My wife's 1980 245 died on me last week as I was driving it. No warning, was running fine, then nothing... I checked all of the fuses, and swapped the big one under the hood, still nothing. We pulled it to a local garage where they work on Volvo's sometimes. I called him the next day and he said it had started right up for them. He changed the fuel pump relay and we took it back. My wife drove it on short trips for a couple of days without any problems, then today she called to say that it was running rough and she didn't know if she would make it home. She didn't. It died at a stop sign and we pulled it home. Then after sitting for a few hours, it started and seems to run fine. Any ideas would be much appreciated.

Sounds really like a dead/dying main fuel pump.

What big fuse under the hood of a 1980?

Sounds more like a dying Impulse Sender. A dying pump usually cuts out and then never works again. Trust me on that. I've had both, and his problem is exactly like when my '81 lost the impulse sender. The fuel pump problem was slightly different, in that it made loud humming noises the day before, and then just cut out on me. Difference was, the tach needle moved when cranking. It also did not restart 2-4 hours later.

-J

Good point on tach needle...easy to check. But when the 85 fuel pump was funking out it would work for awhile and then quit for awhile...no loud noises either...

/// I don't know what he is talking about but I have come up on several old 200s that have a big blade fuse inserted in the system wire. This prevents a shorted alternator or wiring harness from causing a fire.

That happened to me last year in my 83 245. It is a diesel mind you but it turned out to be a wire molex in the engine. The sheathing around all the wires had corroded and they were making contact with each other.

/// Generally failure on heat up is bad electric contact. You did not say if it will turn over or just not crank. If it will turn over jump the positive system wire from the battery post to the distribution rail. If it will not turn over use you jumper cables to bypass the negative battery cable. Both clamps one end on the battery post clamp and both on the other end to the engine.

You can test the positive system wire by turning on the radio at the point of failure. If the failure involves high resistance rather than open circuit this test may not be certain.

These two may not be your problem but you should eliminate them before spending money on a long list of replacement "might be" parts.

Both tests must be done immediately on failure.

Bob-

These other posts are not aware that an '80 240 (in USA) has K-jet with Bosch electronic ignition. No MAF, no flywheel pickup. I still think it's either the pre-pump or the ignition pickup breaking down under high temps.

My 89 wagon had these symptoms last summer. Per the advice of the brickboard I focused on the fuel pump relay, first resoldering it and then replacing it. It didn't help. I checked the 700-900 FAQ and decided the problem sounded more like a dead RPM sensor. (BTW, I had also checked the AMM by disconnecting it: the car runs rough without it but when I plugged it back in the car was fine-so I eliminated it. You can find them for an 89 for about 275.) The RPM sensor for the 89 is on the bell housing held in plaace by 1 10mm bolt. Needed three extensions (6",6", and 3") on the ratchet to reach down in there but had the part replaced in an easy, greasy, half hour. Presto! Car runs like new. The sensor is ~50 bux from the dealer. One other thing: this malfunction will throw up failure codes on the onboard diagnostic computer that may indicate a bad AMM but you have to look at all the symptoms and decide for yourself if the AMM is bad or something else is acting up. I was ready to replace the AMM when I decided to make one more attempt and try this.

hmm.. it's hard to say much from your description,

but that is exactly what happened on my '88 245 when the Air

Mass Meter died. There is a procedure for testing the AMM,

although it won't tell you much.

the best thing to do as a diagnosis for the AMM is:

when it won't start try unplugging the AMM, and

then starting again.. if it then starts (will sound

awful, though) you may have a shot AMM.

It is located, by the way, on the conduit leaving the Air Box next

to the radiator. it's either black plastic or metal, and it will

have a large electrical connector.

hope this helps..

it's a $500 part, but I was able to get one out of a wreck at

the junkyard for < $10.

also: if it is the AMM, it might have been your Air Box Thermostat

that cooked it. either replace or disable it in any case, as a

bad one will fry the AMM in no time. it's the little thermo-active

cylinder inside the Air Box that moves the preheater flap doo-hicky.

A 1980 240 will not have a AMM. Nor will it have a "big fuse under the hood".

Next time it fails to start, check for spark at a plug. No spark, the hall sensor in the distributor is probably bad.

The only other thing I can think of off the top of my head is bad/abraided wiring to the main pump. The CIS injection system is pretty simple. It OFTEN has degraded performance from vac leaks and incorrect pressure, but it rarely stops dead.

What about a clogged fuel filter?

Onkel Udo

Bob-

Sounds like possibly the pickup in the distributor. You will need to duplicate the problem- sounds like it needs to be good and hot. Another possibility is the fuel pump or maybe the pre-pump in the tank. Does this happen at high ambient temps with less than 1/2 tank of fuel? This symptom would indicate the in-tank pre-pump.

Bob,

My 81 240 (K jet system) did the same. It turned out to be the inductive pickup in the distributor. It failed intemittently as you have described and then it finally failed all together.

At a different time, my main fuel pump started making a loud humming noise, I thought the pre-pump had failed and it turned out to be corroded electrical connections at the fuel tank access port. Check the connections before you open the tank to replace the pre-pump.

But right now, I think you may have a failing or failed pickup in the distributor.

Larry