As the title reads, my 1984 Ford F-150 is not starting. Really appreciate any input from more knowledgeable and experienced hands.


It cranks but has no spark. Truck was vibrating pretty bad before it stopped starting. I have replaced the following already.


In this order.
-Battery and Alternator (Prior to the issue with no spark, but worth mentioning)

-Spark Plugs

-Ignition Coil

-Distributor Cap and Rotor

-Spark Plug Wires

-Solenoid


Honestly, I don't really know where to go from here.

Here is the longer version of the whole situation. The battery was old and the alternator went out so I replaced those at the same time I did an oil change. The truck was running again.


Then I pulled into my driveway one evening a week or so later and shut off the truck and when I went to start it again the next time it wouldn't start. I then realized I made a stupid mistake, I filled the oil about half a liter too much and I drove maybe 8-10 miles over the course of a few days with the oil overfilled. I also had noted that the truck was vibrating pretty noticeably on the last drive before it quit.


Ok, so I drained the extra oil and looked at the spark plugs, fouled. So I replaced them all as they were old anyway. Still no spark. So I got the multimeter and 12v tester light out and started checking things. The battery sits at 12.9v. I have a trickle charger keeping it topped up while I work on the truck.


I opened up the carb and checked that fuel was present when pressing the gas pedal, so fuel shouldn't be the issue as far as I understand.


I checked the ignition coil with the multi-meter and it was showing above the normal specs, which I read means it was an open circuit or something like that? Anyways I replaced that, still no spark.


Then I replaced the distributor cap, rotor, and spark plug wires. Still no spark.


With the test light, I get power to the ignition coil post and through the spark cable that connects to the distributor. When I check for power on one of the spark plug posts on the distributor, while someone cranks the car, with the test light there is nothing.


Pulled all the fuses from the fuse box under the steering wheel, none appeared to be blown.


Checked a few relays with a test light and all the ones I could check are getting power. I am pretty confused looking at a wiring diagram so I honestly don't know what relays I checked I just checked all the ones I could see.


Got some advice that it might be the solenoid. Replaced that and still no spark.


Pretty tired of guessing what part it might be and throwing money at it. My only ideas at this point are...

- Bad Starter Relay?

- EEC-IV ?

- The internals of the distributor? (Condensor, Shaft, Drive gear)

- Did something wrong in the installation of one or more of the parts?




Grateful for any input and ideas!

 

I don't think such a minor overfilling would make any difference.

Have you reinspected the new plugs? If that extra oil somehow caused some damage which fouled the old plugs, that same damage should also foul the new plugs. Once again, I highly doubt the slight overfill caused any trouble, but look at the plugs for peace of mine.

I'm no fan of trickle chargers, but it's better than nothing. Even though the engine doesn't start, does the starter cranking speed seem normal or is it sluggish?

Regardless of the cranking speed, I'd suggest reading battery voltage while the starter is engaged. You may need a helper to turn the key while you watch the meter. It's entirely possible the cranking speed seems okay, but the voltage available to the ignition system is too low for a reliable spark.



​​​​​​​Oh, that's a good one. Did you hear the one about the guy who walked up to the bartender and said, "Surprise me"? If you're going to tell jokes, so am I. Since you mentioned no spark, put a possible fuel problem on the back burner. Who knows, but maybe there's a problem with your method of testing for a spark and the ignition system is fine and there really is a fuel problem. Not trying to bust your butt, only want to be careful we don't go down the wrong rabbit trail.

​​​​​​​More details on these measurements, please. What were the specs and what did your meter show? And did you test the new coil? It's entirely possible to get new parts bad from stock, which can be a troubleshooting nightmare.

​​​​​​​What kind of tester are you using for this step? A tester specifically designed for checking spark? Or are you somehow taking a reading with a multimeter? I think the former, but want to be sure.

And please define "get power to the ignition coil post". Are you talking about the center post where the fat cable is connected? Or one of the small terminals?

