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  #16  
Old 12-14-2003, 12:55 PM
azhari
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Thumbs up Solved!!!

It was a shot fuel pressure regulator!

Used one was FAILING.

Swapped it out with another used one from the wrecker which turned out to be a TOTALLY FAILED unit!

Engine surged terribly and fuel was pulsing from the FPR thru' the vent hose to the valve cover breather in rhythm to the surging of the engine!

On my FAILING FPR, a VERY SLIGHT amount of fuel leaked but on the TOTALLY FAILED one, it was very obvious - it wasn't leaking fuel but it was venting fuel!

Cheers, y'all and thanks for your ideas.

I have posted my FPR findings in another thread and hope it helps others diagnose similar problems in their cars.
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  #17  
Old 12-22-2003, 05:48 AM
azhari
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Not again...

OMG!

Same symptoms are back again after 2 days of driving.

All the fuel pressure regulators installed so far have been from the wreckers on an exchange basis.

I hope it's not the fuel distributor which was already replaced.

I checked the FD by bleeding each line to the injectors (with the engine running) and all 4 lines had fuel.Also, each time I cracked open a line, the engine idled a little rougher.So obviously, the fuel distributor is firing on all 4 lines.

Took the FD out and found that none of the vents (on top where the lines to the fuel injectors are connected) were blocked.

In my previous FD diagnosed as faulty by a techie, one of the vents from the FD were blocked.

My only guess at this moment is the FPRs that I got from the wreckers (btw they're all dirty) are already faulty (1 was venting fuel) or going bad (1 lasted 2 days).

Summary of FPRs used :

1 was venting fuel.
1 made the car run ok (after readjusting mixture) for 2 days before old symptoms came back.
1 did not solve the problem; neither was it venting fuel.

My question is could a fuel pressure regulator be faulty and not vent fuel?Would this result in too high fuel pressure (which I think is the case here) and cause my symptoms - black smoke, bad fuel mpg, a slight adjustment in mixture either way results in too lean or too rich (due to stuck high system fuel pressure?).

I have seen a confirmed case of a faulty FPR coz it was spitting fuel out of the vent hose with the engine running.

Does a stuck diaphragm mean that the FPR is faulty but does not vent fuel?After all, if the diaphragm is stuck, how can it push the fuel out of the vent hose (this is my reasoning)?

As always, all techies are screaming "fuel distributor" wihtout even wanting to diagnose further.

I would think that FDs go a long way.Also, having seen my previous FD with one vent blocked and the "new" used one after cracking the lines open with the engine running, I would deduce that the "new" used one is OK.

Or am I wrong?

I would assume that if I had a bad FD, swapping out the FPR would make no difference to the problem and yet, I had managed to get the car running for 2 days earlier before the symptoms came back again.

On one hand, I think that it's not likely that all the FPRs that I have used are faulty, but they're all from the wreckers so I'm unsure.

When I swapped the old FD out, I also swapped out my FPR with a used one from the same wreckers at the advice of one of my tech friends even though we did not test it.It was not venting fuel but had a little fuel in the side where the vent hose is attached to.The FD/FPR swap was done 2 months ago.

Fuel pump, fuel filter and accumulator checked out ok but none of the symptoms point to these stuff anyway.

Sensors have been checked and tested as per MB CD specs, running the car with the EHA disconnected so the electrics are eliminated from the equation anyway.

I hope anyone out there has more specific info (I thought I had) on fuel pressure regulators and how they specifically fail.

Thanks in advance.
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  #18  
Old 12-22-2003, 05:59 AM
azhari
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Another symptom is severe hesitation on acceleration.

Air flow plate will flutter when accelerating from stop.Car will crawl and black smoke will spew.

After leaning the mixture, hesitation is not so bad but still smoking (tooo rich even when set lean).

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  #19  
Old 12-22-2003, 06:20 AM
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Join Date: Apr 2003
Posts: 345
If a Fuel pr. reg changes things, buy a NEW one /
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  #20  
Old 12-26-2003, 12:45 PM
azhari
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A spanking new BOSCH fuel pressure regulator is in, re-tuned mixture...and of course...STILL THE SAME SYMPTOMS!!!

A new FD again?Aw, c'mon..you gotta be kidding me...

And I thought I was soooo close....

Damn!
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  #21  
Old 12-26-2003, 10:14 PM
azhari
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I wonder how the car could run well for 2 days with another used fuel pressure regulator when I had the problem again?

Now with a brand new FPR, I can't get it to run well.

I took out the rotary idle valve and cleaned it with carb cleaner.With the engine running if I pull off the connector, idle goes up and when I re-connect it, there is a click and idle goes back down.So it's working.

Took off the FD and look between it and the AFM.O-ring seal is good and no leaks.

Cracked lines going to injectors at fuel distributor head and could bleed clean fuel from all 4 lines with the engine running.

Looked at fuel pump/fuel filter/accumulator and found no leaks.

Fuel pump/fuel filter/accumulator look very new.

Fuel pump was not making any unusual noises.
No hardstarts whne warm so accumulator is working.
Took off fuel filter and only clean fuel came out, besides never had any hesitation at high speeds so the filter is good.

Took out and cleaned 4-pin coolant temp sensor.Tested when cold abt 3k+ ohms and abt 280 ohms at abt 85 deg C so it's ok.

Currently driving with the EHA off anyway so no cold starts (cold start valve is ok and not leaking).But this eliminates the electrics from the problem.

Definitely a mechanical problem.

If the "new" used FD is bad, I wonder how it could go bad after just 2 months?

Another concern I have is that assuming in this case that the FD has gone bad and I swap it out again, it may go bad again in a couple of months?Is something causing my FDs to go bad?Or am I just unlucky?

