Hi, can anyone help with clues to lost fuel pressure ?
Engine starts and runs fine up to 1800 rpm or so, then splutters and falls over, like its lost fuel pressure.
Its a 99 lightning, looking at the posts they had a few issues with spitting the fuel lines off the pump. Its also done over 150 miles and never been apart.
Many thanks if anyone can shed light, no one has a clue in New Zealand.

 

Here are a few ideas for you to look at:

1. I have heard about fuel pump relays going bad on those year Lightnings, causing a loss of fuel pressure.

2. Change your fuel filter. You may find that may be partially plugged with debris.

3. Are there any DTC codes? You might have an injector or injectors leaking fuel. Might just want to have the injectors cleaned and tested.

 

Thanks for the reply.
Tried the filter first off, no change. There is 13v at the pump with no pressure, but fault code it has thrown up is the fuel pump relay. Will a bad relay still give voltage at the pump ? Or have I got the metre across the wrong poles ?

 

Yes, it is very possible to have voltage at the fuel pump constantly if the relay switching arm is stuck in the "constantly on" position due to sticking contacts. You could also have had the metre measuring the voltage across the relay coil; that would read the 13V the metre read.

I would replace the relay at this time, as that seems to be where the problem is. Hopefully, it doesn't cost to many NZ$ for a fuel pump relay.

Good luck.

P.S. Whereabouts in New Zealand are you located at?

 

Will do, thanks for the advice.
I'm in Auckland, out west. Its probably like the States ? Little bit wild, locals have funny hair cuts, not allowed a gun rack across the rear window though