What are the symptoms of a failed warm-up regulator? - PeachParts Mercedes-Benz Forum

#1 07-09-2002, 09:38 AM

I've been throwing parts at my 450Sl for two months now and still can't drive it. It has been getting harder to start. Idling rough in D ok but not perfect in P. So far work I've done: Distr. cap & rotor, set timing to TDC, new addtl. air valve, cold start valve, thermo-vacuum valve, plugs and wires, coil, checked all vacuum hose against the diagram and all are in the correct spot and in good shape. I tried to set the CO/idle using my father-in-laws gas analyzer and can't get it below 6% CO no matter how lean I adjust it. Could my warm-up governor have failed. The car ran much better earlier in the year when it wasn't so hot outside. I would like to drive this car this summer but I cant get the thing to idle decently enough to sit at a stoplight without the fear of it stalling. I need help please.

mbz1 · #2 07-09-2002, 10:06 AM

I would try to set the timing at 10BTDC and see if that will help...

Where in Arkansas do you live??

Rob..

MikeTangas · #3 07-09-2002, 10:12 AM

When you set to 10*BTDC, do so with the vacuum line to the distributor disconnected and plugged. Once set reconnect the line, should recover to somewhere around 2-5*ATDC, that should do you right.

#4 07-09-2002, 10:31 AM

mbz1, I live in Joneboro on the other side of the state from you. I've set the timing to several settings vacuum connected and disconnected from 15 deg btdc to 15 degrees atdc with not much chance so I settled for TDC. Could it be my vacum advance on the distributor going bad? Still the problem remains; I can't get this car adjusted no matter how far I turn to leaner than about 5%CO.

mbz1 · #5 07-09-2002, 12:42 PM

hmmmmmm sounds strange to me i work on alot of those cars here in Russellville, and never had one to run that way I just wonder if has jumped time on one cam, that will make them run very bad i or it may be a pluged fuel filter not letting any gas get up to the fuel distribitor Do you know of any one that would toe it over here, i would love to get a chance to look at this on for in case i run on to one that is doing the same thing!!!

Rob

mbz1 · #6 07-09-2002, 12:46 PM

sorry i just noticed that you are saying it is running to rich does it black smoke?? if so then it in getting plenty of gas!! maybe the cold start valve is leaking all the time making it run to rich!!

#7 07-09-2002, 12:50 PM

Camshafts, timing chain replaced 20,000 miles ago. Fuel filter replaced last week also checked fuel screens on the distributor they were clean. Could it be EGR the diapragm seems to move up and down on accel. Could I disable it to see or maybe vaccum advance/retard on distributor?

mbz1 · #8 07-09-2002, 01:00 PM

I dont think the
EGR valve would do that.. they usually make the car go real lean and i usually do away with them and take the hose off and plug it That one is hard to figure out with out seeing the car.. wish i was closer to you i would love to help you with this one.. I think there used to be a mercedes dealer up there.. not sure.. good luck!

Rob...