1995 with 5.0, runs great when engine is cold. Once engine warms up you don't know if you will make it around the block, then it will just start running just fine. When it runs bad there is no power and backfires thru the air cleaner. Seams like the timming gets very retarted when it runs bad.

 

Is there any codes? might what to scan for them & see what is present.

What have you done to remedy this? so we are not covering old ground

it can be several things

 

This is my brothers truck. It did show an O2 code, cleared that, The shop also thought there was a problem with the distributor and the timming was changing. They thought the timming chain was "OK". Monday we replaced the distributor, rotor, cap & PCV. The spark plugs and wires have 20,000 miles on them. I did pull a couple of plugs, they looked "OK" Checked for vacuum leakes, none were found.

 

Could be the ignition control module acting up.

 

Am I correct, in this year the ignition control module is in the bottom of the distributor and we did replace the complete distributor.
We were just driving the truck and it started running bad again, The check-engine light did come on but there were no engine codes, this uses the OBD1 system, I understand this is not very reliable. We did replace the ignition coil at this time. Ran good for about 20 minutes, then the same old running bad.

 

No, not correct. On a 1995, the ignition module is above the fenderwell on the driver side. Next to the fender, I think bolted to the fender.

 

Thanks, we'll check it out. Happy New Year, Dale

 

I had a 5.0 Mustang that did exactly like you're describing, and it didn't throw any codes either. It ended up being the IAC module. Maybe that's it?

One thing I wish was different about Ford. If something is bad or going bad, I wish it would go ahead and throw a code instead of waiting until it runs so badly you're afraid to drive it.

 

1. Check the O2 sensor first, it probably needs to be replaced. You got an O2 sensor code so you should have started there. Use a Bosch brand O2 sensor. Ford used them from the factory.
2. Pull and clean the IAC valve with carb cleaner.
3. Check the ECT sensor. Speed density is a combintaion of sensor readings. The ECT will tell the computer when the engine is at running temp. I would just replace the ECT as they are less than $20 at most part stores.
4. Ensure you use a thin film of Dielectric Grease on the IM. And yes, they are on the drivers side, just forward and below the hood hinge. Get one with a Lifetime Warranty if possible.

 

Not a good idea - use WD-40 or Deep Creep, work the plunger with a screwdriver till it's free.

 

I actually used TB cleaner on my Gen. 1 L IACV. Most people use electrical, TB or Carb Cleaner on the IACV. It may have alot of crud coked up on the plunger. You will need something strong enough to remove the build-up. I guess Deep Creep would work.

 

Have a ingition module coming today, we'll also pick up a ECT valve and clean the IAV valve. Keep you posted. Thanks for all the help, Dale

We replaced the ignition module and it's been running good for 4 days now. We also wanted to one thing at a time, so were doing the ECT valve & the IAV valve another day. Dale G.