DEANO1969

iTrader: (1)

I have posted a few times regarding a problem I have, when ticking over and running at any speed the revs go up and down causing the car to seem like it drags back then goes forward then drags back etc etc.
I have fitted a new maf, fuel pump on order and fuel filter. I recently gripped my hand around the fuel pipe and noticed a heavy pulsing feeling () no dirty comments
Could this be fuel starvation problems?? as I said I will be fitting a new pump and filter, anyone suspect fuel relay?, idle valve? (But as I said it does it right through every gear and at all speeds!!??

Splitpin

We'll do the silly but obvious question first. Do you still get this on a full tank?

There are a few potential explanations for this phenomenon. Dodgy pressure reg is one, dodgy pump's another, dodgy fuel pickup is yet another. If it goes away when the tank's brim full that strongly points to the pickup.

Would also be worth walking round the back of the car when the engine's running and listening to the pump. If you hear the whine noticeably varying in frequency then that's further evidence - although there are still at least three distinct explanations for the pump to **** about.

madscoob

iTrader: (3)

rev counter going up n down sounds like hunting to me ide be looking for a air leak on the inlet side somewhere . with a air leak on tickover the car will hunt for fuel ie more of it as you have to much air going in cos of the leak , this maybe why the pipes is pressuring up n down as the pump is pulsing to keep up with fuel demand

DEANO1969

iTrader: (1)

Thanks for the reply guys, sounds good... Where exactly should I be looking all air ? pipes intercooler area? or all pipes in general? how can i spot a leak fairy liquid ??

madscoob

iTrader: (3)

air intake side after maf and all pipes on and connected to intercooler . wd40 will stop the hunting for a few seconds when sprayed on the leak , but you will have to be quick finding it