MSefi.com read only forum (Jan.15,2018)

Well, I found out what happens if the limp mode relay is actuated through the accessory switch (correct) but the “B” "VRef" pin (correct) is hooked to the relays’ “87A” pin by mistake (NOT Correct) instead of pin "87". In other words the "Ref" signal is honked up. The the engine will try to run for half a second, every 2 seconds. But it will try to run terribly. You’ll know something is wrong. But it’s hard to find out "What" is wrong. It may even kick back against the starter, HARD. This may damage the flywheel starter ring. Yepper, mine broke. Heck, it even RAN BACKWARDS for about 2 seconds on the fuel that had been dumped into the exhaust. Boy, did it sound funny and loud, as it spit fresh fuel vapor everywhere!

Probably most people won't ever need or read this, this is just in case someone does have this terrible starting issue. It took me a long time to find it as I "Knew" I did everything correctly. And the schematics make it look like the timing would have just been advanced too far. Well, not so. Anyway, don't do what I did.

Holl

Holl,

Yeah, too much advance is a killer on starters. On my application (406cid SBC) anything more than 12 degrees advance while cranking would crack the aluminum nose housing on the OEM 'big block' starter. This allowed enough play that the teeth wouldn't engage properly, putting even more stress on them, and it was all downhill from there.

I had a pile of 8 or 9 of them at one time - all brand new, with just a few miles on them, but broken off due to too much cranking advance. Luckily the ring gear wasn't damaged by these events.

Eventually I ended up buying a bullet-proof aftermarket gear reduction starter, and setting the cranking advance to very near TDC, and haven't had any problems since.

Lance.