Recently, my 94 E250 4.9L began missing--badly. Thought it might be just one or two cylinders. Yesterday I pulled the "coil" wire from the distributor side, inserted a screwdriver into the boot of the wire, layed it down near the coil wire terminal and then ran the motor. Determined that the spark misses in varying intervals of around 10-30 seconds. Obviously, these misses aren't enough to stop the engine from running, but it's getting worse, not mention annoying.

Where should I begin? Is it possible that the coil wire is bad?

For what It's worth, I replaced the plugs, wires, cap and rotor about 7,000 mi. ago.

Thanks

 

Even though you replaced the wires cap and rotor 7,000 miles ago, you need to reinspect everything. Is the rotor button or distributor cap pitted? Any visible damage to wires?

You can improve your ignition test by using a spark plug instead of a screwdriver, since there is no way you hold the screwdriver at .045" . Hold the tip of the plug firmly against the block. You may see a big difference in your test.

My experience is that the rotor button is what goes first and causes the most problems. If there is corrosion on the end of the rotor scrape it off and give it another try.

 

Hi,

Yes I cleaned ALL signs of carbon tracking from the cap and rotor. Inspected the cap, button and plug wires. No problem. I did all this prior to conducting the highly advanced screwdriver test. I don't have any spare plugs. I don't keep extra plugs around anymore like I once did, but I'm confident that the screwdriver worked well enough to indicate that there is indeed a spark problem. It purrs just fine, then, like I said, skips a bit then continues. Even when I lay the driver directly ON the terminal, the engine still misses.

I've been told that the module in these type distributors do not intermittently operate. They either work or they don't. Any truth to that?

It seems, and this only my opinion based on observation, that whatever tells the "coil" to fire at the precise moment is failing to do so.
I suppose that COULD involve a number of electrical and or electronic things though?

Would it be wise to buy a scanner and scan for possible codes?

Thanks

 

I do recommend getting a code reader, since you can get a nice one with Digital display at Walmart for about $30.00. I have a 95 E150 300ci (actually running fine) but I bought the OBD-I code reader with digital display, because it was so cheap and easy to use. The blinking light code readers @#$#$. Get the one with Digital display!!!! Covers many years and models of vehicles up to 95-96 they started switching to OBD-II. Warning - You do have to read the code reader instructions in order to use. There are multiple tests that can be run, such as Key on engine off, key on engine running. You don't just plug the code reader in with the engine running.

 

> I've been told that the module in these type distributors do not
> intermittently operate. They either work or they don't. Any truth to that?

If you have the gray rect. mod. that sits on the side of the distributor (TFI) with the four or five wires then yes, they can operate on or off, or not at all. I know that from personal experience from working on many Fords with EEC systems. Though usually when they operate on and off, they throw a slew of random codes.

You did not mention how many miles on your vehicle, but, I assume well over 100k. What I would check is slop in the distributor as that could cause the problems you describe. Plus, if you have a defective hall effect switch (they can test it at Autozone) inside your distributor, then this could cause the problem you describe. Though this is a rare failure and if it does, it is far easier to just replace the distributor with one already installed.

You should check the coil and suspect it even if it tests good. What I would check very carefully is the connection to the coil. In rust belt states the connectors will rust out and from back probing they appear fine, but, if you remove the connector and test from the connector side you will find little or no voltage getting through.

 

Icewagon, Could you perhaps post the precise details (make/Model) of this code reader?
I could get friends to obtain one and send to me, as I am 3000 mls away from the nearest US Walmart.
The Ford dealer charges US$40, just to do the test, and independent shops even more!
My vehicle is an E150 with 302 V8 '93 vintage.
Does the Walmart codereader show on the box wich models/years are covered?
Thanks for the info; if nor answered on the forum, please send me a PM.
Cor

 

You can read the codes by counting the flashes on the check engine light, there is a proceedure to follow. This way worked a lot better than the Walmart special tool, at least for my 89 Crown Vic.

 

Yes I know, GLR, but I am getting confused by the pauses between the flashes, as there are multiple numbers generated, and the problem is to know when to start counting, and when the next number is coming up.
Again, I kow the procedure with the light or the analogue multimeter, but I find this very troublesome.
But thanks for the imput anyway!
Cor

 

I don't have the code reader in front of me, because I am at work. But I do recall that, it is black with a yellow tag on the front that says FORD OBD-I. I will try to find some more info.

 

Yes. That's the one.




It does have have over 100K and I wouldn't be surprised if the dist. is a cause or THE cause.

There are presently 123K miles now on the vehicle. The first 90K miles or so originated in the Palm Springs, CA area (terribly dry environment), so if there are any rusty connectors, it's unlikely they got that way during those years. The van has been in Colorado, along the "front range" of the mountains, now for about a year and it's possible, I guess, some rusting might have begun during last winter or shortly before and after. It's been EXTREMELY dry since about mid May.

Nonetheless, thanks for the tips. I'll look into these things and report back.

 

Ok. I'll set my sights for one of these then.

Yes. I have a Haynes manual that also indicates the various "key on", "key off" procedures.

 

I did a search on the internet and found this: Equus 3145 Ford Code Reader, You can buy it online at Autobarn.net for $36.95.

I paid less than $30.00 at Walmart, but you never know wether it will be in stock or not. As a matter of fact, I was at my local walmart last night and I didn't see any OBD-1 code readers, but they had the OBD-II..

So check out the Equus 3145 on line at Autobarn, I highly recommned this tool. As you can see on line the on screen digital display kicks butt over @#$#$ blinking LED!!.

 

the haynes manual dosen't tell you how to count the flashes? Mine does for the beater car I own, but it is a little hard to get it right for the multiple codes like you spoke of. My car has a definate long pause between codes.

 

Had a similar problem in my 88. Turned out to be the power wire to the computer (not the ignition module). I found it because it eventually failed completely.

Disconnect the single pin connector by the distributor and recheck your spark.
If it still misses, then your problem probably doesn't involve the computer.

good luck
ford2go

 

From my experience of looking for a code reader for my wife's T#y%ta, most of the OBD II readers will work on OBD I, also. Read the fine print for that, and, what it actually tests. Some of them are misleading as to "ease of use".
Munrow