I have a 1991 Volvo 240 that has spark,pulse,fuel and will not turn over. The car does start every once in a while and then will not start again. I have tried the crank sensor, fuel pump relay and radio supression relay and also the Ignition Module/Amplifier, none of these have made it any better. Anyone have a guess?

If you're making spark, the crank sensor and ignition power stage are good.

I'd check the timing belt and as lucid says, check the timing marks.

I've seen a couple examples lately of timing covers falling apart, pieces going down inside, screwing up the timing belt or making it jump time.
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Rob Bareiss, New London CT ::: 92 244-M47-207K ::: 90 745GL-M47-268K ::: 88 245DL-AW70-230K ::: 88 244 SOLD! 87 244 SOLD! Still looking for a bright red or black 244 with sunroof...

"I have a 1991 Volvo 240 that has spark,pulse,fuel and will not turn over."

I'm guessing "will not turn over" means it doesn't "fire" but cranks OK. I'm not sure what "pulse" means either. But if you really have spark and fuel, the only thing missing is compression — or spark when compression occurs.

Make sure the belt is turning the camshaft, and if so, that it hasn't jumped a few cogs (check for cam and crankshaft being in sync at 0° for #1 timing).

P.S. I don't think you changed a "radio supression relay" as that's only found on 700/900 cars as far as I know.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Hopefully it is not the AMM but here goes...

I've got a 1985. Earlier this summer -- wouldn't start. Unplugged AMM -- Started right up. Ordered used OEM one for 40 US bucks on ebay... plugged it in and problem solved.

You don't mention the basic diag for the AMM, disconnecting it. I can make a pretty good guess it isn't the radio suppression relay.

Ditto on that thought... seems like a lot of folks are losing AMM's this summer.

Just don't disconnect the AMM when the car is "on" (turn the key off).

-Ryan
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Athens, Ohio -- 1990 245, 125k, M47, E-codes -- 1991 745, 278k (girlfriend-mobile)