7.3 IDI starter issues... again

[Nick382]

Hello everyone! I'll try to run through the series of events so far...

Still working on my 1992 f250 7.3 N/A. I had replaced my worn OEM mistubishi starter with a denso styled unit from DB electrical just over a year ago. I had no issues with it over the past year, outside of weak batteries causing problems. Eventually it got to a point where the solenoid would "click" and not spin at all. I figured that my year old starter wasn't the problem, and this was a symptom of bad connections.

I bit the bullet and replaced every single one of my battery cables. I ran 000 for everything. After getting it all attached correctly, it did the exact same thing. Turns out the second DB starter had failed in a bad kind of way. Starter would test fine on a stand, but wouldn't spin at all. Frustrated with replacing starters, I decided to bite the bullet and buy the real deal. I bought an authentic Denso starter. My poor wallet...

Around a month later, the starter occasionally made grinding noises. The kind like when someone turns the ignition switch with the engine running. The starter motor wouldn't hesitate to turn, but wasn't grabbing the flywheel. The dual mass flywheel is less than 3 years old, and was NEW when I installed it. I've never had this problem with any other starter, so I have little reason to believe that it would be an issue with an aftermarket flywheel. Especially since it was a OEM Valeo DMF.

1. Is running a ground from a starter mounting bolt directly to the negative battery terminal a bad idea?
2. Did i just destroy my flywheel?
3. Would adding a relay between my battery positives prevent them from draining one another?

Outside of that, I guess I'll just have to drop the starter back out and inspect the plunger and spring for damage.

Sorry these posts always become long winded.

 

[IDIBRONCO]

1. It's not a bad idea, but seems to be kind of pointless to me. The starter is grounded to the engine. The engine is grounded to both batteries. I think it would be better to double check to make sure that your grounds on the engine are clean. I know that you recently installed new cables, but did you clean the block good before attaching the new ground cables?
2. The only way to answer this is to check out the ring gear teeth when you have the starter off (hope I didn't sound like a jerk on that answer).
3. Since a bad battery will draw down a good one, they should be replaced as a pair. Then, in theory, they will both be the same as far as good and bad. Batteries will also naturally self discharge at a slow rate so they eventually would be weak enough that they won't start the truck even if they're aren't hooked to either cable. I'm not sure that a relay would do much for you. It would have to be another diesel starter solenoid or a similar relay in order to handle and conduct the amperage that needed for the starter. If your batteries are both good and are being drained by something, you probably have a problem somewhere else.
Adding my own #4. Trying to start your engine with weak batteries is ******* your starter. I've burned one up (on a gas engine) this way. Maybe that was the issue with the second DB starter.

 

[ih8minimumwage]

Have you checked for a parasitic draw? How old are the batteries, and have you had them tested? If you're worried about one draining the other, you have at least one bad battery.

 

[Nick382]

My thoughts with the #1 is that the issue presented itself some time after I had a clean engine and mounted the new connectors. I made sure the surface was shiny, and free of any type of contamination. I didn't think a leak onto the outside of a connection like that could cause such a jump in resistance. I was also very unhappy when I discovered my OEM battery cables were corrosion free, and I spent a lot of money to upgrade cable size instead of fixing an issue.

In no way did you sound like a jerk, I was really just was hoping the pinion on the starter was softer than the flywheel. Doesn't really matter much as they're each like $500. I guess the starter is less painful to replace.

I've always replaced the batteries as a set, so I'm guessing I need to inspect my alternator wiring and/or the regulator. Since literally every component is new, I'm sort of scratching my head with this one. I haven't gone through and pulled fuses to check for slow draws, yet. Although there's no radio, so it would have to be something factory.

It's possible weak batteries killed it, but to me it seems like the gearset is what failed though. It's seized tight.

Edit: Both batteries were replaced with the wiring, and both were slow charged prior to being installed. They're cheapo batteries from Rural king (65-72 @ 850 CCA), so that could be part of my problem.

 

[ih8minimumwage]

Edit: Both batteries were replaced with the wiring, and both were slow charged prior to being installed. They're cheapo batteries from Rural king (65-72 @ 850 CCA), so that could be part of my problem.

Are the new batteries draining or getting weak after sitting?

 

[Nick382]

The truck has been my daily driver this year. So I'm guessing they're either draining or not charging correctly.

 

[IDIBRONCO]

At least the charging correctly is easy enough to test. If your connections are good (and I believe that they are) then all you have to do is to check the output of the alternator. And the draining? I'd say to unhook them, check the voltage and do a load test on them, then let them sit for a few days. Redo the two tests and see if the results are the same.

 

[ih8minimumwage]

A meter will tell you a lot (even a freebie Harbor Freight).

