'95 Ford Ranger grinding flywheel

In a matter of weeks, my truck destroyed two sets of flywheels and starters. When the ignition key engages, the engine "jumps back?. Apparently, this causes the starter and flywheel teeth to grind.



My mechanic cannot determine the cause of the “jump back”. He thought that it might be the timing. His examination and testing, however, proved the engine properly timed.



He is stumped.



Does anyone have ideas?

The timing is likely too high.

If this has a mechanically-controlled distributor and the mechanic determined that the base setting is correct, it’s possible that the vacuum advance is incorrect.

Before I knew much about how cars worked, I checked the timing on my old Buick and found it to be correct when checking, but the timing was still too advanced. I found that the distributor vacuum line was attached to a full vacuum port on the carburetor. Someone had attached the line incorrectly and I didn’t know enough to see that until after some research.

Distributor vacuum advance requires ported vacuum, not full manifold vacuum.

I doubt if something this new has vacuum advance, but I guess it’s possible. Or perhaps this information can be found applicable in a different way.

Thanks, Rod. This I’ll relay to my mechanic.

WX, Thanks for the thoughtfuly information. Monday I’ll bounce it off my mechanic.

Sincerely,

Ernie

If he checked the timing and it is correct…what exactly are you going to “relay” to your mechanic…he already did that… Hopefully he did it correctly…because this is textbook timing issue. On the 95 Ranger I believe you have a coil pack so timing isnt that easy to check…and it isnt adjustable…there may be a fault in your crank angle sensor…firing the coil pack at the wrong time… I dont think you have a distributor in th traditional sense…if you do have a distributor looking device then it contains the magnetic pickup that sends a signal to the coil pack…this can be malfunctioning…something seems to be triggering your coil pack at the wrong time…for all of us to say timing right off the bat…

Also maybe one of your wires is leaking into the next…firing the wrong plug at the wrong time…another thing to look for…you can check that theory at night…run your engine and look for fireworks along the wires…if you see any you need wires.

I thought of another thing it could be…perhaps your starter has shifted and now is engaging the flywheel to deeply…making it hard for the starter to back out its gear from the flywheel…they sell starter shims to help with this…

Blackbird,

Having possibilities feels much better than being stumped. Once my mechanic explores your wealth of ideas, I’ll send you a report. Thanks.

Ernie