Rubbish MPG & Poor Idle

[timmaaah 0]

Hi all - been getting terrible mpg recently - gone from avg 28/32 to 20/22 mpg. That's off the mfi but the miles per tank has also dropped considerably. Had a blowing exhaust until recently, but that's now fixed. Car went for a service, and I asked them to check out the poor mpg - all they came back with is "sporadic faults found with lambda probe and acceleration sender". When I asked ofr clarification, all they said was "we don't really know what the fault is, but book it in and we can try and find it". When I asked for a rough price the response was "we don't know but it will probably be expensive" :roll: Also, my car has an electrical acceleration sender thingy? What the hell is that? I thought it was a cable throttle? If you rev the car, the exhaust will pop and crackle, like a small back-fire. Also the car is idleing really badly, sometimes stalling at traffic lights etc. It hunts up and down when you start it as well, but I think that's probobaly the isv needs cleaning? Can anybody please give me a rough clue? Thanks in advance

Timmaaah '94 VR6

 

edit: the car has a K&N cone filter but this was on the car when I bought it.

[steve @ 0]

Get it on vag com and get the error codes up. Does sound like you need a new lambda though, which is easy enough to change. Not sure what they mean by acceleration sender though LOL.

[CazzaVR 0]

Firstly, I'd take the car somewhere else. Sounds like this garage doesn't really know their stuff!

 

Maybe they meant engine speed sensor? Acceleration is via a cable to the throttle.

 

Sounds like you need a new lambda- my last VR had a similar prob when the lambda + wiring were damaged.

[Taggart 0]

He probably means the TPS?

[chigmuss 0]

In relation to your idle this sounds a little like the trouble I was having with mine (see low idle/cutting out) and after changing ISV which made no odds it was the MAF. The symptom I had was coming up to a halt in 2nd or 3rd the engine just smoothly died to no revs at all and would hunt badly at lights if it hadn't already stalled. If you're lucky enough to have someone who can swap their MAF onto yours to eliminate that it may be a wise route as they are F Off expensive from VW and 2nd hand aren't that cheap but it's always a risk using 2nd stuff.