Soul crushed and seeking advice on starting problems

[lil_Blue_Ford]

Why do you say that? I am researching one of these as well, and kind of was partial to the ones w/o the pump as reading online that's the usual fail point (the built in pump).

The ones with the built-in pump, you don’t need anything special, just fill it with smoke fluid and connect it to the battery.

The ones without the pump require you to use an air compressor and a special regulator. Wouldn’t be a big deal if I had a garage to work on stuff in and shop air, but a hassle for working outside with little consistency as to where. My air tools have been collecting dust for years because of that, I’ve gone to being more mobile in my tooling ever since Milwaukee came out with the 1/2” high-torque M18 impact.

 

[holyford86]

Alright…

Little slow with my response because I’m working on cooking dinner…

Starter and bolts look better than I expected from that first pic. Unless the bolts are working loose it seems odd that it’s eating flywheels. Does it sound like it engages/disengages cleanly with no grinding?

Grounds can cause all sorts of issues even with cranking speed being ok. The normal place for the block ground is on the side of the block above the motor mount on these. Newer trucks take the block ground to the starter but anywhere block/starter/heads works. Normal configuration was a wire that went from the negative terminal to the frame and then over to the block. I usually run separate 4 gauge wires. That one you have on there all taped up concerns me about how well it’s doing its job.

The “dinky” ground wire is by the battery, just a short bit of 10 or 8 gauge running from the negative terminal over to the core support.

That is a super crusty pump! Yikes!

Wonder if the TPS (throttle position sensor) is acting up. More a curiosity thing.

Unplugging the IAC and it idles right tells me there’s a vacuum leak most likely.

That delayed spark sounds fishy…

@holyford86 , you have any suggestions?

I've seen missing engine to teansmission dowel pins or loose bolts cause issues like you've been having chew up ring gears.

Check your cranking voltage at the pcm and edis module to see if it's dropping very low during cranking.

Vacuum leaks shouldn't cause an issue during cranking unless they're giant leaks, which should be obvious.

As previously mentioned, it wouldn't be a bad idea to give the inside of the pcm a good look over for leaking capacitors or other corrosion damage. I had a couple failed or failing capacitors inside mine, it didn't cause anything super noticeable as far as driveability but the electrolyte is conductive and corrosive, which will short things out and cause issues or turn your pcm into a brick. It's best to catch them first. If you're reasonably good with soldering, a cheap soldering iron, a desoldering braid and vacuum kit, and some lead bearing electronics solder will suffice, and you can get it all at harbor freight. Digikey or similar has all the components you need from high quality manufacturers for reasonable prices as well.

 

[SenorNoob]

On the wiring, I was specifically thinking of the twisted pair shielded wire running between the EDIS and the crankshaft position sensor. Probably unrelated but is that sensor and harmonic balancer in good shape and clean? That could cause all kinds of issues. Especially if it causes the ignition to fire at the wrong time. I've even heard it suggested that hard start due to timing could cause flywheel/starter damage. I could believe it if the engine suddenly fired and started running hard enough.

I say all of that because a 91 has no signal to the tach without the EDIS module. And it pulls from the crank position sensor. If either has a problem it could cause the tach to jump like that. I wonder if a bad ground could have starting current leaking into the crank signal wiring?

 

[TacoBelleGirl]

Lots to reply to. I really appreciate all the insight you guys are giving me. Happy to have joined this forum and community!

I've seen missing engine to teansmission dowel pins or loose bolts cause issues like you've been having chew up ring gears.

Check your cranking voltage at the pcm and edis module to see if it's dropping very low during cranking.

I did all the work back in June but I don't remember missing any hardware between the transmission and engine. I can recheck later this week and see of things are still tight. I know I used thread locker on the flywheel / clutch assembly. Think I did the same on the transmission bolts too but I'm less certain on that.

I would also confirm that the starter has the right gear on it. The engagement is way less than it should be on the ring gear, not like the starter shifted a little, more like the starter gear has too few teeth.

Long shot, but also try to confirm that you got a manual starter when you replaced it. 4.0 starter's have slightly different "nose" lengths for manual and auto trans.

Okay. I just pulled the starter out of the truck the bottom bolt was very snug, the top one actually wasn't the tightest. Maybe 5 foot pounds on it? Oops. I do believe this is a manual starter based on the images I am seeing on RockAuto. Look right to you?

Having said that though - it does actually seem like the starter is making minimal contact with the ring gear when trying to turn the engine over. Attached is the current condition of the ring gear. In the position it is currently sitting, the flywheel isn't making contact with it and it is not turning over. The pics aren't the best, but you can see where only the tips of the ring gear are worn down. Other than that there's still a lot of each tooth there. Surely it can't be designed to only use that much of the tooth as a contact surface for cranking over? (P.S. See! I cleaned the plate before reassembly.. not the gunk inside the bell housing but I did clean the mounting surfaces lol)

Probably unrelated but is that sensor and harmonic balancer in good shape and clean? That could cause all kinds of issues. Especially if it causes the ignition to fire at the wrong time. I've even heard it suggested that hard start due to timing could cause flywheel/starter damage. I could believe it if the engine suddenly fired and started running hard enough.

