W201 m102 wont start, at all - PeachParts Mercedes-Benz Forum

szamik · #1 05-23-2017, 09:30 AM

Hello.

Folks, I need some advice

I am trying to start my friend w201. It has new m102 2.3 engine because old one was running rough (broken head). Car was in few mechanisc but nobody is able to start this car...

I thought that there is some problem with KE-jetronic. I know this fuel system quite well but unfortunetly it seems to running well. Now how it looks like:

Engine:
Doesn't want to start at all. It was running well in previous car so I am sure that it is in good condition but also I have made a compression test. Each cyl about 180psi

Fuel:
I think it is not the problem, injectors are spraying well, fuel pressure in distributor about 5 bar, cold start injector is also spraying fuel while cranking. ICV is also alvie I replaced every vacuum hose. I'm sure that there isn't any vacuum leaks. Engine also doesn't want to start if i put some fuel directly on throttle body so... ignition?

Ignition:
I replaced CPS, ignition module, coil. Rotor, cap, cables and plugs are brand new. Strong spark is present on each plug. I have checked position of rotor at TDC twice or more time... It is set correctly - matching to the cyl 1 at distributor cap so I don't think that there is a problem with ignition at all. So where...

I am not sure about one thing. I connected strobe light into 1 cyl ignition cable and while crancking, ignition is exactly at TDC mark? I am not sure, is it correct? I think that it should be about 10/15 degree bFTD.

What do you think?

Thanks for any help ;-)

liquiddog · #2 05-23-2017, 09:36 AM

Check the large vacuum hose connections going into the intake. If any of those are unplugged or split the car won't start.

szamik · #3 05-23-2017, 09:41 AM

You mean this yellow one which is going to brake pump? It is connected.

liquiddog · #4 05-23-2017, 10:02 AM

They are large black hoses connected to the IAC check all connection points.

szamik · #5 05-23-2017, 10:08 AM

Oh those hoses... Yes I know. As I said, I have replaced all of those hoses. That "u" shape under ke jetronic also.

liquiddog · #6 05-23-2017, 10:12 AM

Just suggested it because every time I take off those hoses I always miss one connection when putting them back on. And it doesn't start.

Maybe not the issue. Just a suggestion.

szamik · #7 05-25-2017, 02:01 AM

Do you have any ideas?

liquiddog · #8 05-25-2017, 08:52 AM

It sounds like you pulled the engine in known running condition and swapped it into your car. Now it cranks but won't start.

If you still have the old engine, start looking for electrical connectors in hidden spots that you may have missed? EHA plugged in, etc. Even simple things like the wiring to the distributor from the coil, the coil being hooked up correctly, wires in correct order, etc.

optimusprime · #9 05-26-2017, 06:11 AM

What is the condition of the spark ? You can get a weak spark not enough to ignite the fuel if coil is down . Are the ht leads on the distributor in the right order ?

optimusprime · #10 05-26-2017, 06:23 AM

Is this like your set up . Let us know please .

liquiddog · #11 05-26-2017, 11:40 PM

Please do let us know what it ends up being. Always good to know what the root cause was.

szamik · #12 05-27-2017, 03:03 AM

Quote:

Originally Posted by liquiddog

EHA plugged in, etc. Even simple things like the wiring to the distributor from the coil, the coil being hooked up correctly, wires in correct order, etc.

Every plug is connected I am sure, but even if no - car must to start for a few second if I put some fuel directly to the throttle body. I also said in first post that I have spark on each plug so that mean coil is also connected proparly (I replaced it too ).

Quote:

Originally Posted by optimusprime

What is the condition of the spark ? You can get a weak spark not enough to ignite the fuel if coil is down . Are the ht leads on the distributor in the right order ?

I said in first post that the plugs, cables rotor and cap are brand new (Beru). I am sure that ignition is in right order. Checked it few times but (unfortunetly) this is not the reason of my problem

optimusprime · #13 05-27-2017, 05:38 AM

Yes i know all about it ,, but it could be firing on the dead stroke so spark in front of , or behind the pistons in tdc Are the leads like the diagram .Thats why i sent the diagram of the location of ht leads. If you have spark and you have fuel then its should run..Unless its fireing in the wrong place.

szamik · #14 05-27-2017, 11:45 AM

Quote:

Originally Posted by optimusprime

Unless its fireing in the wrong place.

And this is the last thing I want to check but I don't know how

As I said before, strobe light into 1 cyl cable and while cranking spark is at OT mark so ignition at first cyl should be at right time - in my opinion. Is there any chance to check rest of plugs in a similar way, I mean using strobe light ?

liquiddog · #15 05-27-2017, 11:21 PM

Checked the OVP fuses?