G60 engine management problem

[Shakel 0]

I converted the CIS-E system to G60 in my 2.0 16v Corrado (used OEM fuel rail, G60 ECU, wiring harness, CO potentiometer, idle stabilization valve, G60 injectors, blue engine temperature sensor, K&N free flow air filter and 3 Bar fuel pressure regulator for this conversion). I used wiring diagram downloaded from:http://www.gironet.nl/home/cillari/techinfo.htm.

the conversion ended up with two irritating problems: 1. Cold start problem, which can be solved only by disconnecting the CO potentiometer, doing that engine starts followed by small backfires. 2. When engine temperature is normal, rpm jumps up and down from 10000 to 14000, reconnecting the CO potentiometer do not help. I checked the ECU wiring about 20 times and all seems to be fine, checked for vacuum leeks- none, ECU vacuum line is connected to the throttle body, oxygen sensor is new, all sensors are grounded to pin #6 on ECU, ECU is grounded. What should be the problem? Is it ECU? CO potentiometer? Please HELP. Thanks!

[W3RKD 0]

to elimate the co pot from your problems...take it out and put a multimetre across pins 1 & 3 then turn the screw and see if values change... this is becoming a problem we are seeing alot of latley on g60's

[Shakel 0]

Thanks, well the co pot ohm values across pins 1 & 3 shows 1370 min and 1900 max...are these normal co pot values?

[G60 0]

doesnt sound like its the cause of any problems for you.. but make sure the TB to ECU line is *exactly* 3.5mm ID and 1m long. exactly.

 

and if you put a used blue temp sensor in there, go buy a spankin new one from the stealer. this will eliminate these two common issues from the possibilities. the fluctuating idle problem is usually a faulty blue temp sensor or isv.

[Shakel 0]

blue temp sensor is new from vw, ISV is used (chipper from a wracked car). turning the switch on i hear a click from the isv, isv vibrates touching it. disconnecting the isv from harness do not change idle... keeps hunting. I'll check the TB to ECU line length later. thanks!!

[G60 0]

i hope you didnt disconnect the ISV while the car is running... that might be your problem right there. that will fry the ECU.

 

i was about to go off on vacuum lines but you say those are fine.

 

if you can get your hands on a confirmed working ISV, put that on and see.

 

DO NOT disconnect the ISV with the car running. v bad.

[beavis 0]

Thanks, well the co pot ohm values across pins 1 & 3 shows 1370 min and 1900 max...are these normal co pot values?

 

 

It should adjust with in the parameters of min appox 250, maxing out at 1900 odd. Most cars fall within the 400-750 bracket when we set them up.

 

Is your car charged or N/A? If it is N/A then the ECU maybe trying to compensate for what is not going on.

[Shakel 0]

Hi there, just wanted to let you guys know that I really appreciate your help! I forgot to mention that I'm a new member here, great forum! :D

Anyway, I think that the problem is a defective ECU, I'll try to have some luck tomorrow installing a second ECU from my friend's GTI G60.

[Shakel 0]

Hi guys,

OK, I sort the idle problem. I made a mistake by not reconnecting the ISV intake air pip to the main air intake bore, I stupidly left the ISV intake open :oops: I drilled a new hole in the bore and connected the original 16V ISV pip in it sealed by a rubber ring. Last problem left is the ECU which is probably defected, it does not operate the ISV. Cheers