Here's a classic problem. I am trying to figure out my ’91 240’s intermittent no start problem. This problem is continued on from the last owner who has had the car stall on him while driving as well as the no start problem. Whenever it happens I just jump the #2 to the #6 fuse and it fires right up. The car will usually start right up a number of times afterward w/ no prob. When it is having trouble, the check engine light will be off when the key is turned. I have tried swapping out FP relays to no avail, I’ve checked out both relays and they appear to be in good shape. Any ideas on where to start? Could an alternator on its way out be a factor by not supplying enough power?
Thnks Again, Justin

Your check engine light is off when the key is turned? Is it on when you are not having problems? Is the bulb burned out? Have you checked the computer codes yet? 1991 does have a black box, doesn't it?

Klaus
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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

Have you checked the crank position sensor located on top of the bellhousing?

I have not checked the sensor yet, so that will be my next plan of attack. As for the light issue that Klaus was asking about, the light is working but it just won't come on before it has one of it's "episodes".
Now I have tried to check the computer, but after I stick the pin in the socket and wait >1 <3 secs. I just don't get a message. thanks again for the replies guys!

"...but after I stick the pin in the socket and wait >1 <3 secs. I just don't get a message"

I think you misread the OBD instructions. You're supposed to push the button (not "wait") for >1 <3 secs.

Fuse 6 is the Main FI fuse. As long as the engine continues to run after jumpering from fuse 2,then fuse 6 is OK. I suspect it was more the physical contact at the fuse terminals that got it running, rather than the supplied voltage.

I would clean or replace fuse 6, scrape the fuse holder terminals clean, and squeeze them closer together for a more positive connection.

The RPM sensor is a good suspect, but I see no correlation to the fuse jumpering, if you are positive that's what works.

I don't think the alternator could be a no-start factor, as it supplies no power until after the engine starts.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.