP when turning the key. I cut, and checked continuity of both the wires, from my cut to their ending points, all good. My issue: I have 12V to the EEC relay and 3.72 coming out on the Black/Yellow wire (To FP relay). My FP relay has ~3.7 in on the main and 2.06 on the end of the brown wire which would have connected to the now gone inertia switch. I have 2 (new/store bought) EEC relays on hand and have tried both. Is this voltage reading in spec? I'm so far out of my realm of mechanic-dom, I can't even see the trees...

One last point. While fixing the burned wires, I noticed the loom coming in from the firewall went over and tucked behind the bracket for the e brake. Yes, The brown wire going to the inertia switch had about 1/4" of insulation gone. I know bare wire on steel may be a problem, but would that cause the above mentioned Wire-B-Q?

 

with smoke coming from the kick panel, my first move would be to remove the computer and open it up for a look see.

 

Sorry, I forgot to mention. I did that. Looked good, but that's when i found the inertia leads melted together. I went and bought a new computer anyway, and have that one in now.

 

If those leads are fried I would be looking at a bad fuel pump.

 

A big problem on trucks of this era is the wiring under the relays.
There is not a tank selector relay on a 1988 5.0L FI engine.
The brown bottom relay is the EEC power relay and a green bottom relay is the fuel pump relay.

A lot of posters with this era of truck have upgraded the relays to the newer relays used on the mid 90's trucks.

The diagram below shows this mod:

The new type relay is the top one below:


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