Club G40 Forum

Technical => Engine and Transmission => Topic started by: G40 AD on May 02, 2011, 03:48:18 PM

Title: ISV
Post by: G40 AD on May 02, 2011, 03:48:18 PM
Just tried testing my ISV and found that the Ohm's stayed at 44.6 regardless of temperature, tested it at room temp and got 44.6 then held the valve in boiled water which resulted in the valve closing (visible by eye) but the ohm reading remained at 44.6... guessing its time to change???

I'm working through a few issues but the problem experienced is that the car is hunting on idle when warm.

Just wanted to get an expert opinion before giving in to the stealership!

Cheers,

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Title: Re: ISV
Post by: hayesey on May 02, 2011, 04:39:59 PM
The connector on it is just for 12v supply for it's heater. No point measuring it's resistance I wouldn't expect it to change.  As long as it closes when it gets warm then it's ok
Title: Re: ISV
Post by: G40 AD on May 02, 2011, 06:26:19 PM
aghh right cool... quickly running out of solutions to my hunting!! Just changed the inlet manufold due to one bolt threading to irradicate any vac leak, timed up to 6 degree's, CO2 pot set to 550ohm's... any thoughts?

cheers...
Title: Re: ISV
Post by: hayesey on May 02, 2011, 06:35:36 PM
Idle screw set right?
Title: Re: ISV
Post by: G40 AD on May 02, 2011, 08:06:02 PM
No not at present... no rev counter at the moment will try poppin in the G40 Clocks so that I can set the idle with the timing correct...

Tried retarding the timing which has stopped the hunting but it feels very flat, boost gauge isshowing 14-15psi so happy its not a boost issue...

Would it be likely that the hunting could be due to idle too high? In which case it would make sense that if the timing was advanced and idle screw wound down a touch this may be resolved...

cheers...
Title: Re: ISV
Post by: cheys03 on May 02, 2011, 08:34:15 PM
I've found when opening the idle screw it's a fine line between ~950rpm idle and aggressive hunting 1,000rpm up to 2,000rpm in a cycle every 3 seconds or so - almost as if you're stamping on the throttle. Does this sound like the issue, or do you get some different hunting?
Title: Re: ISV
Post by: G40 AD on May 02, 2011, 08:42:37 PM
yes this sounds pretty much what I am experiencing not sure if its quite as high as 2k but entirely possible as I cant tell with out the clocks in... gonna whack the clocks in tomo, re-time and set the idle... and see what happens!!!

fingers crossed...

Cheers,

Ad
Title: Re: ISV
Post by: cheys03 on May 02, 2011, 09:16:43 PM
2k was a bit of an approximation - it might be lower as you suggest.
Fingers crossed for you chap
Title: Re: ISV
Post by: G40 AD on May 03, 2011, 09:32:09 PM
God damn I love you guys sometimes!!! Bluey is back and I look like less of a twat sat at lights with out super rev's going on!!!

I was buzzing more than my ealry spec G40 Clocks!!!

Cheers agian as ever!
Title: Re: ISV
Post by: woody02 on May 03, 2011, 10:42:14 PM
Glad it's sorted! Been having a similar problem myself, what solved it in the end? Idle screw?
Title: Re: ISV
Post by: G40 AD on May 04, 2011, 09:10:48 AM
yeah mate - cant believe it made that much difference but had to wind it down ALOT! I literally went through everything on the car cleaning, swaping n tightening... really glad I did though cos found a couple of flaws along the way... had a nice play with a 330D BM this morn... GOOD TIMES!

I just set my timing to 6deg's then set my idle to 950rpm and its absolutely sweet... let us know how you get on mate...

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Title: Re: ISV
Post by: kickdown on April 19, 2012, 12:37:54 PM
How do you set the timing and the idle?
Any pictures are welcome. :)

I have these same symptoms on my car and it sounds like an easy fix.