Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Paul M]

I have the 98 cable-driven throttle, and sometimes when driving slowly when you have to take your foot completely off the accelerator (but still in gear, with the clutch up) you can feel the engine hold the car back as expected - I believe this is called overrun and it's designed to cut off the fuel during this time as the momentum of the car will keep the engine turning and it also helps with engine braking.

However, the problem comes when re-applying the throttle. Instead of it smoothly re-applying power, you can press the pedal a little and nothing happens, then all of a sudden the power comes back but because the throttle is already open a little it causes the car to surge. This is especially bad in lower gears for obvious reasons - the weight of the car having less of a damping effect on the engine output - but is noticable even in 5th gear.

I've checked both the cruise and throttle cables, both appear to be correctly adjusted: the throttle returns to the closed position with almost no slack left in either cable. My other concern is the throttle position sensor giving dodgy readings around the closed position leading the ECU to think the throttle is still closed after it starts opening. Has anyone else experienced this kind of effect, and what was the cause?

As well as being annoying it can be a nightmare in sharp corners in the wet especially with my awful tyres, a sudden jolt of power is not what you need in those conditions!

[TheBoy]

May be worth sorting the tps, in case ecu to thinking you are opening throttle more than you are, hence giving it a nice rich blast...

[Admin]

I suspect the throttle butterflies are caked up with carbon deposits.

Remove (note position of TPS), drown in carb cleaner and refit.

Actually you may as well clean the whole breather system at the same time.

[Paul M]

Should have added, I gave the throttle bodies (and breather system) a good clean out about a month ago. They were a bit black but not caked with stuff, certainly not enough to make the movement sticky. No noticable difference in driving.

[Taxi_Driver]

Not that this really helps your problem......but you can tell if the fuels been cut.....Have the comp showing instant fuel consumption.....if it displays 999.9mpg then the fuels been shut off....anything else then its still feeding the fuel.