car runs, then stalls
 

My 1980 244 DL (CIS) starts cold fine, runs for 5-10 minutes, then dies and won't restart until it has cooled down for about 15 minutes. After "warm" restart it only runs for a minute or two. Any ideas?

when it won't restart, you need to determine if its spark or fuel.

Yes, I will check. But I did notice that when it has stalled and won't restart, I don't hear the main fuel pump running.

ah, then maybe its your fuel pump relay, OR your hall sensor (in the distributor, provides timing signals to the ignition AND the fuel pump control unit, so the pumps only turn if the engine is turning).

if you also have no spark then I'd check the hall sensor.

do you have a tachometer? does it twitch when you're cranking when its in the 'no-start' condition? if it doesn't, and just sits at 0, thats a good sign the hall sensor is going thermal on you.

No Tach. Fuel pump relay was replaced a few weeks ago by previous owner when it wouldn't start cold. I will check for spark tomorrow if rain holds off. If spark, then I am back to main fuel pump?

or the relay, I dunno.

I'm not very familiar with Volvo's that old, I've only worked on 87 and newer LH 2.2 and 2.4 cars. I'm heading out right now but if I remember, when I get back to my computer I'll look and see if I have the schematics to that year and try and puzzle out the fuel pump circuit, see what triggers it. on LH cars, the pump only runs when the engine is turning over, the hall sensor (or crank position sensor on LH2.4) goes to the ICU (ignition control unit), and the ICU forwards it to the ECU (fuel injection control unit) which triggers the fuel pump relay.

if you have a 12V test light, you could probe the '1' pin of the coil and have someone crank when its in the no-start condition, and the light should blink, that would indicate you're getting timing, and as long as your coil/cap/rotor/wires are in OK shape, its hard not to get spark when you've gotten that far.

OK. No problem with spark (there is a sensor on the distributor), so I will begin to troubleshoot other FI sensors.

Did you get it going? Crank position sensor failure has these symptoms, as it is temperature related.
Also: any electronics in the ignition system.

There is no crank position sensor on '80 models. CPS started with LH2.4 fuel injection system in '89. I don't even know if '80 models had the Hall sensor in the distributor for FI timing. The '80 models had the K-Jet fuel injection which I know next to nothing about.

on the CIS-E (KE-Jetronic) cars, the distributor has a hall sensor, but its just used for ignition timing, if you have spark when its in the no-start condition, then the hall sensor is working fine.

my CIS wrenching has been limited to a 1990 Mercedes 300E, which is a 6 cyl but fairly similar to what Volvo used... when you first start the car cold, it runs open loop for a minute or so until it heats up, and on the rich side, then the 'lambda' circuit switches on, it monitors the exhaust gas free oxygen content, and uses the 'control pressure regulator' (on the Benz, its the EHA or Electro Hydraulic Actuator) to modulate the fuel pressure to reduce the gas pressure to maintain stochastic mixture.

The major problem our 1990 MBZ had turned out to be old injectors that both leaked/dribbled when they shouldn't, and had a bad spray pattern, combined with leaking seals so they let too much air in. the car started and ran ok cold, but as soon as the lambda cycle cut in, it became erratic, and would stumble and stall. The injector seals on that car were 2 pieces, a o-ring and a plastic sleeve. again, I'm not sure how directly applicable this is to Volvo K-Jet.