Cranks but wont start
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Junior Member
Joined: Sep 2017
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AMG E63s
Cranks but wont start
1989 190E 2.6
My son & I need some diagnostic help.
We just bought the car as a project. It will crank, but wont start.... unless we use starting fluid. It wont idle though and dies.
We have new oil/etc, a new battery, new fuel filter & fuel pump relay & new spark plugs.
We tested the fuel pressure, it reads at 80psi & 5.5-6. The fuel injectors appear to be sauirting fuel. The cold start injector squirts out gas as well. We can hear the buzz of the fuel pump.
*** OH yeah, When we put a different fuel distributor on, thats when fuel started squirting, not before.*** We also drained the gas tank & filled it with 1/4 tank of 91. We checked as many vacuum lines as we could, they all appear to be connected. This last time we started it w/starter fluid & ran it for about a min, it did kick out a lot of white smoke from the exhaust.
what are we missing?
My son & I need some diagnostic help.
We just bought the car as a project. It will crank, but wont start.... unless we use starting fluid. It wont idle though and dies.
We have new oil/etc, a new battery, new fuel filter & fuel pump relay & new spark plugs.
We tested the fuel pressure, it reads at 80psi & 5.5-6. The fuel injectors appear to be sauirting fuel. The cold start injector squirts out gas as well. We can hear the buzz of the fuel pump.
*** OH yeah, When we put a different fuel distributor on, thats when fuel started squirting, not before.*** We also drained the gas tank & filled it with 1/4 tank of 91. We checked as many vacuum lines as we could, they all appear to be connected. This last time we started it w/starter fluid & ran it for about a min, it did kick out a lot of white smoke from the exhaust.
what are we missing?
MBWorld Fanatic!
Joined: Mar 2016
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From: SF Bay Area, CA
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Have you checked the engine mechanical basics for compression or/an ran a leak-down test?
Have you checked to make sure the timing is correct by aligning the cam marker and also checking the flywheel marker as seen from the bottom of the engine (the 0, 120, 240 degree marker)
After those check out since you can run it and measure the EHA current when cold and make sure the ECU is outputting the correct EHA current. 20mA with ignition on engine off. As you crank it it will jump high to like >60mA.
And when it starts, there is table/graph that shows the EHA current at various Engine temps. At room temp it will be in the 10mA-20mA range from what I remember. It is considerably higher for cold temps like 0c. Maybe >30mA. And at running temp (85c) it is back down to near zero and goes to closed loop and regulating. But check the table to make sure.
Good luck with the project!
Have you checked to make sure the timing is correct by aligning the cam marker and also checking the flywheel marker as seen from the bottom of the engine (the 0, 120, 240 degree marker)
After those check out since you can run it and measure the EHA current when cold and make sure the ECU is outputting the correct EHA current. 20mA with ignition on engine off. As you crank it it will jump high to like >60mA.
And when it starts, there is table/graph that shows the EHA current at various Engine temps. At room temp it will be in the 10mA-20mA range from what I remember. It is considerably higher for cold temps like 0c. Maybe >30mA. And at running temp (85c) it is back down to near zero and goes to closed loop and regulating. But check the table to make sure.
Good luck with the project!
MBWorld Fanatic!
Joined: Feb 2020
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Likes: 394
1991 190E 2.3
You want to make sure you're only using premium gas. W201s run on premium gas only as noted on the gas tank door opening and in the owners manual. You should also have more than 1/4 of a tank of gas. That low amount of gas in the tank can put a strain on the fuel system. I don't see that you've changed out the spark plug wiring. That likely also needs to be replaced. Have you tested the alternator to make sure it's working properly? Sounds like the previous fuel distributor was part of the problem since the car does a little better with the different distributor. Have you looked at all of the engine wiring to make sure that no wires are frayed and that all of the wiring connections are clean and tight? Have you made sure that the fuel lines aren't clogged in some way that would prevent gas getting from the fuel tank to the engine? I would suggest making sure that you do all of these easy things first. Once you've been through this list of easy checks, then it'll be time to look further as to what might be the problem. Let us know if these easy checks help at all. My W201 is the 2.3 so it's a little different than the 2.6. Hopefully Dolucassi who owns a 2.6 will be along soon to also help with the diagnosis.
Member
Joined: Dec 2016
Posts: 129
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From: Pittsburgh Pa. - Mebourne, Florida
1993 190E Sportline; 1992 190E 2.3
Is the engine creating enough vacuum to pull the AFM plate down to energize the fuel injectors? You could have knocked off a big vacuum hose under the AFM.
Did you reset the position of the Fuel distributor in relation to the AFM? There is a precise relationship between the Fuel distributor piston and the AFM plate.There should be 1-2mm free play of the AFM plate before it mores the FD piston. ( There should be an O ring between FD and AFM.)
I would try this - Push down slightly on the AFM plate while some one tries starting the car. BE CAREFUL -- WORKING AROUND FUEL IS DANGEROUS!! There should be a slight resistance when pushing down on the plate as well as high pitch whine that would indicate the injectors are injecting.
On another front- Did you check for a strong spark while cranking?
Did you reset the position of the Fuel distributor in relation to the AFM? There is a precise relationship between the Fuel distributor piston and the AFM plate.There should be 1-2mm free play of the AFM plate before it mores the FD piston. ( There should be an O ring between FD and AFM.)
I would try this - Push down slightly on the AFM plate while some one tries starting the car. BE CAREFUL -- WORKING AROUND FUEL IS DANGEROUS!! There should be a slight resistance when pushing down on the plate as well as high pitch whine that would indicate the injectors are injecting.
On another front- Did you check for a strong spark while cranking?