Or could the problem not be the FDs and be something else that I have missed?

Ignition stuff are fairly new (less than a year) but they wouldn't cause the car to run rich.

Anything else in the fuel system I should check that I have missed?

I checked the entire length of the exhaust but did not see any O2 sensor (but I have pin 3 on X11!!!).Even if I did, and it was faulty, the car still runs rich with the EHA off so this possibility is eliminated as well.

Could a faulty EZL controller contribute to rich running with the EHA off?ECU?

Any ideas?

Thanks in advance guys.
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  #22  
Old 12-26-2003, 10:18 PM
azhari
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Should I give it a shot of injector cleaner (though I'm quite skeptical it will work)?
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  #23  
Old 12-26-2003, 10:21 PM
azhari
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More checks...

Fuel pump relay is not overheated.

OVP (updated version with 2 x 10A fuses) fuses are good.

Anyway, these were both renewed less than a year ago and solved a stalling problem.

The car does not have a stalling problem at this moment.

What else...
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  #24  
Old 12-28-2003, 09:16 PM
azhari
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Did I miss anything?
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  #25  
Old 12-29-2003, 01:18 PM
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Join Date: Aug 2002
Location: Central Asia
Posts: 104
I suggest that you should check the FD for leaks in the bottom to the airflow housing. Push the air meter plate and see if the inner wall is moist and if there is any fuel inside the housing .

In my opinion the FD leaks because there is excessive pressure in the fuel line. It happens when there is dirt and water in it. To stop the FD from leaking I do the following:

1 Tap on the fuel pressure regulator and restart the car. If the problem persists add an injector cleaner and drive some 300-400 kms.

2 Remove the injectors and using the medical injector (with no needle) force some injector cleaner into the injector (picture). This will clean it from dirt and you will see how the spray pattern improves. Use rubber gloves and take caution because liquid is flammable and bad to inhale.

3. To clean the injectors from water use the tire inflators pressure to let high pressure air through the injector. In my case there was lots of water in injectors.

Doing the steps above stops my cars FD from leaking.
Attached Thumbnails
190E running rich problem AGAIN after repair!!!HELP!!!-injector.jpg  
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2002 Daewoo Nexia 50.000 km
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  #26  
Old 12-29-2003, 09:49 PM
azhari
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Good info!

I had taken the FD out last week to check for a leak but it was not leaking in the bottom if I remember correctly.

Took the AF plate off and checked the inner wall but it was just a little moist.

O-ring between FD and AFM also in good condition.

Excessive pressure seems to be the problem, which urged me to put in a brand new FPReg to remove it from the equation.

But now, the car still performs the same.

Quote:
because there is excessive pressure in the fuel line. It happens when there is dirt and water in it
Did you mean that there could be dirt and water in the FD?

So it seems that from the steps you have described, we are actually driving the dirt/water from the FD out thru' the injectors.

I have bled the FD at the lines on top of it going to the injectors (with the engine running).Bleeding each line resulted in clean fuel leaking from it and caused the engine to idle a little rougher.The results were equal across all 4 lines.

So the FD is firing on all 4 injectors but something is crapping out it's ability to perform properly.

How was your car running before you went thru' the steps described in your post?

Tks, dude.
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  #27  
Old 12-30-2003, 12:29 AM
Registered User
 
Join Date: Aug 2002
Location: Central Asia
Posts: 104
I meant that there could be dirt and water in injectors. If you clean the injectors the FD will experience less pressure and it might stop leaking.
__________________
1989 230E, 8v, 166.000 km, updated to 94/95 trunk & hood
2002 Daewoo Nexia 50.000 km
Sold:
1987 VW Jetta GLE 16V, Recaro seats
1982 Volvo 240 DL (lovely car!)
and few more american cars.
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  #28  
Old 12-30-2003, 12:58 AM
azhari
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Did you have the same problems (running rich, black smoke, hesitation,etc) prior to cleaning the injectors?
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  #29  
Old 12-30-2003, 01:23 AM
87-300E_in_NC's Avatar
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Location: outside of Raleigh, NC
Posts: 203
Question Hi azhari

Hi azhari,

Did you happen to check the fuel return line (and if your car has a valve at the tank, may want to make sure it's ok and air blows freely one direction, (back into the tank from regukator).

I also have not ruled this line out to be an issue with my 300E / 2.6. When I first removed the fuel return line and tried to blow through it, I almost could not, as it was very difficult. I removed the gas cap (which is pressurized) and some pressure escaped, but when I repeated the test with the gas tank removed for cleaning, it was the same, difficult to blow through. So, I replaced the fuel valve at the tank, and it seemed to make a difference as to blowing through the line, but I still have "too much fuel" that keeps flooding my engine....and yes, I have made many checks and have purchased many new parts along the way after a complete head rebuild.

My next test will be to bypass the fuel return line with a seperate line on the outside of the car. Fuel pressure regulator has been changed with used one off a good working engine, but no change.

Hope this helps, and I will let you know the resultsof my fuel return test.

Take care, and good luck.
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  #30  
Old 12-30-2003, 01:41 AM
azhari
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Quote:
Did you happen to check the fuel return line (and if your car has a valve at the tank, may want to make sure it's ok and air blows freely one direction, (back into the tank from regukator).
Yep.This seems like the only possibility left apart from a faulty FD.

So in order to check this, is it right that I take off the fuel return line from the back of the FPReg and blow into it (after depressurising the fuel system)?

Maybe the fuel is return to the tank at a certain pressure, which would explain why there's "resistance" when you blow into it even after changing the tank valve.Just a thought.

Anyway, it's coll that you're testing the fuel return line coz I'm dying to know of your results.

Let me know.

Thanks and good luck to you, too.
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