The original sensor had a ton of oil caked onto it. New one is clean as is the balancer (probably flings any oil and crud off while running). It's actually one of the few clean spots on the engine. It had a huge PS fluid leak before I replaced the lines. Now I think it's got a bit of a rear main and the upper radiator hose has a leak.

I say all of that because a 91 has no signal to the tach without the EDIS module. And it pulls from the crank position sensor. If either has a problem it could cause the tach to jump like that. I wonder if a bad ground could have starting current leaking into the crank signal wiring?

Can I test that (without it cranking over correctly even)?
I have a pretty average multi-meter and a test light in terms of electrical tools which isn't that much.

Vacuum leaks shouldn't cause an issue during cranking unless they're giant leaks, which should be obvious.

As previously mentioned, it wouldn't be a bad idea to give the inside of the pcm a good look over for leaking capacitors or other corrosion damage. I had a couple failed or failing capacitors inside mine, it didn't cause anything super noticeable as far as driveability but the electrolyte is conductive and corrosive, which will short things out and cause issues or turn your pcm into a brick. It's best to catch them first. If you're reasonably good with soldering, a cheap soldering iron, a desoldering braid and vacuum kit, and some lead bearing electronics solder will suffice, and you can get it all at harbor freight. Digikey or similar has all the components you need from high quality manufacturers for reasonable prices as well.

Yeah I don't suspect a vacuum leak (or at least one to cause these problems for me), was just replying to someone else who mentioned it as I had commented on the idle sometimes being way too high.
I did already pull the PCM. No corrosion that I could see and all traces appeared to be intact. I replaced the capacitors anyways due to age and they did have a tiny bit of a bulge at the top.

And welcome to to TRS.

Thank you! I feel very welcome. Lots of people trying to be helpful and so far one has been nice. I'm really happy such a forum exists!

 

[TacoBelleGirl]

So I did check and I have 10 teeth on the starter. The flywheel I installed was this one from Orielly's. I don't know if that is at all useful info but I figured I may as well put it out there.

https://www.oreillyauto.com/detail/c/power-torque/engines---transmissions/transmission---transaxle/flywheel/cc087bdf6875/power-torque-flywheel/ptq5/nfw1118/v/a/5518/automotive-truck-1991-ford-ranger?q=flywheel

I can find a lot of people talking about similar problems and headaches but none seem to offer a real solution which is a bit disheartening.

 

[RobbieD]

I don't have a starter "nose" measurement, and I can't tell the difference manual versus auto starter by just looking at a starter. I'd need to see the two side-by-side to see the difference.

The only suggestion that I can think of, is see if there is a parts store nearby (maybe a "big box" chain store) that has both 4.0 starters in stock (manual AND auto), and see if they would let you come in and look at the two, comparing them to your starter.

That would also let you check where that thrust bearing, that stops the drive gear, is supposed to be (I'm not sure that it looks right). Replacement parts quality has gotten so bad, that you can't really rule out, that the new starter that you put on it, may have a wrong part put in it or be incorrectly assembled.

It's frustrating, I know, but don't give up. You'll get it squared away.

 

[TacoBelleGirl]

I don't have a starter "nose" measurement, and I can't tell the difference manual versus auto starter by just looking at a starter. I'd need to see the two side-by-side to see the difference.

The only suggestion that I can think of, is see if there is a parts store nearby (maybe a "big box" chain store) that has both 4.0 starters in stock (manual AND auto), and see if they would let you come in and look at the two, comparing them to your starter.

I can try checking around, but just comparing pictures all of the manual transmission starters for a 4.0 ranger on RockAuto have the same rectangular cutout that can be visible in my 2nd picture of the starter while none of the automatic ones have that.

That would also let you check where that thrust bearing, that stops the drive gear, is supposed to be (I'm not sure that it looks right). Replacement parts quality has gotten so bad, that you can't really rule out, that the new starter that you put on it, may have a wrong part put in it or be incorrectly assembled.

On the chance that it is a starter problem, you think there's any hope that flywheel will be fine? It feel like the starter isn't making nearly as much contact as it should be with the ring gear. There's some spots that are shaved down a bit, but overall I did not see a single missing tooth or even one that's chipped in half. Just a tiny bit shorter.

Also, should the bolts be able to have any kind of wiggle room in the starter? The bottom hole is quite snug around both bolts, but the top one I am noticing has maybe 1-1.5mm of clearance and the bolt can wobble around.
Seems like that would potentially allow the starter to be poorly aligned, right? Because that plate between the engine and transmission is just for spacing from my understanding and doesn't actually align the starter does it?

It's frustrating, I know, but don't give up. You'll get it squared away.

It is frustrating and it's hard not to get discouraged. I literally did all this work with the truck on jack stands out in front of my apartment, risking a getting into trouble. I did it on my back mostly by myself with a bad shoulder so I am really not loving the idea of doing it all again.