190e Won't Start . . .. - PeachParts Mercedes-Benz Forum

Boinftw · #1 11-29-2005, 03:45 PM

1987 190E 2.3 8v

It'll turn over just fine, and try to start, but the only fuel going into the intake seems to be from the cold start valve. I am getting no fuel from the four outlet on top of the fuel distributor. I speculate it's a problem with the EHA valve. Am I understanding right that a bad OVP will/can directly affect the EHA? Could the EHA be plugged up internally?? Should I be able to get some flow through it always?

FWIW, the ICV doesn't seem to do much -- it's always in the same position. Should it open or close when starting, or only if the car is running?

Thanks!!

mctwin2kman · #2 11-29-2005, 04:30 PM

First if the AFM plate is not sucked down you will not get any fuel from the injectors. Turn the ignition on and press the plate down and see if you get fuel. If the EHA is bad you still will get fuel flow. Just not adjusted the same. The EHA adjusts the pressure diferential between the lower and upper half of the fuel distributor. The fuel injection is Mechanical with some Electronic Control. So if the Electronic Control side fails the Mechanical still will work. If you get fuel flow with the AFM plate pushed down I would then check the AFM to Throttle Body Rubber Boot for cracks causing an air leak thus bypassing the AFM Plate and thus no fuel out the distributor. The AFM plate is what meters and allows fuel flow. As you push it down more fuel is allowed to flow.

Boinftw · #3 11-30-2005, 09:12 AM

Thank you very much for the reply. About the time I thought I had a small grasp on how it worked, it slipped through my hands!

mctwin2kman · #4 11-30-2005, 09:20 AM

No problem. Let us know if you get some fuel by pushing down the AFM a hair. If you have an extra person to turn the key and crank for you and you slightly push the AFM plate down and she starts then at least you are getting closer to the issue. On the 190Rev forum there is a whole 15+ page thread about the AFM and adjustment. That is where we found the cracked boot that can be an issue. On cold days the rubber is stiff before startup so it will leak much more if it is cracked. Then it will warm up and become more plyable and thus the car will run. Not well but it will run. I noticed my boot was cracking when I did my head gasket. Not to bad to replace if that is it. 20 bucks for the part and an hour to an two hours depending on ability to replace it. You basically remove the Top Part of the AFM that holds the fuel distributor as an assembly. It is three bolts and disconnect the fuel lines at the injectors and walla it is off. Well you need to unscrew the strap that holds the AFM Boot to the Throttle Body. Then with the AFM off you remove the 12-14 bolts and reverse and you are all set. If it is the problem I would take the time to thouroughly clean everything while apart. I hope that is the problem but if not let us know and we will go further.....

Boinftw · #5 12-01-2005, 05:26 PM

With the ignition on, I know I'm getting pressure to the cold start valve. I crack open the connections to the other four injectors and press the plate on the AFM slowly, all the way down. I get nothing out of the four on top of the distributor or at the top of the injectors. Please, don't let it be the distributor!

Any other possible causes?

Dave Horvath · #6 12-01-2005, 06:58 PM

I had a vacuum hose pop off on the under side of the intake on my 91 2.3. This hose was a hard one to get at, you need a small hand.

mctwin2kman · #7 12-02-2005, 08:56 AM

OK. Make sure you are getting enough fuel to the fuel pressure regulator. Just cause the cold start valve fires and squirts gas does not mean there is enough fuel flow. Since it is only one injector and does not flow continuosly. You may have a clogged fule filter or a bad fuel pressure regulator. Did you try to start it while someone pushed the AFM plate down a hair? Are you sure there is no fuel flow when you press the AFM down. I would do that while someone is cranking. If I recall the fuel pump does not stay on if the engine is not running. I think it only operates to prime when the key is on and then to run when the starter is engaged and then of course when she fires and is running. But I am not sure.... As mentioned as well check the rubber lines that comprise the IACV part of the system. IF they pop off or are badly cracked then the engine will not run. There are four of them. One from the bottom of the AFM assembly to the bottom of the IACV, one from the top of the IACV to the Idle Air Assembly(near the Cold Start Valve), one from the Idle Air Assembly to a plastic Check Valve looking thing, then the one from that to the bottom of the air cleaner(the one that connects to the valve cover as well). They can and will crack and can even slide off..... When this happens it creates a massive air leak causing the engine to no longer run...

Boinftw · #8 12-02-2005, 07:22 PM

Thanks for all the replys -- I did go through all my vacuum lines and did find some that were not correct. Plugged them in, and it fires right up.

However, now the idle is way too high, like 1800 rpm or so, and when I shift into gear, it drops way down, 500-600 maybe. I have to really stomp on the brakes, or it'll just take off when in gear.

I'm thinking a leak between the brake servo and the intake manifold? Too much air in, and no vacuum assist perhaps?

mctwin2kman · #9 12-03-2005, 12:21 PM

Now you may want to clean the IACV. Maybe it is sticking.. I would also spray liberal amounts of carb cleaner into the AFM and clean that as well. An oil and grime free intake is a happy intake.....

Also any air leaks will cause a higher idle....

Boinftw · #10 12-03-2005, 04:24 PM

IACV is new (supposedly that was the problem when I got the car.) I wouldn't be surprised if the AFM could use some work though.

Am I understanding that the OVP controls the IACV? Fuse is good, but the relay internally could have troubles.

Separately, there is a vacuum line that runs from the intake to the auto trans. Where does it connect on the tranny??

mctwin2kman · #11 12-05-2005, 10:37 AM

Modulator is on the drivers side of the tranny. Hard to see and even harder to get to if you have big hands.

The OVP controls power to various components. When pulled or bad the EHA will not function properly and the IACV and Cold Start Valve will not work either. The system will default to mechanical limp in mode. It will run a hair rich when this happens.