The truck is an '88 f 250 351 (fuel injected), after failing my state emissions test I poped the hood, found a few problems visually, ran fine after that. To make sure it would pass next time I went to get the codes from the computer. Did a KOEO test, just code 11, so no codes. There were two memory codes though, 34 and 63. Both are listed as intermitent problems, but I decided to check the EVP and EVR. They checked out ok.
Got back in the truck to start a few minutes later and it wouldn't start.
Shot some starting fluid in the intake and no fire, so I'm pretty sure I lost the spark. It's got 12v going to the coil when the key is on and the coil has continuity through the low voltage side. I read how to test the coil and TPS from one of fefarms' postings(big thanks to you). I'll be doing that tomorrow.
While digging around the coil I found two wires near the coil just hanging there. One goes in to the harness and is the same color as the +12v going into the coil, this bare wire also has 12v. The other bare hanging wire goes to a capacitor/condenser mounted next to the coil. Where do these things go? The coil has 1 pos wire in and 2 neg running to it.
Also, what is the PCM? And whats the SPOUT connector?
Anything else I should look at?

This site is great, thanks guys for getting my truck running again.
Rob

 

The capacitor mounted on the coil is for radio noise suppression. There is supposed to be a wire running from this capacitor over to the positive side of the coil. From the sounds of it, this wire has broken in half, leaving you with two dangling ends. Just make sure that the end on the harness side can't short to anything. You don't need to fix/reconnect the capacitor.

The PCM is the Powertrain Control Module. AKA Engine Control Module. AKA EEC-IV,
AKA computer.

The SPOUT jumper is in the wiring harness near the gray 6 pin TFI connector on the side of the distributor.

Get yourself a cheap test light, put it on the negative side of the coil, crank the engine. If the test light flashes, the TFI and pickup are probably OK. If it doesn't flash, there are problems with the primary ignition circuit.

 

I taped off the tan wire going into the harness and will leave it alone. I'll also try the test light test next thanks. As for the test I read about, let me know if I did it right. I plugged in an extra spark plug and wire to the coil, I put 12v to the low voltage side of the coil using a jumper from the plastic connector, ran another jumper from the negitive side of the coil. I heald the spark plug and negitive wire to ground for a few seconds and when I pulled the ground wire off I got no spark across the spark plug gap. Of cource there were little sparks when I connected the ground wire to the body ground(I used the master cylnder as ground), but nothing off the spark plug. The coil should charge the high voltage end almost instantly right?
Thanks again, Rob

 

It isn't a real great idea to try to force 12 volts on either side of the coil. It is safer to let the vehicle supply power to one side, and for you to ground the other side.

Here's how I would do it. Pull the coil high tension wire out of the distributor cap. Connect it to your old spark plug. Figure out how to ground the shell of the spark plug.

Turn the key on and verify that there is power to the plus side of the coil primary.

Connect a piece of ordinary 12 volt wire to a good ground. Momentarily scratch the other end on the negative side of the coil primary. You should be able to generate sparks from the test spark plug as you do this.

This will test the ignition coil, and the supply of 12 volts to the coil, and that's about it. The ignition coils rarely fail.

 

That's what I did, still no spark from the plug. I think I'll borrow or buy another coil.
Thanks, Rob

 

I have owned a number of Fords of this vintage and have had my share of ignition problems with them so I consider myself a bit of an expert on the subject. Usually the ignition module, the thing that is held on the side of the distributor wih 2 hex head screws and takes a special tool to remove, is the first thing to go dead. I did have one coil go bad on a 1987 taurus, but it was intermittent, the car would guit at times when warmed up but then restart after cooling off. I also had one stator go bad on a 1988 F-150 with a 4.9l 6 cylinder, it was intermittent for a long time in that it too would quit and then start later, it finally died completely. Bottom line if you have current up to the coil but no spark at the plugs, I see three possibilities(barring a bad or corroded connection, which I have never experienced) the coil, the stator, or the ignition module. My first guess would be the ignition module. Good luck.

 

This thing was running great, parked it for 5 minutes, checked the EVR for resistance, went to start it and nothing. I've been thinking about the coil because it's near where I was messing around. What should the resistance of the low voltage side of the coil be? Is there any way to test the high voltage side with a multimeter?
Rob

 

I don't have the exact specs handy. The coil primary should be somewhere between 0.5 and 5 ohms. The coil secondary should be around 5K ohms.

A cheap test light is the easy way. Ground one side. Slap the other on the negative side of the coil primary. Crank the engine. If the test light flashes but there is no spark, the coil is bad. If the test light does not flash, but is always lit, the TFI or pickup is bad. If the test light is dark, probe the positive side of the coil primary. If the positive side is also dark, the power feed to the coil is bad. If the positive side is lit, but the negative side is always dark, the TFI or wiring is bad.

 

I'm having this same problem with my '88 F150 (again) The first time it turned out to be a wire going to the fuel pump relay had broken... If you can hear your fuel pump energize when you turn the key this probably isn't the answer, but it will keep the truck from getting a spark