What were the cylinder pressures ? No you would have no idea what they were doing when retarding the timing.

 

The main indicator to me on the grounds, as pointed out to me, was that I keep burning them up.

i was draining the radiator early last year, parked in an incline, I went to start it with the good open and I noticed a whiff of smoke. And then it wouldn't crank over or nothing. I found the insulation burned off in a small 10 gauge wire going from the post stud on the firewall onto the bellhousing. I replaced it with a 4 gauge wire and it seemed to act normal after that. Whatever normal is....

before that, I had been using the winch and it would actually drain the battery enough to kill the engine, found a smoking ground wire then I replaced as well.

And before that that I had noticed a slow start and went to check battery terminals to make sure they were tight, and couldn't hardly grab the ground wire because it was so hot. These were totally unrelated times and issues, but could be a culprit. That's why I started counting all my grounds. And now I know my starter is actually grounded to a rusty engine plate and a pair of rusty bolts through an aluminum bellhousing.

Just thinking out out loud here.

 

Are all your battery cables 4 guage? Maybe you mentioned that before, but that is WAY too small for a big V8. Check out the recommendations from this manufacturer:


What size cable do you need


I'd say your truck falls under the category of a hard-to-crank big block, for which 2/0 cable is recommended. Granted, the author says that is slightly overkill and you could go down one or two sizes, but at the minimum that puts you at 2 gauge.

Now, one thing has me mildly puzzled. The voltage drop test (measuring the positive and negative cable runs end to end under load) should have picked that up. That's the beauty of the voltage drop test. Under load, a restriction from undersized cables will readily show up as being over the 0.5V limit. For example, when your old cables got hot, that means energy is being consumed. That would have quickly failed the voltage drop test, and probably showed several volts over the 0.5 limit.

But I think part of this can be explained if your Chinese starter motor is restricting the overall current flow in the circuit. Say a good quality starter motor should be able to draw 300 amps under load and turn that into useful output spinning the engine, but your Fling Dung can only draw 200. That puts less of a stress on the cable runs, too, leading to the misleadingly low voltage drop measurements. This is why in my voltage drop test write-up, I recommend repeating the complete test after making any repairs. A restriction in one part of the circuit (I'm theorizing the starter itself) can mask other faults in the rest of the circuit.

How to run the ground cable? Make it as direct as possible between the battery (-) post and the starter case. I'm not sure of the bolt arrangement, if you can put a terminal under a bolt head directly on the starter case. That's how I've wired some other vehicles and it has worked great. The factory would have kept cable runs to a minimum to save money (spread out over millions of vehicles), but for trying to gain every last bit of oomph for this pesky problem, make the ground cable run as direct as possible, even if that means spending a bit more on material.

Now don't just rush out like a drunken sailor and start spending big bucks on massive new cables. I'm pretty sure those 4 gauge cables are going to be way undersized, but that should show up when tested for voltage drop under load with the new Motorcraft starter installed. Then you'd know for sure.

 

Only cable that's 4 gauge is from firewall to bellhousing. Every other cable is 2 gauge. And brand new 2 gauge, with brand new connectors.

Ive taken for granted the fact that grounds go through the body to block and chassis indirectly, but something is indirect.

 

This is ground control... Come in.

Please go back to post #306 and read my heartwarming Tale of the Oomphs. When you grounded the coil lead to disable the ignition, you've made it easier for the starter to spin the engine.

With the coil grounded, you're not fighting the ignition (and resulting combustion) taking place before TDC, which is inadvertently trying to keep the piston from reaching the top of its travel. Now if there was a way to trigger ignition after TDC during cranking, that would actually help drive the piston down and spin the crankshaft in the correct direction. Instead, firing the ignition before TDC makes the piston want to spin the crankshaft backwards, and the starter has to work harder to overcome this.

 

Okay, phew!

When does your new Motorcraft starter arrive? If shipped via UPS, if you repeatedly click on the tracking link, it makes the package arrive faster. At least that's what I tell myself...

 

#2 or 2/0?

#2 as far as I'm concerned is the absolute minimum you should use on a non performance V8. And on 460 that is marginal at best.

I always default to 1/0 cables when redoing battery cables. And for Big blocks or Diesel's 2/0

I make my own as I have the tools to hypress the lugs on. The lugs get pressed and then soldered. The solder won't really wick down properly crimped multi strand cable but it does seal the lug and guards against corrosion in the lug.
Barring soldering then a generous coating of NOALOX or Kopper Cote on the conductor before pressing the lug on.

