Throttle response - is it normal??
Throttle response - is it normal??
Author
Discussion

Ragtop

Original Poster:

592 posts

230 months

Sunday 22nd July 2007
quotequote all
Hi to all you fellow S owners out there. I'm a new forum member and an owner of an S3 for two days! This is the first of several questions that I hope someone out there will be able to help me with.
I bought my car aware of a 'sloppy' throttle response that I thought was just a simple matter of adjustment - now I'm not so sure...
The car starts, idles, revs and generally goes as would be expected. Idle speed according to the tacho is a little high at ~1000rpm. Initial experience suggested a lot of throttle pedal movement before anything happens. Further investigation revealed the following (all measurements taken from the centre of the throttle pedal):
0-8mm - taking up slack in the cable (ie 8mm of pedal movement before the cams/levers at the business end of the throttle cable start moving)
8-19mm - nothing happens at first then the revs DROP slightly (you can hear it, but not see it on the tacho)
24mm - Revs start to rise
115mm - full throttle.
So - I have a car that needs about an inch of pedal movement before it goes, and a long pedal travel to get full throttle (not that I really need it...)
The first makes smooth starts and gear changes difficult, and the second makes full throttle uncomfortable to get without taking one's heel off the floor.
My questions are:
1. is this typical?
2. what can I do to improve matters?

Looking forward to some response to all you S-heads out there!!

Martijn

52 posts

265 months

Monday 23rd July 2007
quotequote all
Welcome Ragtop, try this extensive thread:

Throttle Linkage Improvement

Usually the advanced search option will prove to be handy for the majority of subjects.

Good Luck and enjoy!

bil

123 posts

262 months

Monday 23rd July 2007
quotequote all
Having been at SCH and looked at the various engines on dislay i did note that the throttle plate on the S3 engine had a kinked plate ie with air flow meters and those above ie s3C had a straight plate. Not that this stops you from converting. some cable slack can be taken out using the plastic threaded connection as the cable connects to the engine. having replaced the throttle cable i need to do this to get the new cable set.

Ragtop

Original Poster:

592 posts

230 months

Monday 23rd July 2007
quotequote all
Thanks bil, and Martijn especially for the link. Sorry, with 419 pages of topics to plough through it's going to take me a while to find these gems!
Looks like a 'straight plate' is needed...

Jed-S

660 posts

245 months

Monday 23rd July 2007
quotequote all
Apart from the drop in revs what you have is where my car was before I tweaked the throttle plate as per that thread mentioned above. The drop in revs could be the throttle pot playing up or it could be that your ignition timing isn't setup correctly.

Martijn

52 posts

265 months

Monday 23rd July 2007
quotequote all
Regarding the drop in revs, think I noticed the same. Some Bosch Injection specialist told me that it had to with the type of airflow/mass meters used for this type of Ford engine and therefore was nothing to worry about. Furthermore, as soon as I made the car roadworthy and past import tests I started driving the thing.
Then I noticed that as soon as the engine is a bit warm the rev drop doesn't happen anymore. Don't know if yours also drops when the engine is warm?

stourbridges2tvr

395 posts

239 months

Monday 23rd July 2007
quotequote all
Martijn said:
Regarding the drop in revs, think I noticed the same. Some Bosch Injection specialist told me that it had to with the type of airflow/mass meters used for this type of Ford engine and therefore was nothing to worry about. Furthermore, as soon as I made the car roadworthy and past import tests I started driving the thing.
Then I noticed that as soon as the engine is a bit warm the rev drop doesn't happen anymore. Don't know if yours also drops when the engine is warm?
...What he said about the fev drop, same here.