McMiata Man

I bought an old Scooby last week and have been having some problems.

It's been cutting out and generally driving rough.

When cold, or after being switched off for 10 minutes etc, it takes a while to start it again.

I've put it all back to stock in the engine bay (removed Dump Valve, cone filter and refitted air box) also fitted new fuel filter and spark plugs.

Now, the previous owner has fitted a high pressure fuel pump, for no reason other than he had a spare 80 quid in his pocket.

Here's the theory bit...

Is it possible that the pump has wrecked the stock Fuel pressure regulator, so there's not enough pressure in the fuel rail?

It would also mean that any pressure the fuel rail had would disperse when the engine was off, and fuel would just drain back to the tank, thus making cold restarts take longer.

What do you think?

ianbott

The fuel pump runs for a couple of seconds when the ignition is turned on so to test your theory turn the ignition on for a few seconds then off then on again, do this a couple of times and it should purge any air out then try starting it.

Alternatively have you tried resetting the ecu as the ecu will have quite a few learning adjustments for the previous set up now all of a sudden it's all change for it.

McMiata Man

Thanks ian.

I tried priming the pump/fuel, but I fogot there's a deley between "primes". As in, I need to wait a few seconds before I turn the key again.

I did the ecu check yesterday and got some errors up.

23 - Mass Air Flow Sensor Circuit

24 - Idle Control System Malfunction
24 - ISC Valve (Stick)
24 - Open/Short in ISC Valve Circuit

12 - Starter signal

45 - Pressure Sensor

Then I reset the ecu, went for a drive and the engine checklight gave me the all clear.... even though it was kangarooing, lol.

I'll do another ecu check today and also try the priming thing properly.

Will report back later.