No fuel out of the fuel distributor 420 seil - PeachParts Mercedes-Benz Forum

satkhalsa · #1 05-17-2003, 05:19 PM

Hi all
420 sel 1986. Stalled on highway. never started again.

I changed the spark plugs, wires, cap, and rotor, and starter. fuel filter so far. I had few spark plugs wet now non are getting wet. No fuel shooting out or fuel distributor, fuel is going into the fuel distributor.

The idle control valve makes noise when ignition switch is on when I take the ovp relay off the noise stops.

Satkhalsa

stevebfl · #2 05-17-2003, 06:40 PM

You are not even close to any info that could be used to help with a diagnosis.

You ask the question as if you were going to figure this out. What you are really doing is throwing parts at it. The first thing you need to do is figure out whats missing. Do you know what is needed? This is the thought process you need to develope if you really wish to get a handle on this.

You need ignition, fuel, compression and timing. Fuel is easy. Take the air cleaner off and spray some starter fluid in the airhorn. Keep your face out of the way in case timing is your problem (a back fire will blow it right back at you). Too much fuel is also a possibility so be sure your plugs are dry to start. If fuel is the problem a little strter fluid should make the car at least act like it wants to start. With nothing else wrong the car will usually burst on with the fluid and die quickly.

The quality of ignition and fuel can be a problem so various forms of testing is necessary. Work on the fuel issue as it is the one you brought up.

satkhalsa · #3 05-17-2003, 08:07 PM

My wife was driving on the highway all of a sudden the car cut off and we had to tow it home. Checked spark it was weak. Checked spark from the coil very strong.

spark on cap very weak coming from coil. Checked for fuel,
pump running
fuel upto fuel distributor , at that time fuel was also leaving from fuel distributor.

checked 3 spark plugs they were getting wet.
spark on plug looked very weak.

while checking for spark burned out the starter motor from cranking too many times.

At this point decided to change plugs, wires, rotor, and cap.

replaced starter motor, plugs , wires , cap and rotor. Still no start.

regaped the plugs from .035 to .033 and at the same time discoverd there was no fuel on the plugs on left 4 plugs and only two plugs on the right side were wet.

opened 4 out 8 lines coming out of the fuel distributor no fuel comes out while cranking although few days ago it did when I initially checked for spark.

fuel is going in the fuel distributor and coming out of one line that i think is going to cold start valve.

I was also checking the fuel pump relay by jumping it. Fuel pump stayed on and still no start but after this idle control valve does not shut off or rather it is making this humming sound while the ignition key is on and cuts off only when i take the opv relay out.

Should I take the fuel distributor out to see if its blocked?
What can I do next?
please help

Satkhalsa

stevebfl · #4 05-17-2003, 10:52 PM

You should listen.

Its hard for me to come up with a test that requires no skill and no tools and yet I have done this here. You surmise that you have a fuel problem. If you are right a little fuel or starter fluid down the throttle proves it.

If you were right that far then you need to check fuel pressure next. If running some fuel or starter fluid doesn't change things then you have saved a bunch of money and time. It isn't fuel related.

IF its not fuel, testing the ignition without tools will be a little harder.

satkhalsa · #5 05-17-2003, 11:17 PM

Ok , I will start listening.

I just put some fuel down the air intake still no start.

Took the fuel distributor off and cleaned the bottom piece, dont know what its called but it was kind of stuck. Sprayed some dw40 and moved it in and out it was moving well the spring inside was also ok. This piece I think controls the air intake flap.

Put the fuel distributor back and turned the key without connecting the 8 fuel lines to the injector on top of the fuel distributor. Still no fuel coming out of them.

Removed the OVP relay and cranked at this point it wanted to start and fuel also came out of all the 8 fuel lines that I did not close on top of the fuel distributor. Also when I disconnect the OVP relay continuous humming of idle control valve also stops.

I thought know it would start so I reconnected the lines on top of the fuel distributor, still no start.

Why is the idle control valve start to make noise as soon as the ignition key is turned? did I do something to make that happen?

Please advise...

Satkhalsa

stevebfl · #6 05-18-2003, 10:44 AM

OK, we are going to try this listening thing one more time.

You put fuel into the motor and got no response. What did that tell us? It told us that fixing fuel won't fix our problem. you need to understand the thought process here.

You may have a fuel problem and if you keep working on it you will probably cause one. The point is if you you throw away the fuel pump and fuel distributer and place a little gas in the intake the car will try and run. If this isn't happening then your fuel problems can wait.

Find the reason why the motor won't work with fuel down the throat FIRST. Do you have compression?

>

The idle valve is powered when the key is on. Whether you can hear it or not doesn't matter to the problem at hand. It controls air intake at idle. It's function is easily by-passed by pressing the throttle. Tools help with diagnosis but there is absolutely no diagnosis without concept. If one thinks airflow into the motor is a problem, then the easiest diagnosis is to use ones brain to by-pass the concept. In the case of idle control openning the throttle makes short work of the concept (lack of air due to an idle air controlis keeping the engine from starting).

