Bought a 94 F150 from an auction that's got no spark and hoping someone can give me some trouble shooting step by step tips. I just got it and havent bought the Haynes manual yet but hoping to try a few things first with any advice you can give.


What I did first was starter fluid in the throttle body and nothing, checked the shut off relay its good, pulled the center coil wire from the distributor and cranked it and nothing, no sign of life.

At that point I had to leave. I didn't have my electrical tester with me so my plan for my next visit will be checking to see if there's power to the distributor. I didnt have time to pull off the connector so.....

hoping for any advice for possible things to check next for both scenarios, it has power it doesnt have power.....

For the case of no power.......can I simply run a hot wire off the battery to the connector so I can at least start it and limp it home? of will I do some damage elsewhere be doing this? What else can I check if no power to the distributor?

As for the case if it has power, I'll pull the distributor cap and see if anything looks bad.

Thanks for any advice you can provide, Im a novice mechanic so take er slow for me! I'll be back to the car on Thursday or Friday so can report back on the voltage then. Any tips please pass it on! thanks!

LATEST UPDATE SUNDAY 9/2....

First want to thank you both for your replies and details and pics was a great help but.......

Finally got back to the truck today and got my check for a hot wire tester out and the red wire to the coil was hot when the key was on and when cranking it.

I removed the coil to distributor wire and held it close to the lead and cranked with no visible spark out of the coil to the wire.......at this point Im thinking it just has to be the coil.....so ran to the auto store and happily spent 20 bucks on a new coil....gotta be the problem.....slapped it in cranked and same thing no spark ....

Then I was thinking mabey low voltage at the coil, my voltmeter was dead so I looked at the subford diagram and this truck was a bit different and not labeled well. I took a pic if I need to go jumping it but she does have power.... This thing has an inline six banger in it.

At that point I tried a hot wire from the battery to coil and cranked, still no spark......

At that point I'm stumped so i left and picked up a spark tester on the way home so Im not guessing if theres a weak spark or not.

Im hoping to head back tomorrow or tuesday so again any advice would be great.

Does the voltage to the coil drop down or is it 12V? I also had power doing to one pin of the distributor connector and well. Assume thats normal. I will get the exact voltage read next visit.

So thats where I stand.

Any help on what else I might try let me know!

Thanks Chris

PS....I also removed the SPOUT connector and cranked with no spark, I never unplugged the computer...this was retired from a local college and they usually disclose if it was towed into the facility or not and this one didnt say towed in so thinking it ran at one point. thanks again for any help! Should I try disconnecting the computer?

Tuesday Update.... I put it on my trailer and got her home so I'll have some more time to look into things this week.

Yes the fuse panel is the same, thanks for the picture details! Will let you know how its coming later this week thanks again Chris

 

I'd start by checking power to the coil, then test the coil. Go from there if find everything is good up to that point.

If no key on power to the coil yes to get it home/drive it you can run a hot wire from the battery over to the coil. Connect it the start it up, remove the wire when no longer wish it to run.

Doesn't have "points" like they did in the old days so hot wiring it won't hurt a thing, same thing as leaving the key on.

Oh if you hot wire it you could go as far as use an inline fuse in the wire make it "safer", if you're OCD or something that is. I wouldn't I'd just use a heavy enough section of wire but maybe that's just me!

 

If no power to the coil the best way to hot wire it is to pull fuses "Q" & "U" and use an inline fuse holder with a spade connector crimped on each end and jump it in the fuse relay box. Use a 20 amp fuse in the inline holder and jump pin #35 to pin #44 only in the box.
Diagram below.
But before replacing any parts pull the SPOUT shorting bar jumper out and see if spark returns. If not unplug the PCM Computer and check for spark again.
If spark returns in one of the two above test then you either have a bad computer or the computer has lost its grounds or power to it.

I am sure they have already checked for power and did what they could to it before they got rid of it.
So more than likely it is either the computer being bad or the grounds are bad at the body ground stud by the battery.
Also check the ICM and make sure it is black in color and not gray after you get it running.



