1993 F-350 7.5/460 automatic 120,000 miles

This succubus bitch of a truck will never let me go. New problems keep popping up. It is a battle to get the key out of the ignition. A light went out in the instrument cluster. The oil pressure gauge stays low until I bump the dash with my palm then it goes up more with each bump. The hood release doesn't spring back. The 900 CCA battery tested 336 CCA failing their test. So another battery is needed.

Now for the biggie: It had a very small rough idle before, hardly perceptible. I was driving around shopping and before the third shut down of the trip when I turned off the AC a noticeable increase of engine speed occurred. The tachometer showed 400-500 RPM. It is usually 800-900. I don't know what is normal. Upon restarting the idle was low and there was a hissing noise as if a spark plug had broken and was pushing out air but slower than if that is what it was. It revs up nicely. Sometimes the idle will go up to 800-900 but is still rough. There was a pop twice when lifting off the throttle above 50 MPH. The check engine light did not come on. It did come on for a few minutes last week when on the freeway and I pressed hard enough to down shift.

I am going to find a link to learn how to do the KOER and KOEO tests.

 

Do yourself a favor, invest in a code reader such as the Equus/Innova 3145. It's a handy tool.

If you want to get a jump on running the KOEO tests and CM (stored code) display do this: How to run a Self Test

Do not bother with the KOER tests until the KOEO tests run with a System Pass and the stored codes do the same. System Pass equals Code 111.

 

Good advice. I Ordered a cartridge for a my Actron CP9110 from eBay an hour ago.

Thanks for the link.

The way it is running now I don't want to let run too long.

 

I am not getting this counting the flashes thing. I made a video so I could watch it over and over. I am feeling pretty dense. I put the video on YouTube. Could somebody look at the video and tell me what you get? Thanks.

 

Nobody can help? Guess I have to wait for the scan tool cartridge.

 

Clipped this last night:

 

Thanks, but somebody already sent me the link for this. I understand the procedure but I can't recognize the pattern to get the code. I must be slow. While watching The Simpsons, I have to pause to read what Bart is writing on the board during the opening sequence.

 

codes 111,542

 

Thank you.

 

That's a fuel pump circuit code, and is really common if you switch tanks while running. A very common source for low/high idle issues is a stuck/dirty IAC valve. Sometimes taking the valve off, cleaning it, and then lubricating it with something can bring it back to life.

 

I'll check the IAC.

I was so pleased when the scan cartridge arrived in the mail Saturday. I scanned for codes and it said that none were stored in memory. Went to the section where it monitors parameters and was surprised that it had only about half as many as the GM cartridge. While driving it showed open loop and O2 sensor of .05 volts. ( I would have expected that the CEL would be on for this) Great that is the problem. Bought a new sensor, got back in the truck and it was showing the parameters instead of "lost communication" or something to that effect. I started the truck and realized that the display was frozen. I cleaned with "Deox-it" and checked for tightness all the contacts on both connectors. It still did not work.

Thinking that there might be a bad solder joint I opened it up and all looked good except the PROM was in the GM socket instead of the Ford as marked on the circuit board. Whether this was intended or a defect, I don't know.

It did go through the KOEO and KOEO tests and reported MAP and O2 sensor problems and that there was an unstable idle.

I used the scan tool on a friends 1994 Lincoln and it did not work there either.

I really want to see what a scan tool says about component voltages before I start throwing parts at it.

Remember how I started this post? It keeps on going. Will this bitch ever let me go?

Ciao

 

I unplugged all the connectors to the engine except the fuel injectors and the one in the intake manifold under the intake runners (what is this sensor?). All were nice and clean. I drove it once since and the bad idle did not return. Hopefully reseating the connectors did the trick.

 

The live data on these older computers was very primitive and slow. The best thing to use for "live" diagnostics is a break=out box.

 

Primitive and slow I can work with. A locked screen I can't. This scanner works nicely on my 1993 Pontiac. Where can I find info on this break out box?

 

Something like this: Ford Rotunda Breakout Box T83L-50-EEC-IV 60 Pin | eBay

It breaks out all the computer's pins so you can test everything you want in-circuit. A couple of different manufacturers made them, and you can usually find one for a better price if you wait a bit and check every few days.