The tech: 1989 Ford F150. 5.0, auto, 4x4
The problem: Truck is cutting out. Seems to be a problem once the truck is warmed up, more under acceleration, or "load". Truck will cut out/sputter. Most of my driving is to work and back, which is only a 4 mile drive in the city, and it may or may not happen, and if it does, just once. Couple weeks ago I made a decent trip, 30 miles on the highway, and I didn't think the thing would make it. Cut out more times then I can count, acted like it wanted to backfire. When it's not sputtering it runs perfect, and at times, it ran fine down the highway. I've had the truck a month, bought off ebay, and drove back from Iowa, where it did it on and off. Seems to be getting worse.

What I've done: Checked the plugs and general tune up items (plugs, air cleaner, etc) and they are fine. Replaced the fuel filter. Just got around to picking up a code scanner and got the following results:

key on engine off: Code 14 (c), which is ignition profile pickup failure, circuit failure, engine rpm sensoer circuit fault. (from continuous memory).

Did the timing check, advance check, and it checked out fine.

Key on, engine on: Code 13 (r), which is a rpm at idle out of range, low.

All I have done so far is take out the idle air control sensor, cleaned it, and tested it. I had the right voltage readings in, but hte haynes manual says I should have a ohm reading between 7 and 13, I have around 5.5. Checked the sensor on my 87 F150, which is newer, and it had the same ohm reading. Two bad sensors or is the haynes reading not quite on???

Suggestions/tests I should run next? Motor was a new long block 25k ago and runs excellent outside of this. Really need to fix this little bug.

 

I have checked my two spare IAC 's and they are 9.3 & 9.6 and on my truck 9.3 ohms.Can you check your meter on a known resistance. Sounds like ignition code 14 is setting the code 13.More of a guess. Wish I could offer more but I have no experience in the ignition pick up coil area.

 

I should just need to pick up a resistor to verify ohms, correct? The meter I have is brand new, just brought it home, always a possibility it's off. I'm considering just going to look at a new one and testing it before I take it out of the store.

I thought the same about the code 14 setting off 13, but I haven't been able to find a resource that breaks down the codes with suggestions of remedies.

 

I hesitate to give advise on electrical as I am very weak in this area. I would think checking your meter with a resistor of a known value is the easiest way to check it. Since both your IAC's are getting the same value I would check the meter before buying new parts.One thing if you have a two way radio in the vehicle and the coax is near the computer wiring it can give you a code 14. Something I came accross in in one of my manuals.Is the meter digital?Remove the connector from the ignition module and check for dirt or corrosion.The area I would concentrate on would be the pickup or ignition module .These parts can give you the intermittant problem that you are having.

 

The meter is digital, and I have nothing in the truck that would be throwing it off. I'll check out the ignition module and such tomorrow. Thanks for the tip. This is the first time I've really dug into a fuel injection truck, so it's quite the learning curve.

 

The best way to figure stuff out is to do what you are doing.Getting your hands dirty , buying some basic test equipment, check some things out and after a while you will start to get comfortable with the whole thing.

 

lol I've got a garage full of tools, I'm just used to the carb'd stuff, where you've been around it forever, and whenever something isn't quite right, you pretty much can figure out what it is with little troubleshooting. My purchase of the multitester was because my old one got backed over in the garage.


Just for reference, they don't hold up well to being run over.

 

Sounds like two problems, mostly unrelated.

First, easy fix. Computer says Distributor Position Indicator (pip) this is just a hall effect sensor on the distributor(aka dizzy here) that tells the computer the engine rpm and firing position.
Mine went out and it did the same thing. It seemed to stall out more when I was really in a hurry, like being late for work... It was like having to sit in the penalty box on the shoulder but 5 minutes later it would start right back up and run fine till it switched off again.

To change it you have to pull the distributor. Mine was 20$ for the pip or 75 for a new distributor. I had to use a puller on the drive gear to get it. The biggest pain will be resetting the timing. It would be a good idea to check it before you take it out. Don't forget to pull the spout plug first.<<very important

I would wait on the idle till you fix the stall. Idle problems can be tedious, and the pip could affect it.

 

Thanks! I'll give that a try today. Nothing I've seen said anything about a Pip sensor, I need better resource material...

 

Just an update:


Think the problems is fixed. Went to get the part suggested and the guy was clueless, and basically, so was I. Figured $100 for a new distributor and ignition module wasn't really that expensive, and even if it wasn't the issue, can't hurt to have a new distributor, right?

Swap was easy and a drive up around on the highway didn't reveal the stalling issues. Came home and pulled codes and everything checked out aok. Picked up a kit to recharge the a.c. next, but have to play with the heater lever on the bottom side. Noticed that it isn't really switching things when you slide it to a.c., heat, vent, etc. Everything just blows out the defroster/floor vents. It was doing the same thing on my 87 (which sold today, finally) so it must be something common.

 

Thanks for the report.