i've got a 1990 volvo 740 gle 16-valve that doesn't like to run in warm weather. when i turn on the ignition, the engine starts but the rpm falls quickly and so the engine stops. adding extra gas immediately after i start it let's the engine run but as soon as i remove it, it stops again.
if i do manage to get it running (at times when it is slightly warm), the engine has trouble idling or stops completely when the car is stopped in drive, but goes back to normal if i'm stopped and put it into neutral.
anyone have an idea as to what is causing this problem?

I had similar problem a few days ago. First thing I did was replace the RPM sensor. The insulation was eaten through causing intermittent failure.

Second, after this was fixed, I was still getting some loss of power at idle and sometimes under load. Checked the spark plug wiring at night, stood out that I was getting some arcing. Replaced plugs and wires, no problem (for)now...

jc
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1985 740gle na, 1990 740gle 16 valve

check the engine temp sensor

Tony,

I have the same model and same problem. Let me know if you get it figured out. My problem just got worse in that the car will not start in hot weather. I suspect a relay as now the sound of the fuel pump is not heard when I turn on the ingition.

Ron90740GLE

Hey guys,
Had the same problem. In hazy hot humid weather my 1991 740 would not start. Diagnosed it to be the fuel pump relay. Replaced the relay and put a colling fan on it as a precaution. There was a post about a similar topic a couple of days ago in which I went into depth about the relay system. A brick owner had a problem with his headlights, however I made my suggestions. A couple people took it into consideration and said they were going to work on it. I guess the stock relays on the 740 series were nothing to write home about.
Good luck,
steve