1986 190E isn't gettin fuel from distribution - PeachParts Mercedes-Benz Forum

2020pup · #1 04-28-2009, 10:45 PM

Sorry if this has been answered already but I couldn't find it. I bought a 190E at a yard sale. Yes, a yard sell for 200 bucks. Body is in excellent shape along with the interior. The guy said the Fuel pump relay was bad. Well, the relay is good. It was the pump that was bad. I installed the pump with the excitement of rollin in my MB but it won't start. If you spray a little fuel in the air intake it fires right up but quickly dies from stravation. I've replaced the fuel pump, fuel filter, spark plugs, wires, cap and button and i drained and flushed the gas tank. I have good fuel pressure coming in to the fuel distribution and out. I have fuel pressure at the cold start valve. But no fuel will come out of the four lines from the distribution. So I decided to break open the fuel distribution (cause there was a extra one in the truck) to maybe see what was going on inside. It was clean but the o-rings around the pump inside it were trash. I replaced them and clean everything really good. Put it back on and still no fuel will come. As i dug around under the seats I found 3 electromagnetic pressure actuators there. So It seems the guy was thinking the same as me, "it's not gettin fuel". But why? What am i missing here? Think it's a vaccum problem? Or does that system need to be primed? I thought I could talk to the local MB dealer, but well he was a real SOB

and wouldn't tell me anything other than just bring it in. So please, if you have any suggestion let me hear them. Thanks in advace

mbdoc · #2 04-29-2009, 08:09 AM

Getting fuel to the fuel distributor doesn't count on that car!

You MUST have 85psi of fuel pressure, takes 60psi to 'push" the injectors open.

Connecting a gauge to the cold start injector would be the first step.

sranjesuper · #3 04-29-2009, 03:09 PM

I had the same problem last year on my 2.6 when i did the headgasket and replaced everything that needed to be replaced. After everything was assembled, it cranked but wouldn't fire. I unplugged the line going into the injectors and there was no fuel going into the injector but there was fuel going into the distributor. Somehow i just decided to push down on the fuel metering plate while somebody cranks it, and then it sputtered to life. I guess i was reallly lucky and that could have been much harder and probably is for most people.

2020pup · #4 04-29-2009, 10:10 PM

Thanks for the ideas. And holy s#@%. are you serious on the fuel pressure!!!!!!! Think i'll backtrack the fuel line and see if any leaks and put a fuel pressure guage on it. I got the pump from a junk yard. But have a new too I'll try the new one tommorrow if it doesn't rain me out. Going to also trying pushing down on the FMP before i swap pumps. Any other ideas let me know. I'll keep you guys posted and thank you for suggestion

Ivanerrol · #5 04-29-2009, 10:23 PM

M.B.Doc is very serious about the fuel pressure.

Fuel pumps are one of those things that you can't skimp on. - Buy new.

The pumps rely on fuel going through them to be lubricated. A used example that has sat in a wreck or on a shelf for a long time maybe be suss.

tinypanzer · #6 04-29-2009, 11:25 PM

Do try pushing on the air meter plate. If the car has sat for a while with no fuel going through it, it could be stuck.

You should notice that when you push on it with proper fuel pressure, it will be much harder to push than when you have no fuel pressure.

With the ignition (but not the engine) ON, if you push the air meter plate, it should cause the injectors to squirt. The gas would then run down inside the bottom of the intake manifold just under the butterfly since the engine isn't running and sucking it into the cylinders. I've never worked on an M102, but I am assuming the setup is similar to M103.

Try using a mechanic's stethoscope on the injectors. When you push the air meter plate with ignition ON, you should hear them squirt.

mbdoc · #7 05-05-2009, 08:03 AM

Since the car now has enough fuel pressure to almost run, try adjusting the lamda tower screw a 1/4 turn in either direction. Make a mental note of the direction & see if you can then keep the engine running. If worse go the other direction. You shouldn't have to adjust more than 1 complete turn in either direction.

You will need a long 3mm allen wrench. Push the allen down & then turn.

2020pup · #8 05-05-2009, 10:37 PM

Ummm MB doc, think i'll need you to draw me a picture on that. I have no idea of what that is..or where that might be.

slk230red · #9 05-05-2009, 10:41 PM

Quote:

Originally Posted by 2020pup

Ummm MB doc, think i'll need you to draw me a picture on that. I have no idea of what that is..or where that might be.

