I was thinking earlier pull all the plugs and stick a big screwdriver down to hold the throttle open (like a compression test) hit the starter and see if it spins the daylights out of it.. If it does then look to engine...timing etc. If not...back to battery/cables/ground/etc

 

 

Hang in there bud... here's something you can try as far as the ignition switch.....turn the key on and (safely!) try a remote starter switch.

 

I've got a remote starter I've been using to test voltage drop at starting. I've yet to try it in place of actually starting it, which would rule out the whole keyed ignition side.

A mechanic friend of mine suggested I use the record feature on the high end model voltmeters because some minute drops may not show on the plug in gauge I'm using.

Another thing I can't wrap my head around is why the voltage drops from 13 volts to 8-9 volts when cranking. Sometimes it's above 10 volts and cranks fine, other times it drops and slow cranks. And I also see how a mechanical problem can cause a starter to draw more voltage as it tries to turn over the engine.

 

Generally when an ignition switch is wearing out or improperly adjusted you see people going through all types of contortions trying to get it to crank followed by carpal tunnel.

 

If something is binding mechanically that means more load on the starter resulting in a higher the amp draw potentially leading to in a drop in voltage. Battery's have a fixed amount of amperage they can deliver exceed that amount and the voltage will drop off. Some thing is causing the slow crank. It is not a supply issue (battery) nor transmission (providing you don't actually have a bad cable)

Pulling the plugs and cranking is not a bad idea. Set the conditions for when you would get a slow crank, pull the plugs then try it. If you still get a slow crank time look at mechanical issues,

 

I pulled the plugs, stuck throttle open, disabled ignition and it cranked over just fine. Also returned exide battery (didn't seem to do any better) and also the old battery. Bought 850cca interstate, put it in charger, when topped off I installed it.

Put everything back together and cranked and started just fine, just for my reference, I didn't pump the pedal before starting it, and it cranked 4 occasions at 8 second intervals without dropping below 10 volts. Finally got it started and drove it into town. 15 mile trip, parked in parking lot for 10 minutes, came back out and initially showed 12.8 volts.

Tried to start it and voltage dropped to 7.5 volts before starting up. Only happened for a split second, but I knew the problem wasn't fixed. The only Motorcraft part I don't have yet is a starter, so I guess I'll order it today.

Also thought cheap insurance to replace ignition ignition switch as well, because this one is 32 years old and who knows? I'm getting ridiculous throwing parts at it now. At least I'm throwing motorcraft parts at it.

 

 

I crawled under the dash to take a peek at everything, two things I noticed, probably not the problem, but was a problem. The fuse box holder light bulb wire and a speaker wire were being caught by the arm of the clutch safety switch, and pulled in with the clutch, possibly pinching them.I zip tied them out of the way

i went around some more pushing in connectors and such, and went on a spree cranking the truck till start and shutting off, every 10 tries, letting the engine run to recharge. It may a been a silly test, but I wanted to see how low the voltage dropped. Out of 30 or so tries, 11 were had the hesitation before starting. It started just fine with voltage down to 8.9 volts, but I recorded a min voltage of 7.45 and maximum voltage with hesitation at 8.9. All these were after voltage shown on gauge at 12.5.

also tried cranking key over without clutch pressed in,, then depressing clutch to start, didn't seem to make a difference either.

after I let it recharge for 10 minutes,. I did the test again 20 more times, this time letting it crank and start and immediately shut off. Waited till the starter motor to stop, and immediately cranking again. Didn't have a single hiccup out of 20 tries.

 

I crawled under the dash to take a peek at everything, two things I noticed, probably not the problem, but was a problem. The fuse box holder light bulb wire and a speaker wire were being caught by the arm of the clutch safety switch, and pulled in with the clutch, possibly pinching them.I zip tied them out of the way

i went around some more pushing in connectors and such, and went on a spree cranking the truck till start and shutting off, every 10 tries, letting the engine run to recharge. It may a been a silly test, but I wanted to see how low the voltage dropped. Out of 30 or so tries, 11 were had the hesitation before starting. It started just fine with voltage down to 8.9 volts, but I recorded a min voltage of 7.45 and maximum voltage with hesitation at 8.9. All these were after voltage shown on gauge at 12.5.

also tried cranking key over without clutch pressed in,, then depressing clutch to start, didn't seem to make a difference either.

after I let it recharge for 10 minutes,. I did the test again 20 more times, this time letting it crank and start and immediately shut off. Waited till the starter motor to stop, and immediately cranking again. Didn't have a single hiccup out of 20 tries.

 

Hate to break it to ya, but all that test does is confirm you are proficient at removing and reinstalling spark plugs. With the plugs removed, the starter's job is much easier without having to overcome any compression to spin the engine. Please see my earlier comment about the pointlessness of testing the starter at less than normal load. Last time it was at the parts store. This time it's bolted to your engine sans compression. It's the same basic thing. The ability to walk around a park on a Sunday afternoon is not a good way to determine who is capable of climbing Mt. Everest.