Again do you recall the PSI you were pushing when you were doing your compression test. ?

 

It is 2/0 gauge, I can't remember compression results off the top of my head and can't find a picture either. I can pull a plug and check tonight though.

so I'm giving up on wiring after installing starter? Where do i focus my efforts?

 

With 2/0 and proper installation clean and greased mounting points for lugs It would be safe to assume the start circuit is not the culprit. Since you are going to by pass the start relay all together it will be time to look else where.

The next place to look is timing/ignition system.

You still need to check to see if your damper has slipped it's ring.

 

 

When you say I'm going to be "eliminating the start relay anyways...." are you suggesting the problem could be in there still?

Is this a time where we reflect on what we know?

Battery=good
alternator=good
starter= Karl doesn't like, possibly bad
solenoid=Should be good? It's motorcraft???
wiring= good from pos side of battery to starter, negative on battery to block.I don't know about when the starter gets 12volts if it's properly grounded to block, but sure, indirectly, it's good. I mean....it's bolted to it.

still don't have body to chassis ground, or battery to chassis ground, but if it won't matter, who cares.

Back to the checklist.....

ignition switch to solenoid=tested once for 12v

actually timing adjustment= made no difference, if anything, when running 10-12 retard, it hard started more often out of 10 cranks, 6 were slow.

dizzy cap secured properly....

engine cranks over fine when coil lead is grounded.


what if if there was a retard feature in the box, and it were faulty?
Just kidding, but before we get into actually ignition, isnt that a can of worms in its own respective?

 

Anything anyone else has learned in the past 356 posts that would like to add to the list?

 

Yes. If the voltage to the electromagnet in the starter relay is weak, the contacts won't clamp together as tightly as possible. However, such a fault would have shown up when testing the voltage drop between the (+) battery post to the starter's (+) input.

You don't have to know exactly where it goes. That wire merely connects the battery's (+) post to the S terminal on the starter relay when the key is held to the start position. Just put your meter leads at those two points, key to start, and measure the voltage drop. Anything under 0.5VDC means the switch and related wiring is good.

Also check the negative side, too. The starter relay's actuating electromagnet is grounded through the inner fender, a sketchy path at best. Put your meter's black lead on the battery's (-) post. Put the red lead on the relay's mounting feet. Key to start, and measure the voltage under load. Once again, this voltage drop should be less than 0.5VDC.

 

I've taken the liberty of crafting two possible replies, depending on the outcome of the new Motorcraft starter. Just copy and paste one when the time comes:

Karl, you're a genius! Thanks for fixing this vexing problem. I'm embarrassed I didn't listen to you earlier. I don't know what I'd have done without you. Not only are you super smart, I bet you smell nice, too.

OR

Karl, you $%&#ety π¶∆# of %&€℅, why did I ever listen to you, you &$@#-sniffing piece of ¢€^¥., &€¥# you and the horse you rode in on, too. Go #&¥√π÷%$ yourself, followed by #%{=π€ @~π×∆=¥ with a #%+£¥€@. And then you can fish out the piece that broke off, turn it around, and shove it back in!

 

Have you actually confirmed it has not slipped ? It would not take much to mess things up big time. This would mean using a piston stop in cylinder #1
then centering the difference on the damper between the stop from clock wise and counter clock wise rotation stop of the crank.


Is it possible it is the start relay? Is it new ? ,if so then no.
if it is old then it is possible.

The contacts maybe making partial contact is if it is old.
See pic below of the contacts of one that was giving intermittent crank/no crank/slow crank

The load side of the contact wear away in time as does the contact disk eventually the 2 will not will not make clean electrical contact on the load side.

Also as these get used the contacts also get dirty from arcing, With the high starter draw it ensures they make a connection thru the crud, since there is no wiping action to clean the contacts they in part rely on high load to ensure a clean connection.

A lower load such as the starter solenoid on a PMGR or any solenoid fitted stater may not be enough to insure clean contact thru the start relay when the contacts get dirty. This is why I do not recommend using the starter relay to switch the power to the starter solenoid equipped starter. The existing ignition power feed to the stater relay does not have high enough amp capability to feed the solenoid on a PMGR starter alone.


What should be done is the the start relay abandoned, and a 30amp Bosch style relay used to switch battery power to the PMGR starter's solenoid. NOT the start relay.
The existing ignition power feed to the stater relay will supply the control voltage to the Bosch style relay