If your tower is still sealed from the factory, it will have a ball bearing in the top.

tinypanzer · #10 05-05-2009, 11:34 PM

While you're in there, check the idle air hoses previously mentioned in this thread. (see the yellow arrow). These hoses get hard and brittle and stop sealing around the ends. There is another idle air hose coming out the other side of the idle air valve, but you can't see it in this picture. They caused me tons of grief.

Also, you can easily test your idle air valve from here. Pull off the wire (blue arrow) and put a 9v battery to the terminals. You should hear it clunk.

M.B. Doc is an expert (I'm not), so heed his advice!!

2020pup · #11 05-06-2009, 06:38 PM

ok for todays update...I did what MB doc (thanks for the pic)said and there was no change in the car. It's still doing the same. It will almost start but won't run. Put a little gas down the air valve and it fires right up then quickly dies. Every now and again can really pump the throttle and it will stumble around for about 3 mins and die. Check fuel pressure and it is the same as before. 80 psi. I also did what tinypanzer suggested (thanks for the pics too). Took 9 volt battery to idle control valve terminals and got no sound, no nothing. Checked the hoses too and they are ok even the one that runs under intake (used a mirror). So whatcha guys think now?

Ivanerrol · #12 05-10-2009, 04:36 AM

The injectors have a set pressure before they will start spraying. You maybe now getting fuel out of the top of the FD but is the pressure enough to operate the injectors?
How is your fuel pressure regulator? Have you changed that yet?
The EHA only regulates enough pressure between the upper and lower chamber of the FD to cause some enriching or less rich mixture during engine operation. Its operation is regulated by the ECU which in turn gets info from the heat sensors and O2 sensor to regulate the richness of the fuel mixture. If the OVP is blown the EHA has no effect. The injection system will work just fine - without regulation.

2020pup · #13 05-10-2009, 12:15 PM

No Ivanerrol, haven't replaced the regulator yet. But that makes pretty good sense. I was just thinking that the injectors maybe be gummed because everything else has been. Is there anyway to check the regulator? The OVP is working proper. I checked it a couple of days ago, SLK230red walked me throught that.

slk230red · #14 05-10-2009, 02:04 PM

Quote:

Originally Posted by 2020pup

No Ivanerrol, haven't replaced the regulator yet. But that makes pretty good sense. I was just thinking that the injectors maybe be gummed because everything else has been. Is there anyway to check the regulator? The OVP is working proper. I checked it a couple of days ago, SLK230red walked me throught that.

I haven't seen any threads that indicate a fuel regulator fixes a no fuel at injector problem, but you would think it would happen at some point.

Also, since you purchased the car with a 'no fuel at injectors problem', and you seem to be making progress, you might want to try pinching off or blocking the Fuel Accumulator hose that goes to the gas tank. At least this will ensure that you are getting all of the fuel and pressure to the Fuel Distributor.

Fuel delivery test from my manual:

Specification:

1 liter in maximum 40 seconds at a minimum
voltage of 11.5 volts at the fuel pump.

If the delivery is less than 1 liter in 40
seconds, test the following points:

a) Test voltage at the fuel pump. Specification
at least 11.5 volts.

b) Check that strainer in supply line fitting of
fuel distributor is not blocked.

c) Check fuel lines for restriction points
(pinched lines).

d) Clamp off leak line between fuel accumulator
and fuel suction hose. Re-check fuel
delivery. If the specified delivery quantity is
reached, replace fuel accumulator.

e) Replace fuel filter.

Just a thought....keep reporting back Brent. Curious minds want to know.

Dave

pentoman · #15 05-10-2009, 04:19 PM

I would be sure that the fuel pump is continuing to run when it starts. It gets a signal from a crank sensor. Without this signal I believe it starts and then quickly dies. Or even better as suggested rule out the fuel pump by removing fuel pump relay and bridging the neccesary terminals.
Am I right to think you can increase the pressure to the injectors by pushing down the flap in the air intake? So if someone will turn the key for you, you may be able to use this method to keep the motor running, instead of pouring fuel in the intake. It may be possible to rule out clogged injectors etc this way or at least get a better idea how things are going?

Oh in case you didn't know how this Jetronic system works - interesting:
http://www.youtube.com/watch?v=WFhJLLCjKdQ
that's so cool!

good luck