Cold Start problem diagnosed... need some clarification

[mark '87 930]

I rechecked my cold control pressures and I was wrong the first time (or had the wrong chart. I have 2.7bar (40 PSI or so) cold (@17degrees C) which is off the chart according to my manual.

I don't necessarily want to make my wur adjustable (would more likely get a rebuilt one this winter), so I was reading about this 'plug' I can tap in a little... Is this the plug everyone talks about?



I'm also curious if there are any consequences to this process?

[mark '87 930]

Did some more reading.. and that was in fact the 'plug' Got my control pressure down to where it needs to be ... and voila. The car start cold with NO problems.. just like it used to.

My next question still remains though.. will there be any consequences to me having done this? In other words, as the temperatures rise and fall here in Canada, will that affect cold starts?

It sounds like in warmer weather, it won't be an issue that it starts rich, but in colder temperatures, what I did will 'help' it.. sound right?

[ruf-porsche]

Originally posted by mark '87 930
I rechecked my cold control pressures and I was wrong the first time (or had the wrong chart. I have 2.7bar (40 PSI or so) cold (@17degrees C) which is off the chart according to my manual.

I don't necessarily want to make my wur adjustable (would more likely get a rebuilt one this winter), so I was reading about this 'plug' I can tap in a little... Is this the plug everyone talks about?



I'm also curious if there are any consequences to this process?

The only consequences is if you tap the plug too far in, then you need to get it out. That is why people make it adjustable so that they can pull the plug out if the tap it in too far.

Your existing WUR is probably old and out of adjustment, tapping the plug shouldn't affect the warm start.

[mark '87 930]

Thanks for the note.

[Porsche_monkey]

Mark: I made mine adjustable, it's easy (in a machine shop), but I'm not sure it's worth the trouble. You do need to be careful not to drive it in too far.

The WUR is easy to repair. Scroll down throught this link where I posted an explaination.

WUR Vacuum Question

[mark '87 930]

Thanks Paul.

I actually tapped it in only when the fuel pumps were running and the CIS gauges (which I borrowed from Mike) were hooked up.. It was hard to move at first, but the pressure started to drop slowly with each tap.

I couldn't have done it without the gauges.

[hytem]

On the advice of my mechanic, I got a rebuilt one. Easy to install, and solved the cold start problem.