Quote:
Originally Posted by dieseldan44
I went through this week and replaced the rubber cap and the rubber hose connecting the vacuum line to the VCV. The modulator now holds vacuum over a very long period of time (went down 1mmHg after 10 minutes). 
Now connecting everything back up the system doesn't hold vacuum  (rack closed). I am using the MityVac testing right at the point where the vacuum that goes to the transmission comes off the main line. Plugging the output from the dashpot to the VCV with a golf tee holds vacuum fairly well going down 1mmHg every 30 seconds. So the VCV is leaking. I read up top that with the rack closed the VCV should hold vacuum or be replaced. Are there any adjustments, gaskets etc. to check before I invest in a new one of these (or go junkyard roaming)? Ill bring in and verify its operation on a bench as well before calling it toast.
This is now problem #4 in my tranny vac system debug extravganza  up till now theyve been cheap, i may not be so lucky here...
thanks - dd |
DieselDan44,
Unless I have missed it, you have NOT removed the VCV from the engine/IP and bench tested it all by itself and this is a relatively easy task. If you do this and you see leak-down results that indicate it is leaking vacuum much faster than I reported my 240D's VCV is leaking, then I would agree to the notion that you might have to replace the VCV... but not until then. AND IF you do have to replace your VCV, at ~$200 new, I would recommend that you try and find a used salvage yard VCV that holds vacuum reasonably well and is adjustable. I think that $30-$50 for such would be possible.
IF you decide to remove the VCV and bench test it, let me know and I'll pass on my suggestions.
Yes, these engine/tranny vacuum problems can be frustrating but they are NOT insurmountable... and yes for that plastic VCV to cost $200 might seem a bit of a rip-off, but price it at a Dealer's parts counter, I suspect it's noticeably higher there!
Note - That misadjustment of the idle on your IP could cause the VCV to bleed excessive vacuum... thus my current recommendation to remove the VCV from the car!
Regards,