My '93 F-150 is having issues running. It all started a week ago. Aside from a fuel pump going out suddenly in February, it has had no issues starting, running, shifting, driving, etc. I normally drive with the OD off unless I'm on the highway. But, a week ago on the way back from a short trip to town, it started stumbling and running rough. It finally died at the next stop sign. It started right up but was running rough. Luckily I was a half mile from home, and it stumbled home, stalled when I stopped in the driveway. I fired it back up, made a quick knocking sound at startup, then idled rough, going from 2 or 300 RPMs up to 6 or 700 RPMs. No CEL at this point. Went on vacation the next morning, came back today, started it up. Fired up normal. Drove it around and after about 5 minutes, it stumbled and died coming to a stop sign again, this time CEL came on. Started it up, limped and stumbled it home. Don't have fuel pressure gauge but had wife turn key on with shrader valve down, fuel sprayed out like crazy. Pulled codes, came up with these..
654, Not in "park" during KOEO test...it was in Park.
634, Manual Lever Position Sensor voltage high or low, or AC on..AC was off.
631, OD Transmission Cancel Indicator Light circuit fault.
626, Coast Clutch Solenoid circuit fault
332, Insufficient EGR Flow detected.

I am wondering what direction I need to go to get this repaired. From what I have read, the EGR code wouldn't make it stumble and die like it is. The transmission codes worry me more than anything. I know I should probably get a gauge and check fuel pressure to confirm, will probably do that after work tomorrow. Has anyone else experienced this or have advice on what to do next? I appreciate it.

 

The last part of the second page of my thread here might help:

https://www.ford-trucks.com/forums/1...tor-valve.html

 

Last night, I removed the EGR valve and exercised it. I'm not sure if it was stuck or not, but I just got back from a quick test drive. Not once did it stutter, hesitate, or stall. I'm not calling it fixed just yet though, and I'm still leery about taking it too far from home, although I was encouraged. I would still like to confirm fuel pressure, I just have to get a gauge. Do you think it was coincidence that it ran good today or could the EGR have been sticking and all it needed was loosening up?

 

I checked the fuel pressure today. When the wife turned the key on, pressure went up to 40-45 psi, then slowly bled down over the next 15 or 20 seconds to around 20 psi. When running, the pressure was close to 40, maybe 38. So I went for a ride, drove it for maybe a half hour. Never had a single issue. Came home, let it sit in the driveway for a half hour or so, went for another drive. This time, it started stumbling and dying, same as before. On the first drive today, I was taking country roads, mostly between 45 and 55 mph. On the second drive, I went into town and after driving between 25 and 35 mph for less than a 2 minutes, it started acting up. Went home, had to restart it multiple times on the way, stalled again in the driveway. Started it up, at idle it was surging between 3-400 RPMs and 7-800 RPMs. Fuel pressure was surging between 36 and 39 PSI. Shut off engine, performed KOEO, no codes (111). Started engine, performed KOER, no codes (111). Am getting a little frustrated, and don't want to just throw parts at it. Anyone have any idea what could be causing this?

 

Well I know it's been a while but I believe I fixed my problem. Truck had been put on the back burner for a while (work, lake trips, trip to Moab, more work), but I finally decided to figure out why the truck wasn't running right. Did research, checked vacuum lines, found one leaking to EGR valve, thought that might be it..not it. Changed coolant temp sensor as problem seemed to occur when warm and others had similar issues..not it. Then one day a neighbor was walking by as my truck was idling real rough, said it sounds like its starving for fuel. Then it dawned on me, fuel filter! Changed it out last night, drove it for an hour or more, no issues. Drove it around for another hour today, still no issues. I'm quite optimistic about it now. Brings me back to what one of my Caterpillar instructors said years ago, Keep It Simple Stupid!