Vts holding back below 3000 rpm

[saxoashlaughton]

Hi guys, I've got a mk1 1.1 that I've done a Vts conversion on and it seems to be holding back when driving under 3000 rpm but once over that the car picks up and goes fine, it also seems to cut out sometimes when I leave it idling for a while... It's got a walbro 225 fuel pump in and I've replaced the spark plugs and tried a donor coil pack and tried a different manifold pressure sensor and still seems to run the same, next step I'm thinking is fuel pressure regulator. Just thought I'd ask to see if anyone has had a fault like this before and found the problem ?
Cheers

[saxoashlaughton]

Anyone?

[SnakeVTR]

What do you mean by holding back? is it hesitating, missfiring or just slow to accelerate/pick up, if its just slow on pickup but runs fine then might be ok, most vts's are not great under 4000rpm, they really kick in at higher rpm though

[Gabbastard]

As above.

If its misfiring, chugging or whatever, try burying the throttle pedal. I cant remember at what point the ecu should disregard the lambda sensor but i seem to remember its roughly 4k. Im sure at w.o.t. it disregards it though, so if you try nailing it and it goes away it could be a lambda sensor.

[kyle4256]

Originally Posted by Gabbastard

As above.

If its misfiring, chugging or whatever, try burying the throttle pedal. I cant remember at what point the ecu should disregard the lambda sensor but i seem to remember its roughly 4k. Im sure at w.o.t. it disregards it though, so if you try nailing it and it goes away it could be a lambda sensor.

I think its the lambda sensor to !

[saxoashlaughton]

Some times old cars are.... Well... Exciting / annoying, guessing game really, but cheers guys, would it still cut out after idling for a while tho?