Hello,

I've recently had a couple of roadside breakdowns in my 1990 240 wagon

(B230F, LH Jetronic 2.4). Each time there was no fuel getting to the

engine, and the problem turned out to be the classic: the circuit in

the ECU (#561 - what a bad design!) that grounds the fuel pump relay

was fried. It was repaired once under warranty, and then replaced

when the same circuit failed again.

Now, with my shiny new ECU installed, I'm having another problem that

started immediately. When accelerating, or sometimes when cruising, I

get an intermittent loss of power. It's very sudden and only lasts

about 0.5 to 1 seconds, and sometimes repeats rapdily three or four

times.

The fault codes provided by the ECU are to do with loss of throttle

control and compensation for a rich/lean mixture (2-3-2 and 1-3-3 from

the ECU and 2-3-4 from the ICU).

My theory is that my fuel pump relay is bad, and intermittently turns

the fuel pump on and off, giving that loss of power. It would also

explain the destruction of the fuel pump relay circuit in the ECU.

What do you all think - is that consistent with the symptoms?

Also, it is possible to bypass the relay and have the fuel pump(s)

running by putting a jumper between fuses 4 and 6 at the fusebox. Is

it bad to drive around with this jumper in place to see if the problem

is indeed the relay?

Any advice would be much appreciated,

Chuck

p.s. this message was cross-posted to brickboard.com and alt.autos.volvo