Sr20det Hard to start when hot - Solved for $20

[PhopsonNY]

Hi All,
The hard to start Sr20det problem has been one that has plagued many of us for a long time. I have had this problem for a long time and tried may solutions. This solution that may help many of you… for $20
My symptoms were the car was hard to start when hot.
It started happening slowly and then became more frequent. It was so bad in the end that just on a hot day I’d have to “jerk” start it; jump start the car by sticking my left foot out of the door to rock it back and for then jump starting it… very annoying.

I even rebuilt my starter –
dyi-rebuilding-your-sr-starter-t385938.html
it worked for a while then the problem came back and I was about to buy a totally new starter;
http://www.frsport.com/Mishimoto-SR20DE ... 15385.html

Before you do spend any money, do a careful investigation by watching this video like;
http://www.youtube.com/watch?v=0mKrx-fM ... re=related
(this is the most comprehensive startup problem investigation video I have found)

I noticed that with a correctly charged battery, if directly connected 12v to the solenoid trigger switch, the car would start up every time hot or cold. Obviously the starter was not the problem.
The long and the short of it is that the I may car is 22 years old this year and the wires in the starter trigger circuit are old and have a high resistance when hot and do not send enough voltage to the starter solenoid. The solution I found was to use this signal as merely a trigger for a relay which would then direct 12v to the solenoid trigger.

The solution is fully described here;
http://forums.vwvortex.com/showthread.p ... k-problems
(the solution I used from the VW forum)
I would do a write up here, but the guy in the VW forum describes it so well it was not worth it.

Note:
Ultimately, the best solution would be to replace the wires in the starter trigger circuit, but I don’t have the time for that right now… maybe next summer.

Hope this helps somebody.

Cheers.