Hello.

I have been reading the forum for weeks now trying to solve my problem.
This is my first time posting and I sure do appreciate all the posts I have read . I have learned a great deal. Well let me launch into my problem.
I have a 1986 ranger with a 2.9 engine. When I start the truck it runs ok until it warms up a little then when you put your foot on the gas it revs up and down. It sort of pulses . Give it a little more gas and it stops but then it runs a little rough. I wanted to pull the codes and I have a Hayes manual and I don't find it too helpful in this case. I don't know where to find the plug Or should I say connector to check the code. The picture in the book was so small and did not look quite like what I had. There are so many gismos down there I don't know what the heck I'm looking at.
I thought the problem might be a vacuum leak . But If so why would it only act up when it warmed up a little ? I thought it might be the IAC but then I thought would that wait till it warmed up too or would that just start making problems even before it warmed up. I also noticed that I could smell a different sent coming from the exhaust like it was running to rich. I can drive it for a short distance then it starts to miss and skip and buck some.
pretty soon I should get a cowboy hat and ride it if it gets any worse. lol
I had the bright idea to pull the codes as I said but can't find the plug to test it. So could some one please help me ? I am not a mechanic as I'm sure you can tell. But I do like to tinker on my own stuff.
Thanks so much for any help you may give.

 

I was wondering if this may have anything to do with the problem ? I put on a Ignition Module a few weeks ago and the truck started running again but from the time it started running again it had this problem. Could it be that the new Module is flaking out . Or do they just go out all of a sudden ? BOOM ! The reason I put the new one on is the old one just quit all of a sudden and left me stuck of all places in a parts store parking lot while I was getting parts for a friend.
I also lost one of the screws that hold the Module to the distributor. So one screw is holding it in. I was trying to find a replacement but where do you get them. What size and thread are on them. Are they metric? Could it be A loose connection causing this problem ?

 

Welcome to FTE!!!

If you look in the tech info post you will find the procedure for pulling the codes, I don't think you can use the CEL on a 86. I would get the TFI screwed in tight and I believe you need to put some dielectric grease someplace, can someone provide more on this.

 

Can't help on the IM, except to say I agree with Ken that it should be bolted on properly.

As for reading the EEC-IV codes, these links have instructions and also diagrams of the computer test connecters that can give you an idea of what you are looking for.

http://www.smpcorp.com/download/view/Tt4Q98.PDF

http://www.dalidesign.com/hbook/eectest.html

Here's a picture of what most EEC-IV test connectors look like:

 

Thanks Ken and Rockledge,

I did use the grease that came with the new Ignition Module and I wish I had not lost that screw. Do I have to go to the dealer to get that screw ? I went to the hardware store to get one and they asked is it metric and what kind of thread? Any ideas ? As far as the connector The picture was just what I needed. now I know what I am looking for. By the way is there anything plugged into it or is it a plug just hanging there . I found one on the passenger side in the engine compartment and it was red and it looked like that but it was not plugged into anything.
I can't tell you enough how much I appreciate your help .

 

Sorry I can't help with the screw, you will need to use a thread gauge to find out.

They are not plugged into anything, its possible Ford used different colors.

 

I took the truck to a mechanic shop that had one of those electric diagnostic meters. and It gave a code 12 and a code 21 . At one point he had to restart the test because he said there were so many things with bad readings he thought the main onboard computer ( Pcm) was failing. Then he did the test again and it gave those codes and said the engine was having trouble running at a stable idle speed. Now that I didn't need a machine for. lol

He started spraying a cleaner in the throttle body and it was real dirty. He said I bet if you clean all that bad stuff out of there it will take care of most of your problem. so we shall see. I also will clean the IAC to see what happens.

 

I cleaned out the Idle air control . I cleaned it real good. I put it back on . I cleaned the

throttle body thoroughly . I cleaned all around the butterfly valve on the inside and then

went way back in there with the butterfly open and sprayed a lot in there too. I had the

truck off when I did this and just manually opened the butterfly valve with the throttle

linkage . I washed that thing out real good. I held the butterfly valve open to let all the

stuff drain out. It was filthy. After doing all that I put it all together again. And started it up.

no real change. It is driving me mad. It does that rev up and down up and down. but only

at a slower idle speed after It warms for about 2 maybe 3 minutes . you have to put your

foot on the gas just a little and hold it there and then it starts. Then it misses at higher

speeds. Could the temperature sensor do this ? Help !!!

 

Did he make the repairs for the codes, did he run the pinpoint test?

 

I suppose it could be your Engine Coolant Temperature sensor going on the blink. Read Here About the ECT

Have you re-seated the Ignition Module yet with the two bolts? You indicated that the problem only came up after you replaced it, so that's something you ought to do, so that you can at least rule it out as the cause.