Greetings
No. 1
I have a question bout ignition module vacuum. If I apply vacuum to it with vacuum pump it doesnt change anything. I remember my old 420sel if you disconnect vacuum from module and seal both ends RPMs will go lower. With 300E if you disconnect and seal ends it does nothing. Is it suppose to be like it or my module is gone?
No. 2
Im fixing my vacuum leaks and found EGR valve membrane is leaking. I disconnected EGR solenoid and car seems to run a bit better since it doesnt leak vacuum on take off. Can somebody advise if its safe to drive without EGR valve working?

Original problem was hesitation to pick up speed,car accelerates very slow,give it 1/2 throttle it barely moves then jumps ahead like rocket, RPM drop down to 375 when put in D or R it even stalled couple of times, then RPM go up to 525 and stay there.
With vacuum leak found and mixture adjusted car seems to be better on acceleration.
Thank you
Victor

__________________
1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod

A full manifold vacuum signal is routed to the EZL module as is the idle signal from the TVS. The EZL is programmed to disable vacuum advance at idle, and it keeps the idle timing fixed at 9 degrees as long as the idle signal is received, and this idle timing value cannot be changed - at least in any way that I am aware of. The rate of advance increase with engine revs CAN be changed with different R16/1 resistor values.

If you raise engine revolutions to, say 2000, and check ignition timing (A dial back light works best for this test.) you should see about 14 degress more advance with the vacuum line connected to the EZL module compared to disconnecting and plugging it. You can run the test with a vacuum pump, too, but the throttle must be above the idle stop so the TVS idle signal is not present at the EZL module.

There should be no problems driving with the EGR disabled, but if you have to get emission tested before it's repaired, there's a good chance that you will exceed the NOx limits or fail a visual or functional inspection.

Duke

Thanks for info Duke.
Can I buy back light in Autozone to compare timing on idle and 2k.
I'd like to ask you one thing. Just curious. I disconnected vacuum line to EZL module on my old 420sel and it affected idle. You think something was wrong with ignition system on my old car? It doesnt matter anymore since I dont have it anymore. Im asking for my own curiousity since you know theory very well. You never know maybe Ill buy another 420sel.
Thank you
Victor

__________________
1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod

My dial back timing light is a Sears that is also sold under the Acton name. I don't know what Autozone sells.

The M103 balancer is marked to at least 40 degrees BTDC IIRC, and it can be read with a conventional timing light, but I find it much easier to use the timing light dial to turn the balancer notch back to align the 0/T mark on the balancer with the timing tab and then just read the dial on the light.

I've only researched the EZL operation on M103 engines. The V-8s had very similar systems, but I can't say for sure whether the 4.2 had vacuum advance at idle or not since I have not reserached it.

Go to the following link:

http://www.peachparts.com/shopforum/tech-help/117048-successful-ca-asm-emission-test-ke-fuel-system.html#post833484

In this thread I reference another link with results from the timing tests on my car that I conducted earlier this year.

I will also add the following caution. Further reserach indicates that the EZL alters the timing map - not exactly sure how - if the coolant temp exceeds 95C, and some of my data was with temps over this value, so I need to do some retesting will coolant temps under 95C.

Duke