Let it sit overnight, pull the cables and check each battery voltage, should be close to the same. Hook everything back up, start the truck and check your charging voltage. Shut the truck off, and see what it drops too. Last check will still have a surface charge but give you an idea of what's going on if the truck runs an hour charging at 14vdc and almost immediately drops to 12vdc when shut off.

 

[Nick382]

Well, I can't get the truck to restart at all. It's in a spot where I can't work on it. I'm going to try to get a local to help me bump start the truck so I can drive it to its resting place to start tearing pieces off.

Anyone in southeast ohio with a truck that has too much free time on their hands?

 

[Bouncer]

Hello everyone! I'll try to run through the series of events so far...

Still working on my 1992 f250 7.3 N/A. I had replaced my worn OEM mistubishi starter with a denso styled unit from DB electrical just over a year ago. I had no issues with it over the past year, outside of weak batteries causing problems. Eventually it got to a point where the solenoid would "click" and not spin at all. I figured that my year old starter wasn't the problem, and this was a symptom of bad connections.

I bit the bullet and replaced every single one of my battery cables. I ran 000 for everything. After getting it all attached correctly, it did the exact same thing. Turns out the second DB starter had failed in a bad kind of way. Starter would test fine on a stand, but wouldn't spin at all. Frustrated with replacing starters, I decided to bite the bullet and buy the real deal. I bought an authentic Denso starter. My poor wallet...

Around a month later, the starter occasionally made grinding noises. The kind like when someone turns the ignition switch with the engine running. The starter motor wouldn't hesitate to turn, but wasn't grabbing the flywheel. The dual mass flywheel is less than 3 years old, and was NEW when I installed it. I've never had this problem with any other starter, so I have little reason to believe that it would be an issue with an aftermarket flywheel. Especially since it was a OEM Valeo DMF.

1. Is running a ground from a starter mounting bolt directly to the negative battery terminal a bad idea?
2. Did i just destroy my flywheel?
3. Would adding a relay between my battery positives prevent them from draining one another?

Outside of that, I guess I'll just have to drop the starter back out and inspect the plunger and spring for damage.

Sorry these posts always become long winded.

 

[Bouncer]

Just a thought.... I kept having starter problems, and Solenoid problems. Truck needed solenoid when i bought it, someone had stole batteries and battery cables, busting plastic case of solenoid switch. Replaced with stock switch from Advance. Kept having starter problems and Solenoid problems, Original style Mitsubishi starter tested good, replaced it with Denso, still having to replace Solenoid switches. Found out by accident that switch that Advance kept replacing was a 80 amp switch. Replaced with a 300 amp switch, Identical, just a hair bigger; problem solved!

 

[Nick382]

Just a thought.... I kept having starter problems, and Solenoid problems. Truck needed solenoid when i bought it, someone had stole batteries and battery cables, busting plastic case of solenoid switch. Replaced with stock switch from Advance. Kept having starter problems and Solenoid problems, Original style Mitsubishi starter tested good, replaced it with Denso, still having to replace Solenoid switches. Found out by accident that switch that Advance kept replacing was a 80 amp switch. Replaced with a 300 amp switch, Identical, just a hair bigger; problem solved!

That is an interesting point. Its the only component that has been a part of the system since the second DB starter. Even though i replaced the old component, it seems likely id get handed an underrated replacement. I think I'll check into that. Thanks for the advice.

 

[The_Josh_Bear]

Just a thought.... I kept having starter problems, and Solenoid problems. Truck needed solenoid when i bought it, someone had stole batteries and battery cables, busting plastic case of solenoid switch. Replaced with stock switch from Advance. Kept having starter problems and Solenoid problems, Original style Mitsubishi starter tested good, replaced it with Denso, still having to replace Solenoid switches. Found out by accident that switch that Advance kept replacing was a 80 amp switch. Replaced with a 300 amp switch, Identical, just a hair bigger; problem solved!

That's really interesting and a good piece of info! Thanks for sharing.

OP: if you end up pulling the Denso and find something amiss, instead of getting another new one see if you can find a shop around that can rebuild it. I haven't gone this route yet myself but it would be much cheaper than a $500 replacement. Many IDI'ers have suggested rebuilds over new with good success.

 

[Nick382]

The Denso is just over 30 days old, and the place I bought it from is honoring the warranty. Bouncers suggestion led me to ask about the draw on the trigger wire, and I guess it can draw 30 amps. I definitely don't see that original wire lasting long. But I'll hopefully have it apart today and see whats going on for myself.

 

[Nick382]

Well, I hope someone enjoys a laugh at my expense here... seems the early power strokes and IDIs have the same exact bolt pattrrn and bendix with a critical dimension difference. My new starter appears to be for the 94-03. I'm wondering if the automatics are different....

Flywheel doesn't have summer teeth, but definitely have some scarring on the edge of the teeth. Ive also damaged the starter so return isn't an option.

Yikes