SPOUT location:


PCM Computer location:


Black ICM:


/

 

Hello, I replied to you in my post, any advice would be great!

 

You can try disconnecting the Computer. If the spark returns at that point you need to check for power and grounds to the computer plug.

But more than likely you have a bad PIP sensor in the distributor not sending a PIP train to the ICM.
You can replace the stator in the distributor (the PIP sensor in mounted on the stator).
But the distributor has to be taken out and taken all apart to replace it so most just replace the distributor.
You can use an LED to check for a PIP train but it will not start while the LED is hooked up. But you can see the LED flash while the engine is cranked. If no flash then you have no PIP.

 

By the way what is different in my photos and diagram?
The should be the as a 1994 and it does not make any difference what engine is in it.

Here is another view on the fuse/relay box that is in the diagram above.


The LED talked about above:


/

 

Well I pulled the SPOUT connector and no spark. Went to pull the PCM, looking at the picture u sent with the green outline, I thought I could loosen the bolt and the connector would slide right out, I removed the outer plastic cover easily but didnt see an easy disconnect anywhere, do I need to give it a good yank and shell come loose? or do I need to go inside the car and disconnect what I read on another site....


Inside the vehicle, pry the scuff plate off the bottom of the passenger's side door with a slotted screwdriver. Remove the kick plate from the passenger's foot well in the same way.

4


Remove the retaining bolts on the top and bottom of the PCM with a socket wrench. Carefully slide the PCM out from under the dashboard.
so....your picture ....below the green outlined one shows a PCM connection....I didnt notice a connection like that but it was dark out with just a flashlight so.....if you can let me know if the firewall connection is what I need to disconnect or whats in your picture, mabey you can expand on where it might be.

I need to pick up an LED assembly and I'll try the rest of the testing...

I will have access to a u pull it junk yard with loads of fords this weekend with real cheap parts, sounds like yanking a distributor might be a good idea? should I yank the computer as well? thanks again for your help. chris

 

You did not have to remove the plug shell. Just back the 10mm bolt out and wiggle the plug each time the blot gets hard to turn and it will unplug.
No there is nothing inside to do. It is all under the hood.
There is nothing behind the passenger side kick panel except the fuel shut-off switch.
The computer is not under the dashboard. It is behind the drivers kick panel an is excess from under the hood.
See above replies.
Yes and yes but most of the time they have already been striped out before you get there.

 

Cant thanks you enough for your support on this!

After tinkering today and doing some of your tests, I all of the sudden have a spark!!!! Not sure what fixed it but it lit up the tester so...

I shot some starter fluid into the throttle body and she ran for a second, then sprayed some fuel into the body and she ran for a few seconds more as I sprayed fuel.

So the good news I have a spark, the bad news looks like no gas flow but I haven't done my homework yet so tomorrow I was going to put my ear by the tank and see if I can hear the fuel pump come on. And more importantly I'll check the tank and make sure theres gas in it!

I did check the inertia switch and its popped up like it should. Any tips on what to check next if the pump comes on? Could a clogged filter or injector be easily checked?

One thing I noticed was the fuel gauge is stuck on about 3/4 of a tank and doesnt budge when I turn the key on or off. Could this be causing no power to the pump?

If I get no noise at the pump I was going to switch the fuel pump fuse with the horn fuse and see if it comes on, .....if its still dead should I be dropping the tank and testing for power to the fuel sending unit?

Once again cant thank you enough for your help! Fingers are crossed that she sparks tomorrow! regards,

Chris

 

I did check the inertia switch and its popped up like it should.

Umm you wanna push that down if it is popped up, you need to reset it so the pump/s will run.

 

Just ran out to the car pushed it down and runs perfect!

I owe you guys both a cold one if you're ever in North Florida!

Wife is very happy she doesn't have to keep running out there to crank it for me!

I also bought an F350 with problems so more questions to come!

Thanks again guys, with a big smile on my face and a load off my mind!