I recently purchased a 1991 F150 5.0liter EFI. It has ran great up until a couple of days ago. I went to start it and it wouldnt stay running, engine sputtered as if the plugs werent firing. First off, I am not much of a car guy but I understand the basics. I thought first that it was possibly something to do with the Distributor Cap/Rotor so I replaced the distributor cap and rotor with a used one I had got when I bought the truck (the guy threw in a bunch of parts). Everything seemed to work fine so I decided to replace the plugs/wires/cap/rotor with brand new ones. Did this and now 9 out of 10 times when the truck is running it sputters and dies at stop lights. It appears to me that it isnt getting a spark and that is causing the engine to cut out.

I havent really tried anything else besides making sure all of my connections are good. Any ideas on how I can test it more thoroughly?

Thanks

 

I'll suggest TFI module just to get things started and then I'm sure the "EXPERTS" will jump in here with more possible suggestions.



guzzler96

 

If the engine sputters, coughs, quits, and won't restart, check to see if you have spark. If there is no spark it is probably the TFI, Hall Effect pickup, or grounds. If there is spark, check the fuel pressure.

If the idle is unsteady and the engine eventually dies, but restarts with a twist of the key, you could suspect vacuum leaks, stuck EGR pintle, fuel regulator, fuel filter, etc.

The exact symptoms aren't clear from your post.

 

It does easily restart after it dies. From a cold start in the morning, when I start it it shoots up to 2000rpm like normal then instead of slowly making its way to idle it drops drastically sputters and most of the time dies. Tonight when I drove from the parts store to school it ran fine. Usually, it sputters on take off as well as while i am cruising at any speed and it sputters/lurches forward while I am stopped at a light.

I bought a "Control Module" ($26 at Autozone). Is this the TFI module? I asked the guys at Autozone as well as O'Riely's about the TFI module and they both gave me a bewildered look and said "do you mean the control module". I am going to try that tomorrow but also would like to put a fuel filter on just to make sure, plus I have no idea when it was last changed....if ever.

Are fuel filters easy to replace, I am pretty handy with tools and feel very comfortable working on the inside of the car (I used to do car stereo/alarm/sunroof installs) but am kind of green when it comes to under the hood stuff.

P.S. Thanks for everyones input, this is by far the most helpful forum I have ever been to.

P.S.S. Is there anyway to find out if any mechanics in my area (Belleville Illinois) use this forum and would want to work on my truck if I cant figure this out on my own.

Thanks,

 

If you scroll down a little further past this forum, there are individual state chapters. You might look around in the Illinois chapter and see if there is anything about mechanics or anything in there. I guess you could always post in the Illinois chapter and see what happens. There is a website too that has a place to put in your state and it returns some mechanics. I'll see if I can find it and post the link.



guzzler96

 

Autozone sells a "Wells F121 control module" for $39.99. This is their nomenclature for Ford's TFI module. This mounts to the side of the distributor and plugs into the pickup coil inside the bowl of the distributor. It is a gray rectangular item about 2 inches by 3 inches by 1/4 inch thick. You need a special socket to get at the attachment screws.
When this goes bad , you usually lose all spark, at least for a while.

I would recommend learning to run the KOEO and KOER tests. See if the computer is trying to tell you anything. The KOER test will exercise the IAC and idle RPM through a range of values, which will recreate to some degree the road symptoms you are seeing. It is a lot more convenient letting the computer do this in your driveway than sitting at a stoplight on the road.

 

It looks like the problem has been fixed. I replaced the fuel filter tonight (messy job) and it appears after driving it for about 20 minutes that everything is running fine. I also replaced the air filter so that may have been it to but I am leaning towards the fuel filter.

As for the air filter, there is some oil in the air filter case (about 1.5 teaspoons) is this something I need to worry about?

Thanks for everyone's input. I dont work on cars/trucks much as I am a computer geek so this site has helped me tremendously. If anyone ever needs a website built or any kind of computer help please dont hesitate to send me an email/IM.

Thanks,
Kyle K
www.truewebdesign.net