[meinster]

Dave,

Yeah... we checked the Intake Air Sensor, though the symptoms are similar to what Tobra desribes, the unit seems to be functioning.

Whilst in the shop, she was permanently in her problem state, all checks performed were accomplished at that time. We spotted nothing that could cause this problem in itself! As stated there is an audible noise from the relays, but that does'nt seem to be affecting the performance, however will check again by substitution on Monday. The fuel pressure was on the high side, but also there, once we replace the fuel pressure regulator with an adjustable one, we found no improvement, so we reinstalled the old one!

I'll confer with Bill about the injector timing, in my Haynes book it stipulates the following... " At every second point opening (one full revolution of the crank), the control unit triggers all four injectors at the same time, but only half the required fuel is delivered per injection, therefor during every power cycle (two full crankshaft revolutions), two injections occur. Engine speed data is fed to the Control Unit from the rate of opening of the breaker points"

Both Dave and Bill were correct in the assertion that the injection cycle is incorrect, what could cause this?

This tells me (with my limited knowledge) that if it were a mechanical problem it could be the distributor itself that has odd play - not sure if that would be intermittent though, otherwise the metering of fuel per injection cycle is botched, this could be from a buggered Intake Air Sensor that has already been checked!?

The Control Unit looks like all the components in the car, it is 33 years old and a little weathered, however, we substituted other ECU's in there, with no improvement! It is next to the battery though, some serious corrosion there, thus the ECU may have been contaminated by acid?! The noisey relays are on the battery side as well!

We have attempted diagnosis by subtitution of many various components, few of those components we substituted are new, and may be giving similar problems... is there a reference on this site to proper electronic diagnosis (with multimeter) of the various components? My Intake Air Sensor has six pins!

I appreciate everybody's suggestions thusfar, the problem of course is one that causes secondary issues (extreme plug fouling being one of them - which begs the question, what are my valves going to start looking like if I keep running her like this?) so the sooner I can dispatch this issue, the sooner I can live happily ever after!

Thanks again
Pete