So, I am having some issues with starting my pickup. (84 f150 351w) Mainly my issue comes at starting after the truck is warmed up. Basically, the standard "barely cranks the engine over for a second or two and then cranks up pretty much like normal" sort of thing. My battery is over three years old, and here in AZ if you get anything over 2 years you count yourself blessed, so I started there. I felt that either way, in my quest for reliability, a fresh battery was a good choice. That didn't solve the problem. Then I remembered reading about these same issues with a faulty starter solenoid. It was contributed to the solenoid overheating but not yet to total failure. So, I tried that. No Luck. Still having the issues. I am thinking of doing a thorough inspection of the battery cables next, and if still nothing I will pull the starter and inspect/test it.

What am I missing? Any suggestions?

 

I am more of a six cylinder guy, but I believe your engine had Duraspark 2 ignition. There is an ignition module mounted on the driver's side fender liner. If an original Motorcraft unit, it operated with two circuits: one to start and one to run.

The starting circuit had a feature where the ignition timing was retarded while starting to make it easier on the starter motor. If this is not functioning, an engine can drag at start-up, especially if hot.

 

No duraspark...Not yet anyways! I have the tfi in the truck now. Currently ordering parts to do a DSII swap. Was hoping to figure this issue out first though.

 

I have the TFI IV ignition myself. I find it works very well as long as it is maintained, like anything else. I have some troubleshooting stuff here that might help; Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.
There is also some TFI reference material there.

 

So, after further inspection, i found my solenoid was a little loose on the fender well. Drilled new holes and remounted it. Truck started perfectly and I naively thought i had fixed it! WRONG!!!! Still happening. It even does it intermittently at cold start, so i dont believe it is heat related at this point. Does anyone know the resistance per foot spec on battery cables? Really hoping my starter isnt about to puke out on me.

 

I probably wouldn't worry about the resistance values on cables, I'd just pick up a set of 4ga or larger cables from the local auto store since they'll carry more than enough power for the starter no problem.

Have you thought about taking the starter to the auto store and having them test it? If it's getting worn out it can start drawing too much power or turning slow.

 

Thanks Kirby! I will be swapping out cables tomorrow. We'll see what goes from there I guess.

 

Well, round 3. I pulled the starter and battery cables this morning and took them with me to the parts house. Starter tested fine at NAPA but I was unsure of he really checked its draw just saw that it spun. So, theres a first time for everything right? I went to autozone instead, and had them test it. It tested good on their bench machine in all parameters. So, i picked up 3 new battery cables and headed home. After installing them and checking all other connections, I started her up. She roared to life just like she should. Brought the motor up to operating temp, and shut her off. Restart was just as good as the first. I went on to clean up a few other things I had wanted to do, then I went for a test drive. Drove about 6-8 miles,parked the truck, shut her off, waited a minute, and...........
same ol problem.
still there....
so sad.....
banging head against fender......

Bottom line, was that although it seemed less significant, my truck barely cranks over when I try to restart it. After a second or two, the starter spins up to speed, and she roars to life.
I will have to give a few more days before I am convinced that it wont happen cold anymore, but am thinking that it won't.
Anybody have any suggestions for me?
(as I write this, I am wishing I would have used the normal reply button instead of using quick reply! Didn't think I was gonna write this much!)

 

Check the engine to firewall ground, clean the area where the negative cable grounds to the engine, and clean the starter mounting area and the starter itself making sure it's bolted on tight. The starter grounds through the block.

So if you hold the key to Start, it spins slow then normal speed? Or do you left off when it goes slow then try again and it goes normal speed?


I know that even little connection problems can cause big problems. I had a loose connection on the battery side of the solenoid last night and it was so hot that it burned my finger when I touched the cable end at the solenoid. It was also causing charging issues (12.9V at idle instead of 14V). I tightened it all up and problem solved. Now that I think about it, this had to be why I was having issues with starting when I was setting up my MSD box this weekend.

 

All connections are good, clean, and tight. And yes, while keeping, the key in start position it cranks slow for a second or two then spins up to speed and the truck starts. Currently it is only happening when the truck is at operating temps, and keep in mind i am in arizona..... 105 degree ambient temp today!

 

If it is doing that after normal operating temps are reached.

I would think that is too high on time.
Retard your timing just a little and try again.
More than likely, that will fix your problem, given all the other stuff you have done.

No money involved, just a little time and one bolt to loosen..

Hope this helps...Trav...

 

Thanks for the input Trav. The PO did one hell of a hack job on the wiring, so I have to be very careful about moving the distributor. Also, he hacked up the tfi IV, so as we speak I am finalizing my order for my DSII components, and plan on installing them this weekend. Maybe that will help!

 

You could still have a bad starter, but check everything else out first...

The windings in the starter could have a "dead" spot. I have experienced that before, and it's not easy to diagnose. Will start great, and test on the bench great, until it lands on that "dead" spot.

Heat causes more resistance etc...


EDIT due to new information: The TFI-IV also has a start function. If the previous owner did a hack job with it, this may be your problem, if the TFI-IV isn't going into start mode when you crank the engine...

 

Currently, if you touch the distributor "just right" the truck will start! How fun is that?!?!? I wanna slowly pluck the PO's nose hairs out! DSII happening this weekend, and with it fresh wiring. Hopefully that helps.