Good old throttle/idle setup questions....
Discussion
So, having owned my Cerb for 15 years, I am still a bit s
t at setting up the engine. I know this topic has been well covered in the past, and I have been using the method in the thread linked below for setting up.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
However, I can't seem to get the adaptives to settle down no matter what I do, and always seem to end up with the slight hestitation on light throttle. Also, I can only seem to get the thing running reasonably with T-pots set at about 14.5% on idle. I have put an airflow meter on each cylinder and there is a bit of variaton at idle, but nothing major. Can just about idle with throttle stop wound fully in, so maybe there is a bit of wear on the butterflies? Can anyone see anything obviously wrong in the vid below?
https://www.youtube.com/watch?v=Z3FSH3ZnoI4
As you can see, getting a lot of vapour from the breather vent, is this OK/normal?
Probably should just get the car up to Joolz and get him to sort it, and get a re-map whilst I'm there!
t at setting up the engine. I know this topic has been well covered in the past, and I have been using the method in the thread linked below for setting up.http://www.pistonheads.com/gassing/topic.asp?h=0&a...
However, I can't seem to get the adaptives to settle down no matter what I do, and always seem to end up with the slight hestitation on light throttle. Also, I can only seem to get the thing running reasonably with T-pots set at about 14.5% on idle. I have put an airflow meter on each cylinder and there is a bit of variaton at idle, but nothing major. Can just about idle with throttle stop wound fully in, so maybe there is a bit of wear on the butterflies? Can anyone see anything obviously wrong in the vid below?
https://www.youtube.com/watch?v=Z3FSH3ZnoI4
As you can see, getting a lot of vapour from the breather vent, is this OK/normal?
Probably should just get the car up to Joolz and get him to sort it, and get a re-map whilst I'm there!
Edited by Toadusmodus on Sunday 4th October 17:08
Hi
Looking at your vid I can't see anything drastically different to mine, like yours mine runs better with lower than normal (18%) T-pot settings somewhere about 15.5-16.2%. If I set it up as per the manual it will be ok at idle but very hesitant around 2000rpm.
Couple of things which improved mine was getting my injectors cleaned (1 was partially blocked) and making sure when I put the air boxes on that they were properly sealed, I used some foam rubber draft excluder from Wickes.
Also the new software seams to exaggerate any fluctuations in the t-pots and will make mine jump about 2% this makes setting it up more difficult, the original TVR software is probably less sensitive and doesn't jump anywhere near as much, at least on mine anyway.
Your engine does look to be breathing quite a lot but some do, could it be ambient temperature and humidity that's making it look worse though.
Looking at your vid I can't see anything drastically different to mine, like yours mine runs better with lower than normal (18%) T-pot settings somewhere about 15.5-16.2%. If I set it up as per the manual it will be ok at idle but very hesitant around 2000rpm.
Couple of things which improved mine was getting my injectors cleaned (1 was partially blocked) and making sure when I put the air boxes on that they were properly sealed, I used some foam rubber draft excluder from Wickes.
Also the new software seams to exaggerate any fluctuations in the t-pots and will make mine jump about 2% this makes setting it up more difficult, the original TVR software is probably less sensitive and doesn't jump anywhere near as much, at least on mine anyway.
Your engine does look to be breathing quite a lot but some do, could it be ambient temperature and humidity that's making it look worse though.
Thanks Martin, any info is useful at this stage. Had another bash today, but haven't really made much progress. Going to buy 2 new T-pots just to make sure there is nothing weird going on there, but as you say, they do seem to jump about a bit on the new software. It's my only option now as the old Windows XP laptop I was using is dead!
LincsCerb said:
Hi
Looking at your vid I can't see anything drastically different to mine, like yours mine runs better with lower than normal (18%) T-pot settings somewhere about 15.5-16.2%. If I set it up as per the manual it will be ok at idle but very hesitant around 2000rpm.
Couple of things which improved mine was getting my injectors cleaned (1 was partially blocked) and making sure when I put the air boxes on that they were properly sealed, I used some foam rubber draft excluder from Wickes.
Also the new software seams to exaggerate any fluctuations in the t-pots and will make mine jump about 2% this makes setting it up more difficult, the original TVR software is probably less sensitive and doesn't jump anywhere near as much, at least on mine anyway.
Your engine does look to be breathing quite a lot but some do, could it be ambient temperature and humidity that's making it look worse though.
Looking at your vid I can't see anything drastically different to mine, like yours mine runs better with lower than normal (18%) T-pot settings somewhere about 15.5-16.2%. If I set it up as per the manual it will be ok at idle but very hesitant around 2000rpm.
Couple of things which improved mine was getting my injectors cleaned (1 was partially blocked) and making sure when I put the air boxes on that they were properly sealed, I used some foam rubber draft excluder from Wickes.
Also the new software seams to exaggerate any fluctuations in the t-pots and will make mine jump about 2% this makes setting it up more difficult, the original TVR software is probably less sensitive and doesn't jump anywhere near as much, at least on mine anyway.
Your engine does look to be breathing quite a lot but some do, could it be ambient temperature and humidity that's making it look worse though.
Check your throttle linkage rod ends for excessive play if you are having trouble getting to both idle and run on light throttle.
The throttle is pulled at one end of the rod and the idle stop on a 4.2 is at the other end. Play in the linkage means that you get the relationship of the butterflies and hence throttle pots changing as the throttle cable starts to open the throttle. This can mean that when you have it set up correctly on idle it all suddenly goes out of whack as soon as you open the throttle.
The throttle is pulled at one end of the rod and the idle stop on a 4.2 is at the other end. Play in the linkage means that you get the relationship of the butterflies and hence throttle pots changing as the throttle cable starts to open the throttle. This can mean that when you have it set up correctly on idle it all suddenly goes out of whack as soon as you open the throttle.
I don't think this is a prob on my car, the idle stop is the same side as the where the cable pulls (passenger side), and I long ago changed the ball joints to rose joints. The pots do seem to increase evenly and together. Thanks though.
Tanguero said:
Check your throttle linkage rod ends for excessive play if you are having trouble getting to both idle and run on light throttle.
The throttle is pulled at one end of the rod and the idle stop on a 4.2 is at the other end. Play in the linkage means that you get the relationship of the butterflies and hence throttle pots changing as the throttle cable starts to open the throttle. This can mean that when you have it set up correctly on idle it all suddenly goes out of whack as soon as you open the throttle.
The throttle is pulled at one end of the rod and the idle stop on a 4.2 is at the other end. Play in the linkage means that you get the relationship of the butterflies and hence throttle pots changing as the throttle cable starts to open the throttle. This can mean that when you have it set up correctly on idle it all suddenly goes out of whack as soon as you open the throttle.
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