w201 wont start after sitting for year and half
 

My brother and I bought a non running 1992 190e last weekend. I was able to get it to get it to start, but shut it off to fix a loose belt. Well it wont start now. I drained the tank and fuel system and replaced the gas, New cap, rotor, spark plug wires and spark plugs. i have a spark tester and am getting great spark compared to how it was when it first started. I am getting fuel to the mechanical fuel distributor( cracked the lines while my brother by passed the fuel relay). I noticed that only one of the fuel pumps is making any noise and vibrating. Do these cars need both pumps to run? Also, it will back fire through the intake and exhaust after I crank on it for about 15 seconds. It gets super close to starting, but wont quite go all the way.

I'm really good with the old diesel benz's and the JDM motors, but this guy has alot going on under the hood. Any ideas would be a great help.

Thank you

What happens when you do not bypass fuel relay?

Did you replace fuel filter?

Vacuum leaks and lean fuel condition can also cause backfire.

Check ignition timing.

ej has it. Ignition components have been changed, and now there is spark at the wrong time. Time to call NASA; it's rocket science!

I didn't know the W201 had points & condensor

And that condition has not been rectified.

No points and condenser, but they do have cap and rotor. With new wires, it's possible that the firing order got mixed up, hence the calls to check timing and firing order.

Firing order possible

benzdude42, I am sure you realize that a Bosch distributor cap has the corresponding cylinder number on each terminal, so it shows the firing order. Cylinder No. 1 is in the front.

Does it start off of starting fluid. That narrows it down real easy. Yes, you do need both fuel pumps to run!

I don't believen you adjust the ignition timing on these motors after a quick Google search. I've checked the firing order a few times (1342) with no luck. I'll have to check it out for vacuume leaks next.

Did you check the vacuum hose under the intake going from the intake boot to the bottom of the Idle Control Valve? Make sure all of the ICV vacuum hoses, top and bottom, are in good shape and tightly connected.
I've owned my '93 since new, and the only time it failed to start was when the bottom ICV vacuum hose split at the connector. Replacing these hoses are routine maintenance.

Congrats on the new purchase! In case there are other systems that you're going to be restoring, take a look at the link below to our DIY articles. They should help you with maintenance and any other issues you may run into! Post a photo of the new ride man.

Mercedes-Benz 190 W201 (1984-1993) Technical Articles - Pelican Parts

In my experience a problem like this is usually fuel related. Do you have a pop tester from your diesel experiences? If so remove the injectors and see if you can get them to operate a bit better (!)

Modern fuel (over here anyway) has a fair amount of bio content in it these days which means the fuel separates after a while - the water content causes havoc with fuel components.

I wouldn't be surprised if you find you need to replace the injectors and all of the rubber parts.

Make sure that the start valve operates.

#######

Whilst you are fiddling with these KE II CIS systems make absolutely sure that the rubber hoses running from the underside of the mixture unit and the air idle control valve and the breathing parts from the crankcase are well seated and leak free. It is quite easy to know something loose and then spend the rest of your life wondering why it seemed like it was going to start and now won't...

...keep your battery well charged.

Sorry about the late reply. I've also decided it was fuel related, I am getting 90 psi at the fuel regulator, but no fuel coming from the fuel distributor. I took it apart to clean it and broke the diaphragm. Had the rebuild kit over nighted, Should be here tonight. Can the idle control valve control fuel flow to the injectors? I know the top hose I broken right now.