This is easy enough to check. Remove the distributor cap and momentarily engage the starter. Does the rotor turn?
​​​​​​​

Always a possibility, or even defective parts. You'll have to systematically work through troubleshooting, being careful to consider you may have inadvertently introduced a new problem during the parts catapult phase of troubleshooting.

​​​​​​​
​​​​​​​

 

Filling the oil too high causes no harm but a little power lost due to a crank will slow down due to too much oil. That fact is not really worth mentioning. It’s not harmful, if you correct the level. Very high oil level could cause a very slight vibration. But, it wouldn’t harm an engine running it for a short period.
Use a spark tester, not a multimeter. They only cost a few bucks. Determine which part isn’t transferring spark. Test coil, distributor and plug wires to verify where the problem is. Today, just because parts are new. Doesn’t mean a damn. Parts today, can be junk straight off the shelf. So, don’t rule out anything new. You don’t need to keep buying parts, Test each one and parts are usually returnable.
​​​​​​. Sounds like a coil to me, verify the coil is producing spark at the coil. Your ignition box could need replaced too. Sometimes, the little power or ground wires come loose from the coil causing no spark. Coil failure is very common. Grab a used one and swap them out to find out.
If plug wires are getting spark. It’s a fuel delivery / carb problem. You mentioned plug readings. Plug readings determine the state of your carburetor monitoring fuel and air. A plug reading also determines health of particular engine cylinders.

 

I agree, you are guessing you have no spark, I haven't seen you properly test for spark. LIke was mentioned, the testlight will test for 12v, not for 12,000 volts. You can go buy a spark tester, or you can take the coil wire completely off the distributor cap but leave it on the coil. Stick a screwdriver up in the end of the coil wire and hold the screwdriver by the plastic handle and put the metal part of the screwdriver very close to something metal on the engine, but leave a small gap. While you are holding it there, get someone to crank it over. You should see sparks jumping from the screwdriver shank to the metal part of the engine if you have spark.

What engine is this? A 300 six? You mentioned a TFI module?

 

I pulled two of the new spark plugs and they look completely new still. No residue or carbon or anything. I did drain the extra oil already.

Ok, so I cranked it for a good 10 seconds with the multimeter on the car battery. It was 12.6 resting and held at 10.4-10.5 while cranking.

It sounds strong when first cranking it. Of course, after cranking for a minute or two the battery gets drained, then it sounds sluggish and I put it back on the trickle charger.

I read online that a coil should read between 6-10k ohms. Out of all the parts I've pulled the old coil is the only one I am not finding so I don't remember exactly the numbers but I remember it was above 10k ohms. The new coil sits at 7.75-7.8k ohms with the battery disconnected and 7.95k ohms with the battery connected.

​​​​​​​I checked with both a spark tester just like the one linked below as well as the 12v tester light. So plugged the spark tester into the center post on the coil that runs to the center post on the distributor. No spark on the tester. I also confirmed that the spark tester was working on my other vehicle. Then I put the ignition to 'On' and checked that the coil and spark plug wire connected to the main post both were at least getting power. Hopefully that makes sense.

[url=http:// [ame]https://www.amazon.com/Lisle-20610-Inline-Spark-Tester/dp/B0002STSC6/ref=asc_df_B0002STSC6/?tag=hyprod-20&linkCode=df0&hvadid=312280085431&hvpos=&hvnetw= g&hvrand=15090296945884005846&hvpone=&hvptwo=&hvqm t=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9033464&hv targid=pla-406644544735&th=1[/ame]) ]amazon link example of spark tester

Yes, correct the center post with the spark plug cable.

Did that and yes the rotor turns. Check that off the list.

Just to make sure I am understanding you correctly. To measure the coil for spark you put a spark tester on the main terminal of the coil with the cable that runs to the main terminal on the distributor, correct? If so I have done that and can confirm no spark from the coil. But I already replaced the coil and the secondary resistance reading is within range. 7.75-7.95k ohms.

Sorry, are you referring to the ignition control module or something else?

[/QUOTE]

Sorry I must have forgotten to put that I did use a spark tester to check for spark. I didn't do the screwdriver test method though.

