M103

I am backfiring i think it's ignition timing. trying to find diagrams where this fabled ezl is. i think its not there is that possible? m103.940

Using chevron premium gas. In the US.

RBYCC

First is it "backfiring" from exhaust or intake ?

If you don't have an EZL your car would not be running.

Look left side ( drivers side ) inner fender area top wheel well behind the ABS unit and below the coil .

M103

theres nothing there im looking for a knob i can turn right? im looking between the abs, coil and fuse box theres no dials.

it sounds like its the cats. only on low rpms sometimes starting.

M103

i found it! but how do i adjust it?

theres no knob

looks like this http://cgi.ebay.com/ebaymotors/EZL-M...-/230298210548

there is a part above it with a knob like thing that screws off to protect it but there is 7ish pin slots but no way to adjust.

RBYCC

You need to obtain the maintenance or shop manuals for your car.
Foolish to try to make adjustments if you don't understand the ignition and fuel control on the M103.
The EZL in the USA cars is not adjustable.
Euro cars have a multi position adjustment that changes timing to account for lower octane gasoline.

Your backfiring problem is probably not due to timing.
You haven't indicated whether it's an intake or exhaust backfire.
Makes a difference.

Have you performed the basics such as plugs, wires, distributor cap and rotor ?

Also checked for vacuum leaks.?

Again all this information has been covered ad nauseum on this and other forums.
Search and you will find an answer and if not then post for assistance.

Difficult to help one that is not familiar with where the components reside in the engine bay

M103

all the info i have read was the European version, i didnt know the us was non adjustable thanks anyways... back fires at the cats
has new step down colder plugs (runs muuuuch better), new bosch wires, Distributor cap looks fairly new(used car), not sure about rotor.
If i cant change timing must be some tubes i really dont want to change cap and rotor. doesnt look easy like an old american car :/

lol looked up price like 60$ im still in mercedes shock lol.

RBYCC

What plugs did you install...manufacturer and part number...

Colder plugs typically aren't the best on older engines .
Depending on condition a hotter plug is more common.

You should always use the specified plug or it's equivalent.
Resistor plugs no good and newer platinum style with small diameter electrode can also be problematic.

Backfiring in the cats may be the plugs or something in the high tension circuit.
Doubtful it's the timing as the timing typically doesn't move.

You may not be getting a clean burn and some fuel may be igniting downstream of the exhaust valve.

When did the back fire start and what did you do/repair/mod prior to having a backfire ?

M103

NGK TR6, cant find any non resisitors where i live..
Been doing this for a while it is getting worse. i took a good listen i think its both the intake AND exhaust.

I bought this old girl used for 600, flat engine mounts etc ect. she is running beautifully but back fire in both cats and intake

M103

I just got the ticket of death from my mechanic. Bad rings, excessive crank case pressure