Big clue here. Correct me if I'm wrong, but I think when the battery has been connected to the charger, the next start is perfect, right?

So that had us all thinking the slow crank fault was related to a charging issue, or a defective battery that can't hold a charge. I think we can safely rule out the battery, with this the third one? For charging, are you seeing approximately 13.5 when driving?

So if the battery itself is hopefully good (third time's a charm), and the charging system is holding around 13.5, what variable keeps changing?

My TheoryDuJour™: Radiant heat from those blasted headers affecting a marginal starter. When sitting at home, connected to the charger (talking about the truck, not you), the engine is obviously not running. That means no radiant heat from the blasted headers.

Drive into town, and now the blasted headers start cooking everything under the hood, just like they are designed to do. No wait, that's not by design, it just happens. That's why I keep referring to them as blasted headers. I've seen more problems causes by blasted headers, far outweighing any minor performance increase you might gain.

So let's say that poor starter was already marginal, and then some heat finishes it off. This was the original starter before you did the hi-torque swap, right? I'm assuming (Danger! Danger!) it was already old and tired at the time. High underhood heat from the blasted headers then causes the poor starter to heat up. Note the problem seems more common after sitting for about 10 minutes, which is due to the lack of airflow from forward motion and the radiator fan.

Thermal expansion can cause a marginal short (typically between windings) to become more solid, and next thing you know, the starter draws way more current than designed while delivering less torque. The outcome is the voltage from the (perfectly good) battery drops far too low under load, and at the same time, the starter can't spin the engine at normal starting speed.

How's that for a plan?

Consider a heat shield for the new starter, to protect it from the blasted headers. I'm not a big fan of the blanket type that wrap around the starter. Even though they reflect most ambient heat, I think they also trap any internal heat. I much prefer a sheet metal baffle, with self-adhesive thermal barrier on the side facing the blasted headers. That leaves the starter in free air for maximum cooling, while still deflecting heat from the blasted headers. The only trick is how to secure the baffle if there are no bolt holes nearby that can be utilized.

 

Not sure I completely understand your terminology here. From the battery post to the starter case, you should see a maximum drop of 0.5. Remember, the closer to 0.0, the better. If I understand what you'e written, you're seeing a total of 0.6, which is slightly over the limit.

Please see post #245, where Dave has shown a ground cable from a 300-6. This ground cable bolts directly to the starter case via one of the mounting bolts. Even with that flag terminal in the middle, you have only the two terminals at each end to possibly reduce the current flow. I think that is a very good set up.

Compare that to the V8 version, where the ground cable bolts to the side of the engine block. (I can't remember if it has a flag terminal in the middle for the frame.) In theory it should be just as good to have the ground cable bolted to the block, but those poor electrons have to go through several junctions between the block and starter case. Having a brain fart, but doesn't the starter actually bolt to the bell housing, which in turn is bolted to the block, but separated by a big flat plate? That's something of a tortured path.

Considering you are having trouble with a slow starter, and your notes seem to confirm voltage drop out of specs with the ground cable, I'd suggest a new ground cable, slightly longer and bolted directly to the starter case via one of the mounting bolts. You may not gain much, but this may be a war of tiny increments.

For the frame ground, assuming you won't have a flag terminal in the middle, you can run a separate cable from the starter mounting bolt. This cable doesn't carry nearly as much current as the ground cable to the starter, so stacking those terminals won't be a problem. Just make sure when stacking the terminals, put the long cable (from the battery negative post) directly against the starter case.

 

Here's a homemade sheet metal version, as seen on Chevy V8, to give you an idea of what is possible:


https://www.thirdgen.org/forums/atta...d-p6090007.jpg


Another Chevy version:

https://www.ecklers.com/late-chevy/f...SABEgJ3M_D_BwE




Both would be even more effective with a heat barrier on the hot side:

https://www.thermotec.com/products/h...d-heat-barrier


Use the drop-down menu to see the various sizes available. I've used this stuff and recommend it highly.

 

Keep in mind starter motors aren't usually rated for continuous duty or anything like that, normally, the engine lights off pretty much instantly and that's the end of it.

Don't know what the "official" duty cycle is but I find changing starters unpleasant at best so I try to baby them and usually let a starter rest for roughly a "one minute rest one second cranking" rule if cranking for more than a few seconds. It's all tied together, a well tuned engine keeps stress off the battery and charging system.

 

Two corrections, on the ground to the block it showed .2, but when I went to the stud was .4. Nevertheless that was the total, it is now .2. I'll try to ground out the starter like the inline 6 engine, I just didn't know where to put it.

also, with the old battery, there was one instance where it was on the charger all night and had a slow crank, but since then, with new battery, haven't had the issue. All the motorcraft starters I've seen were remanny units, any preferred brand? Ac delco? Is remanufactured ford as good? I'll go back and re read actual load testing of the starter, but I replaced the starter out of spite, not because it past their test. I swapped it out with a new one just because.