Is it possible to have pre-glow always? 1Z

[dieseljunkie]

I don't know why VW does not pre-glow the glow plugs when ambient temp is above 40F, but it does have a 2 to 3 minute post glow after the engine starts. Having pre-glow, winter or summer, gives a cleaner start. I have verified that by forcing a pre-glow by unplugging the coolant temp sensor, which mostly gets rid of the puff of smoke at cold start , and sets the CEL.

Is it possible to use VCDS to enable pre-glow always? If not, I'm gonna wire in a switch to simulate unplugging the coolant temp sensor(s) so I can have pre-glow in warm weather.

 

[Lug_Nut]

BK ECU: no
FA, GQ, JB and later: yes, sort of.
The temperature (about 40 F) can be modified through an 'adaptation' to shift the entire temperature upward resulting in pre-glow acting as if the coolant were colder.
Let's say you change the value and pre-glow now starts at 50F instead of 40F. Now when its at 40F the pre-glow time will be like it used to be at 30F, pre-glow time at zero will be as long as it used to be at -10F.

I find this adaptation handy when running high percentages of (less volatile) biodiesel.

The post-start glow is not time controlled, but is solely determined by coolant temperature (and engine speed under 2500 rpm).

Search, my friend.

 

[dieseljunkie]

I have the BK, so the only way for pre-glow is a switch. I did a quick test to see which sensor(s) I have to switch out. I hooked up a 20k trim-pot in parallel to the sensor that goes to the cluster, with ign on & eng off, it did nothing by varying the trim-pot from 20K to 0 ohms. With engine running, to my surprise, I was not able to vary the coolant temp gauge needle. I was only able to turn on the coolant temp LED with trim-pot turned to near 0 ohms.I will do more tests simulating both sensors at the same time.