Vauxhall Owners Forum banner

16v red top idle problems

3K views 21 replies 9 participants last post by  carman 
#1 ·
please help.

i have just bought ratty's champion gte 16v and it's a very nice car but i have a problem....it idle's at around 1000rpm when cold starting in the morning but as soon as it's warmed up the revs shoot up to 1400rpm and stays there :( . i work just round the corner from redline tuning so popped into see tony and pick his brain. he said to try changing the throttle sensor on the inlet butterfly and see if it makes a difference.

so i happened to have a 16v calibra parked up that runs perfectly so i swapped a few bits around, the throttle sensor and the air flow meter, and neither made a difference, it continues to race at 1400rpm. there was also a hose clip missing from the inlet pipe between the sfi box and air flow meter which i have replaced. according to ratty the engine has an enlarged throttle body and a carbon fibre induction kit, thats it. i don't know when the throttle body was fitted and if that would make a difference to the idling of the car, i should think it does, but then i should of thought it would have been sorted when fitted. has anyone experienced similar probs with their 16v red top engines? and what should i try next before taking it back to tony and leaving it with him to check out?

all help greatly appreciated, jon.
 
See less See more
#2 ·
jon i know this is no help but my LET does exactlly the same and i run larger injectors and larger fuel pressure regulator maybe this could be the problem to much fuel
 
#4 · (Edited)
Could be the ICV playing up (idle control valve)
Try swapping this over from the Calibra.
It sits just under the inlet manifold, a silver cylinder approx 4 or 5 inches long. (Has two hoses and a plug from memory)
Also check all of the hoses going to it as well as any other hoses from the airbox to the sfi box

Another quick check is that the throttle cable has not been incorrectly adjusted so that the throttle is always part open.
Try taking the small metal clip off (which stops the cable moving) and slacken the tension on the cable just to see if the revs drop.

Do a search for ICV to find out how to clean/re-oil it.
You will also find this is quite a common problem! ;)
 
#6 ·
i have the same problem on my mk2 conversion...idles at 1200....have tried changing lost of things but still not sorted...i have mounted the idle controll valve vertically beside the sfi box by swopping the pipes over...its much easier to get at now....be interested to know if u manage to sort this problem...
 
#7 ·
I think your throttle is partly (too wide) open during idle. Pinch the hose (close) running from the the ICV. The engine should die -- if not the throttle is partly open.There is two adjustment screws, one in front and one at the back(right) Check the accelerator cable as well. When the engine is cold the ICV can control the idle speed but when it hots up the ICV are not able to control the idle speed. Make sure your TPS is working - I think it is the case as you already swapped it.

John on your LET --> Running an external dump valve ??? Under idling is it closed or open ???
 
#18 ·
ok i seem to have a tiny problem. my car went to redline tuning yesterday afternoonfor a check out. 3 hours later there are no faults anywhere, no air leaks, only a reading to say the co was way to lean 0.15% and it wouldn't adjust on the afm.
as it is a cat version with a de-cat pipe the co is set by the ecu and non adjustable, and the car has an enlarged throttle body fitted which i can only assume will throw the air/fuel mixture out completely and you can't adjust it so it runs fast.

does all this sound right to anyone with knowledge of these engines and is my only way of sorting it a new mappable ecu or a standard throttle body, or could i get an older ecu and afm and adjust it????
 
#19 ·
thats the big problem when moding, your main problem is the throttle body, ecu is a good idea i once fitted the 2.5 ecu in my 2.0 cav the program made it run better for some reason then you could try the afm from the 2.5 and tweek it this might compensate for the large throttle body, just a thaught
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top