I have a 1993 F150 S/C 302 Auto,stalling,surging driveability problem.

KOEO test gives me a 113.452 and 543.

Cleared the computer and same codes appear.

Only runs bad after it warms up.

Please help !!!!!!!!!!!!!!

 

I think you may have some of those mixed up a little...one of those (452) is a "continous" code that wouldn't come up in a KOEO test. Something about the VSS output. The others are high ACT voltage (113) and a open in the fuel pump monitor circuit (543).

You may want to buy one of those little scanner tools for $40. The book is worth as much or more than the scanner. It goes into how the tests are formatted and how to do all the various diagnostic functions

troublecodes.net has the codes listed, but if you're not too good with what a code means in a particular context, it probably woun't help you accomplish much besides wasting money at AutoZone buying parts you don't need.

 

There is no need to purchase anything more expensive than a paper clip to extract codes from an EEC-IV. Don't waste your money there.

The ACT sensor is mounted on the air intacke tract, usually on the air filter housing. Check to make sure it is not unplugged. I is not likely to cause your symptoms.

The 543 is often the result of a stall. Unless the fuel pump's electrical supply is inoperative, it usually is irrelevent.

The 452 is a memory code and is extracted as part of the KOEO sequence. It si unlikely to be related directly to your symptoms.

A fuel pressure test would be my suggestion.

Steve

 

Yeah, you can use a paperclip alright, but if you don't know what the results mean(because you don't have a manual), you'll be doing stuff like buying parts because the results "say" ACT when they really mean there's a short in the wiring.

The FPM code has absolutely nothing to do with fuel pressure...

Unless you're going to sit here and explain the entire test format and the context for various results (I'm not), then he ought to buy the tester, throw out the beeper (if only because some guy on the internet says he doesn't need it...) and READ the book that comes with it.

The book is pretty much worth the price. With that and the tester, you can do all kinds of tests...than actually know what the answers mean.

Or...you can keep listening to on the Internet.

 

I have a code tester and book, it's been sitting in the drawer for years because it's a PITA to use. The book is about as useful as any of the code lists on the internet. If I need to evaluate a code, I rely on the PCED, the EVTM, and my own background in electronic control systems.

I didn't imply that the FPM code had anything to do with the posted codes. In fact, I believe that NONE of them have anything to do with the original poster's driveability symptoms.

I suggested the pressure test because his symptoms indicate fuel supply as a point to be examined.

Since it happens only after warmup, it may be due to a failing fuel pump. The pressure test willl either confirm that or will clear the FP of suspicion and indiacte that the problem is elsewhere.


Steve

 

A bad VSS can make a vehicle surge. A bad ACT (or wiring) can also affect driveability.

The problem is that you can't relate all the necessary subtleties involved in diagnosing this stuff. The guy looks like he has three recurring hard faults...and a driveabilty problem. Hmmmm...I wonder if there might be an electronic problem.

The sad thing is that it's become heretical to tell someone to "read the directions". Everyone wants the quick and easy answer.

The "reader" ("counter", really) is easier to use than the paperclip mode and it comes with a pretty useful book.

If you can't figure it out or think it's too hard to use, let's just say that I've never had a problem using one...and the book was very helpful to me back when I first started learning EEC-IV back in the 80's.