I posted awhile back about rough idle and "pop" at startup issues that we are having with our 1991 245. The car is still playing up. It has a rough idle, the "pop" is still there at startup, and the gas mileage seems to be down. It is driveable but doesn't have the "power" of our 1989 245's.

The car has new plugs, wires, cap, rotor, Bosch wires, fuel filter, air filter, battery, AMM, engine temp sensor, oxygen sensor, intake gasket, speed sensor, flame trap and exhaust.

I cannot find any sign of a vaccum leak and all the electrical connections seem okay.

Here is the weird part: I cleaned the throttle body and the problem went away for a few minutes then it came back, I replaced the fuel pump relay with a known good unit and the idle problems went away then came back in a few minutes.

I'm not getting any codes.

The throttle body has the black plastic adjustment screw on it and I'm wondering if this is correct for a 1991? The 1989's don't have it.

Could it be the computer?

I'm almost at my wits end here any help would be appreciated.
Thanks,
-Len
--
Two 1989 245 Volvos and three Land Rovers a 1969 IIA, a 1991 RRC SWB and a 1995 RRC LWB!