It is sometimes amazing the inter-relations and I can dream of senarios that would make my comments here really look stupid. Take for example: I am giving you a mechanism for evaluating the most basic need. Does the motor respond to manual application of fuel. I made it very simple because I see that knowledge of the systems are lacking. I took it upon myself to guess that you do not have an over fueling condition. it sounds like the system isn't getting any fuel by your own diagnosis. I gave a simple EXACT test. If you are wrong and thereis a way that fuel is pouring into the motor my test won't work. One senario would be a bad diaphram in the fuel pressure regulator. Another could be a leaking cold start injector. Both rather rare occurances, but that is what its all about; eliminating possibilities.

If you eliminate fuel, you have narrowed the possibilities significantly. We are not looking for a quantitative judgement on fuel, we are not looking at whether it does lambda control. The car don't start and it probably will do just fine when the one problem goes away.

Maddog · #7 05-18-2003, 11:13 AM

Geez...heated discussion

When you put "fuel in the intake" did you actually use starter fluid? You cannot just put gas in the intake you need the starter fluid. When using starter fluid, push the air meter arm down. Have someone sit in the car and crank the car and work the gas petal by pushing down a bit and releasing it. While the car is cranking, you spray short bursts of starter fluid in the car. Again, stevebfl is right, keep your face away incase the timing is off, unless you want a face covered in starter fluid

Follow those steps exactly and then you will find out if it is a fuel problem.

I just want to make sure, you are positive that there is fuel in the car? I don't mean to make you sound stupid, but it is an easy mistake to make.

If the starter fluid doesn't work, but your still convinced your not getting gas, then remove the supply line off of the side of the fuel distributor. put it in a bucket or a jar so that there is something to catch the fuel. Crank the engine and look and see if there is any fuel coming out. If there isn't any, you have a bad fuel pump relay or fuel pump.

To check the relay, connect all the stuff above back together. Crawl under the back of the car to the fuel pump. Remove the wires to the fuel pump and hook them up to a voltmeter. Crank the engine and see if there is a signal on the voltmeter. If there is no signal, then your relay is bad. If there is a signal and you hook the fuel pump back up and crank the car and it doesn't make any noise, or vibrate when you put your hand on it, then the fuel pump is bad....

Thats a start. Goodluck!

satkhalsa · #8 05-18-2003, 11:46 AM

No Maddog I did not use starter fluid. I will try with starter fluid to see if I get it to start.

The fuel pump is running, I am getting gas up to the fuel distributor.

I will do the tests both you and Steve mentioned and will post the results.

Thanks guys, appreciate all the help and bear with me I am new to all this.

satkhalsa · #9 05-18-2003, 12:40 PM

Put fuel in the throat and cranked but still no start.

I checked for spark by pulling the wire and holding it close to the valve cover and saw a very weak and intermittent spark. Did this on two wires. looks like spark may be the culprit.

but I just changed the rotor, cap, wires, and spark plugs.

whats next ? Please advise...

satkhalsa · #10 05-18-2003, 12:50 PM

Oh yes, when I put the fuel in the air intake I was also holding the air flap down and cranking to eliminate the possibilty of air not going in..
forgot to mention that in previous report.

stevebfl · #11 05-18-2003, 01:10 PM

It gets harder to plan conclusive tests without dedicated tools on the ignition. A coil is a possibity, but control is also an issue.

A semi critical test can be done by breaking the electrode off a spark plug and attaching it to the coil wire first and then a plug wire. The plug should be laid on the valve cover and the spark should make it to either the threads of the plug or the valve cover; jumping at least a quarter inch gap. At the coil it should be rapid and consistant. At theplug it will obviously happen only an eight as much.

Maddog makes a good point about the starter fluid except that most engines that are otherwise healthy will have no problem lighting off a little (I say little) fuel. The starter fluid is better as it is already atomized. Just its vapors will light right up (make sure that happens inside the motor - starter fluid is even more flammable than gasoline).

satkhalsa · #12 05-18-2003, 01:53 PM

Ok Steve,

Spark jumps at least 1/4 inch gap on both the coil wire and all the spark plugs.

Whats next?

satkhalsa · #13 05-18-2003, 01:56 PM

On the coil wire it was rapid and consistent and at the plug it was less frequent.

stevebfl · #14 05-18-2003, 02:29 PM

We may never get an answer with only qualitative questioning, but we still got one more of the basics. How is the compression?

Probably all you need to know here is whether or not you have jumped a chain. Which gets to timing issues. You might need to verify cam timing and at the same time verify the ignition timing. The kind of timing I am worried about is not an adjustment. I am concerned that the chain could have jumped. This would show up with a compression test.

satkhalsa · #15 05-18-2003, 02:47 PM

How can I test the compression? Or rather is there a way for me to test the compression or do I have to send the car to the shop?

Where do I go from here?