Is this a fuel pump problem??

[DaveVR6 0]

I was driving along happily yesterday, in fifth, just gone down a hill so was letting gravity do its thing, when i got to the bottom and push my foot about half way down on the accelerator (expecting the car to take off a little) it just juddered and bucked a bit (like it was starved for petrol) i kept my foot in the same position on the accelerator and after a few seconds more of juddering and going really slowly it shot off again. then a bit further down the round (foot still in same position, on level ground now) it suddently slowed right down, so i pumped the accelerator and nothing happened it just sat at the same speed, no stalling or anything just sat at bout 30mph after a couple more seconds and me putting my foot flat to the floor it took off again...... could this be the fuel pump or is it some sort of sensor (hall sensor???)

 

Sorry thats a bit long, lol!!

 

Any ideas much appriciated

[Henny 0]

change your fuel filter... ;)

[h100vw 0]

Which engine are you running DM?

 

I have another theory that may apply to you.

 

Gavin

[G60 Bob 0]

I have similar symtoms with my G60. Gonna make sure the timing has not slipped and is 100% before i shell out on a new fuel pump so id really like to hear your theory if it applies to my motor?

[h100vw 0]

I am thinking about sticky throttle position switches. If you shut the throttle on to overrun and then open up again. If the closed throttle switch stays in the ECU will be confused, thinking you should be at tickover or cutting fuel off if you have a gear engaged and not be able to inject any fuel. The switch may free itself going over a bump or something and suddenly off you go.

 

Doesn't sound right, when I read that but I know what I mean.

 

The ECU is torn between 2 states. Overrun cutoff if engine is over 1500 revs OR tickover

 

With a G60 you should check the Vac pipe to the ECU if you haven't already. It should be a metre long exactly.

 

gavin

[G60 Bob 0]

It does sounds possible as the exhaust pops and burbles on overrun like the fuel supply is not shutting off but it is far more on and off than than that. Its most noticeable on part throttle or at low revs in highjer gears - just like the engine is starved of fuel or timing is being restricted (i.e. it initially lurches forward as if trying to repond then is held back)

When the throttle is pinned it goes at about 75% but acceleration is hesitant and revs rise very slowly compared to when she was running right. Vac hose was replaced less than a year ago and i had a qucik check and its fine. Throttle switch seems to click nice and cleanly on both closed and full throttle.

Could a faulty FPR cause this as i havent looked into it being the problem?

[h100vw 0]

A bad vac feed to the FPR wouldn't help. The Fuel Pressure should rise with boost, which is why there is a vac on it. Ign timing could be out too. It would probably run ok at small throttle openings but be unable to handle Larger ones. The timing would shoot up and the knock sensor could be influencing the ECU.

Gavin

[DaveVR6 0]

sorry yea, should of said... its a VR6

[h100vw 0]

You may have to discount my thoughts now as I don't know sweet FA about the running of a VR. :roll:

 

VAG COM check would be my first action.

 

Gavin

[DEL VR6 0]

its not the cam shaft position sensor is it? I had replaced mine on the rolling road say at stealth and it worked wonders.

[exturbo2003 0]

could be the coil pack shorting out maybe