Hi guys

 

A few days ago I swapped my ECU chip from a TurboNoz Stage 1 back the the OEM one, to see the difference. The car mostly runs fine, and it might be my imagination but it seems a bit smoother and quieter which is nice.

 

Anyway the one problem I am having is with the car idling. When cold it idles perfectly, rock steady at around 1000rpm. As the engine warms it goes down to around 700ish, which I am led to believe is correct. After a bit more driving (maybe 15 minutes) the idle starts to fluctuate, sometimes dropping as low as 500 rpm. It also feels like it hesitates a bit from a standing start.

 

I was wondering if anyone had any thoughts on why this might be? I was also thinking that some adjustments to the timing etc may have been made when they installed the stage 1 chip? I'm gonna re install the chip on my day off and see if the problems go, but I would really like to use the original if I can.

 

Cheers

 

John

Most problems like that are either due to the temp sensor of the idle control valve - a poor electrical connection to either of those creates all sorts of odd effects.

Thanks for the info AndyP, sorry for the late reply.

 

I've checked the connector on the idle valve, seems okay.

 

I put the upgraded chip back in, the idle problem still persists so I've ruled that out. I have a few other things to check this week, but something crossed my mind earlier:

 

I recently fitted some bungs to my exhaust, that changes the volume of them. It brings the end pipe diameter from around 5 inches across to about 1 inch across. The exhausts are stainless steel and I think they have had the cats removed. Fitting these had the desired effect, and I haven't noticed any loss of power or performance with the car. I was wondering though weather this change could effect the idle running of the car, maybe due to changes in the air flow or back pressure.

 

I might be way off the mark here but I thought I would ask anyway, as they are a nightmare to remove and I don't want to pull it apart if it isn't going to make any difference at all.

 

Cheers for the input!

Hi, as Andy said check the ecu temp sender unit first (the two pin one on the front water pipe).

 

check the connector for corrosion and good contact. if that is OK you can check the resistance of the unit when hot and cold.

Cheers Medallion Man, I will check that. Do you know if its possible to get at the sender without removing the fan?

 

Cheers

 

John

yeah... top rad pipe coming out of the block... there are two temp sender units on it....

 

one is for the gauge (one spade) the other with two spades (on the right) is for the ecu... take the connector off and check it...

 

if it's OK and or if not and you clean it and still have the problem then undo the sender unit (or test in situ) :)

 

this any help?

 

Edited October 21, 201213 yr by Medallion Man

That's brilliant, thanks so much.

 

I'm off work for a few days now so I'll have a proper sort out and see if I can't solve it once and for all. At the moment it's not too major a problem, just irritating, but I feel it's the sort of thing that if left alone could cause other problems later.

 

Cheers for the help Medallion Man!

 

John