RussB

My car: 1988 5000CS TQ

Suddenly my car has developed a hot restart problem. I placed a fuel pressure gauge on the fuel filter outlet. After engine shut-off, I can clearly see that residual pressure quickly drops to 20 PSI and then slowly rebuilds (probably because of a good fuel accumulator) to about 35 PSI, then a second or two later drops quickly again, rebuilds, etc.

This cycle repeats three or four times, probably until the fuel empties from the fuel accumulator. The residual pressure remains at 20 PSI or less.

I can hear a distinct click with each sudden drop in pressure, and when I place my hand on the OXS frequency valve, I can feel it pulse.

It appears that the OXS frequency valve is erroneously being sent a current pulse, so it opens quickly and closes.

My next step is to swap ECU.

Has anyone seen anything similar?

dwengi

try unlplugging the connector to the freq valve just to be sure.