P38A Wont run

95 4,6 auto 180k
Car hasnt run for about two weeks and when I started her today she rstarted fine but immediately died,
Very low fuel pressure at rail as fuel just ran out rather than spraying out umder pressure
Left ignition on for few minutes to let pressure build up if a slow pump but no difference.
Eventually after many attempts she started an ran fine, but then started cutting out again,
As I didnt know I had one, the fuel filter hasnt been changed for at least 120000 miles,
Could this have the crud solidified inside due to not running fpr a bit?
Nanocom showed no faults but air flow jumping all over the place.
Anyone any ideas please?
Thank you

sounds like your initial diagnosis might be a good start

I think there's a pressure relief valve somewhere to stop it overpressurising, I guess that could have failed. No idea where it is on these, might be integrated in the pump but some have one on the rail itself with a return to tank

Can you check the fuel pressure with an analogue gauge off the fuel rail just in case the fuel pressure sensor is out of whack?

Didnt know there was a pressure relief valve.
I will have a look for it
Dont have a pressure gauge.
I dont suppose a tyre pressure gauge would work?
Thank you

Do not use a tyre pressure gauge....must be a fuel pressure gauge or similar.

The pressure regulating valve is hidden toward the back of the plenum, under the throttle assembly....small diaphragm thing with a vac hose connected thereto.





It could be your MAF failing - if the MAF is unplugged, once the rpm gets to 500 the engine will die, unless you keep the revs above this value until the engine stabilises around 650-750 rpm.

Thanks for that Saint
I will check tomorrow

oakey said:

Thanks for that Saint
I will check tomorrow

Click to expand...

Usually if the engine will not run with MAF connected but will run with it unplugged the MAF has failed.

Never got the chance today so will try again tomorrow ta