'82 240 d24 stalling- frustrated new owner

[Max]

Hello, all. just bought an 82 volvo 240 with d24. Car runs well while cold, but after 10 minutes or so, begins to surge and has no power, flat and then begins stalling withload, but will start and idle. Then after10 minutes or so will start with powerandthen will do the same routine within a minute or so. Frustrated! Compression checks fine, thermostat replaced, fuel clean.
Are there two fuel pumps? or one?

[m-reg]

sounds like sucking air in the fuel lines to me need to check for perished hoses or poss leaking pump seals

[v8volvo]

Replace the fuel filter if you haven't already. See if the fuel in the clear line from the filter head up to the inlet of the vane pump in the front of the IP is clear and solid, or has air bubbles in it.

How is your timing? Valves in adjustment? Did the issue arise suddenly or did the symptoms show up slowly over a long period of time. Need more details to be able to help much with this...

[m-reg]

some of the gassers had two pumps but I think diesel only has the main pump no lift pump does sound like lack of fuel and as the v8 man says tight valves could give similar symptom as they heat up an get tighter and loose a bit of compression