Hard to start when hot - Hamman Mod "Automated"
I am pleased to be a new member of TDIclub.com. I have owned my NB for a year now and this is my first experience with a diesel. I must say that out of all the forums that I have used, this one seems to have the most loyal VW owners that I have witnessed.
When I bought the car, the only complaint the former owner had was that the car was sometimes hard to start especially when it was hot.
I put up with this but figured that it was time to do something after throwing another P0380 code, believing that the hard starting and the P0380 were somehow related.
My 99.5 NB was about to get a bunch of new parts; battery, starter, glow plugs, glow plug relay, glow plug harness, $$$ etc...,
Then I signed up with tdiclub.com and came accross the Hammam Mod. I am no stranger to VW ECU's and wiring having performed several gas engine swaps.
I discussed the use of a push button with my wife and she didn't really get it. She drives the car more than I do, so I knew that for this modification to work, I had to automate the process so that she didn't have to worry about pushing a red button at the right time.
Today, I performed the modification but I substitued a simple relay for the prescribed red switch. I tied into the starter solenoid circuit as my trigger and it works. The engine isn't straining to start and there is no button to push.
I used this circuit as my trigger because I wanted to make sure that the 10k resistor was only active when the key was turned to "start".
Here is the wiring plan that I used:
1) Cut and connect the #3 wire (blue and brown or red) from the CTS plug to relay terminal 87a (Normally Closed).
2) Connect the other end of #3 wire to relay terminal 30.
3) Tap into the starter soleniod wire and connect to relay terminal 86.
4) Run a wire to a good ground from relay terminal 85.
5) Connect a 10K 1/4w resistor to relay terminal 87 (Normally Open) and then splice the loose end into the wire connected to relay terminal 30.
I hope this helps those who wish to tackle it.
The only question that I have is the effect on the starter solenoid performance with an extra little current draw to switch the relay.