I have a 92 240 wagon, auto trans. When it starts it runs till I turn it off. It won't always start after that or before. In the morning it seems to start fine but in the afternoon it can be temperamental. Cranks just fine, just won't start. Eventually it will catch. Replaced coil, cap, rotor and spark plug wires thinking something was grounding out. Same problem.

What would allow it to start sometimes and not others but run perfect when it does start?

 

fuel pump relay. or maybe a dying main fuel pump (once it starts, it works, but the commutators inside are worn out, and sometimes it stops at a position where its not making good connection).

in the case o my daughter's 87 240, it was both :-O

 

Where us the fuel pump relay

 

I found it. Behind the glovebox. I reseated the connection and so far it has started every time. It has only been 3 times so far but it has started right up each time.

 

Typically the problem with these relays is there is a little circuit board inside them. Over the years, the solder joints holding the little coil in there crack and make intermittent connections. Just jiggling it around can cause it to work but it will fail more and more until you get a no-start condition. That could take up to a year or more.

If I were your, find a replacement. They only run somewhere around $35-45. Or if you are cheap and have a soldering iron, pop the plastic top off of it and re-solder the joints. Generally the re-soldered joints don't last as long as the originals but its easy to do (takes 10 min).

 

if you do buy a replacement, get the original Volvo OE relay, or the Stribel (they make the Volvo OE). the other brands are of suspect quality.

stribel's logo looks like a small circle with an S in it and two curved lines like )( such that the S almost looks like a $, and these relays are almost always white.