Rev falloff problem.

[unity1]

As some of you the other week at Stoneleigh I had a boost and Reving problem. The boost seems to have been a stuck waste gate and is now hopefully solved. The Rev's however is a little odd and not what it first seemed. The syptoms are the Revs do not fall off (and can increase)once you release the throttle and press the clutch. The only way to reduce the revs is to brake and cause them to drop to around 800 rpm when it becomes stable. First Idea was a sticky cable and after a look in the Porridge pot carpark to find the adjustment 'tube' borken this seemed to fit. I have just looked at it and this is not the case. Yes the tube is broken but the cable is not getting stuck. I then considered dodgy carb springs so checked this and all was fine.

As a result it can only be an electrical timming problem. Anyone have any ideas on how to check/Fix this or other areas to investigate.

Steve
89 Turbo (That just wants to go faster)

[JohnWatkins]

Hi Steve,

Have you considered checking the float levels & needle valves?

If the fuel level is too high that could cause what you're seeing

Cheers,

John W
'95 S4s

[unity1]

No, but very good point. Wood for the tress kind of thing. Again shows how helpfull the group can be to kick around a problem

Steve

[hilly]

Have another look at the return springs as when the engine is off load you only need the throttle cracked open a very small amount to get a high idle speed.

I had a similar problem with the EFI conversion on my S3 where the last bit of return travel was slow as this is where the return spring is at it's weakest point.

Andy

[dave cardone]

I'm new to this; am I correctly reading that you have carbs on an 89 Turbo?

[unity1]

Indeed that is correct. You may have one with EFI.

Steve

[PatHeald]

My 87 Turbo HC has a throttle jack solenoid.

Does yours?

It stops the motor returning to tickover if you take your foot off the throttle. It is supposed to make for smoother shifts and to help the motor cope with loads such as the a/c.

I found it irritating, giving me a false tickover of about 1600rpm if I blipped the throttle, or coasted to a standstill in neutral.

I disconnected it.

Problem solved.

Worth a try?

Pat.