Its a 351 windsor v8. With t-18 4 speed transmission if that matters. Not 100% on the TFI module. It does have a EEC-IV possibly one of the first models to have that.
​​​​​​​

 

If you have EECIV, then you do have a TFI module. It's the rectangle piece mounted on the side of the distributor. It is what generates the signal to the coil for spark. They are known to go bad from heat.

 

I see your truck is a 1984 model. Probably no relation, but I owned an '84 Ford Tempo back in the day that went through TFI modules about every 6 to 8 months.

It would start off quitting at stoplights. If you didn't soon change it out, it would start quitting while driving. I never let it get bad enough to leave me sitting.

I kept an extra in the glove box, and a ground down nut driver to change it with. It takes a very thin wall socket to fit thr bolts holding the TFI on. I just took a grinder to a nut driver and made my own.

 

Good, so the new plugs are not getting fouled.

10.4v with the starter engaged is good.

Careful not to burn up your poor starter or starter relay. If the engine doesn't fire up within several seconds of cranking, don't keep going and going and going, in hopes that the engine will somehow magically start despite all evidence to the contrary. Sounds like you're on the right track to figure out why, but don't compound any existing faults by adding a burned out starter, etc.

Sounds like your old coil was out of limits, but the new one didn't fix the problem. Even though the old one was bad, it may have still been working somewhat and wasn't the root cause of the no-spark condition. In other words, you found A problem but not THE problem.

Good find. You've narrowed down the fault to no spark leaving the coil. You can forget about the cap, rotor, and plug wires for now.

Excellent. Good troubleshooting. You've ruled out a problem with the tester.

You totally lost me here. Once again, please define "getting power". Are you measuring battery voltage with a voltmeter? Or looking for the presence of a spark with the spark tester?

Yes, that is correct. Sounds like you are testing correctly.

The new coil itself is likely fine. Did you test the primary side? I don't have the specs, but am thinking it's a few ohms at most.

If the primary and secondary circuits within the coil test okay, most likely the coil is not getting the signal to fire. As the others have already mentioned, if this is a TFI distributor (rectangular module sticking out), that module is highly prone to failure. Normally I don't like to shotgun parts, but the TFI module has such a high failure rate, I'm willing to gamble your hard-earned money. And if it the module hasn't failed now, it will at some point, so you'll thank me later for having a spare. A simple public thank you would be sufficient, unless you wanted to hire a skywriter or do a Superbowl commercial, or something like that.

Here's what a TFI distributor looks like, with an image shamelessly stolen from eBay:

 

How do I go about testing/troubleshooting the TFI module to see if that's the culprit?

 

I just checked with a 12v test light. It lights up when key is 'On' position. Both the main post on the coil and the spark plug wire that runs to the distributor were getting some level of electrical power. I see now that this isn't the proper way of testing as you have already pointed out.

Here is your public thank you! THANK YOU! I also liked all your posts on this thread (: Your help is very much appreciated.

Ok, I will go ahead and order a TFI module. Just to be clear and make sure I am on the same page, I am looking for something like this? Which is also called an Ignition Control Module?

https://www.oreillyauto.com/detail/c...rd-f-150?pos=3

 

I can't get your link to work. I went to Oreilly's and plugged in your truck, f150 351w 2bbl carb and it came up with the duraspark module and the TFI module. Here is the TFI module. Let's see if my link works.

Make sure you use lots of the special grease that comes with the module. That helps conduct the heat from the module into the dist base.

https://www.oreillyauto.com/detail/c...n+module&pos=5

 

Forgot to make an update. The TFI module was the culperate. Replaced that and the truck is running now. Thank you everyone for your helpful advice!

For anyone reading this in the future. Having the specialized tool to remove the bolts that hold the TFI module in is a good idea. I didn't realize and had to order it after the module arrived.

Cheers.

 

If the module is held on by small nuts recessed into the module, then you can take a nut driver and use a grinder to make the wall of the socket thinner.

I made one like that I used to carry around when I owned a TFI eating Tempo.

Glad you found your problem.