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AdrianD
10-27-2015, 07:25 AM
I'd like to preface this by saying that about one year ago I've done the following:
Replaced all fuel line o-rings (green ones from MB)
Fixed one injector with high leak-off
Replaced the fuel line from filter to low-pressure pump
Replaced fuel filter

Two years ago the previous owner changed the seals in the high-pressure pump
About a couple of months ago I've changed the seals on the injector return nipples.

What the car does is this: it starts perfectly, idles for a few seconds then dies. And it takes a very long crank to start back again. Then it will run normally and won't do it until it sits longer than 24 hrs. It only manifested like this three times ever, as it's used daily and doesn't usually stay off longer than 24 hrs.
One time, the next day after shutting off, after starting the idle dropped briefly about 200 rpm when idling, then everything was normal.
No error codes, no visible fuel leaks and no other symptoms (loss of power/cutting out)

I've read that the o-rings in the fuel pressure regulator might dry off and cause problems

Thanks in advance.

surlyoldbill
10-27-2015, 04:35 PM
Sounds like air in the fuel line. OM612 has clear fuel lines so you can see if there is air collected at the top, or when running there will be bubbles or foamy looking fuel. Search forum, but most air leaks are from the fuel filter. It requires some tweaking and skill to get it "just right" so there is no air intrusion. Common mistake is to tighten the water drain too much, which deforms the side of the filter and lets air in. Sometimes water sensor gets twisted on wrong.

NelsonSprinter
10-27-2015, 07:49 PM
Agreed, air leak from filter, try placing 15w40 oil on o-rings, or replace fuel filter with one without drain screw and water sensor as seen in my link below

If pressure regulator had bad Orings it would cause a shut down on higher acceleration, not a start-up

MercedesGenIn
10-27-2015, 11:05 PM
Hi there

Try replacing the 5 dollar black non return valve or its O ring on the fuel filter. What happens is it drains back the supply line, there is enough to start it then dies. further cranking to draw fuel.

Regards
Steve

AdrianD
10-28-2015, 06:57 AM
Sounds like air in the fuel line. OM612 has clear fuel lines so you can see if there is air collected at the top, or when running there will be bubbles or foamy looking fuel. Search forum, but most air leaks are from the fuel filter. It requires some tweaking and skill to get it "just right" so there is no air intrusion. Common mistake is to tighten the water drain too much, which deforms the side of the filter and lets air in. Sometimes water sensor gets twisted on wrong.

After all the work done last year, I could still see foaming in the line from the fuel filter to the low-pressure pump after starting but it never bothered me since it started well.
Yesterday when starting I saw bubbles then foaming in the return line from the pressure regulator to the high-pressure pump, maybe this gives a clue?

Agreed, air leak from filter, try placing 15w40 oil on o-rings, or replace fuel filter with one without drain screw and water sensor as seen in my link below

If pressure regulator had bad Orings it would cause a shut down on higher acceleration, not a start-up

Can you please like the simpler fuel filter? :)

Hi there

Try replacing the 5 dollar black non return valve or its O ring on the fuel filter. What happens is it drains back the supply line, there is enough to start it then dies. further cranking to draw fuel.

Regards
Steve

Going to the MB dealership today after work to pick up that valve.


Thank you everyone for the suggestions, I will keep this updated.

General question about the fuel line o-rings. If they leak air in, shouldn't they leak fuel out, too ?

Aqua Puttana
10-28-2015, 11:38 AM
Your engine mounted mechanical low pressure pump sucks the fuel up from the tank.

vic

MillionMileSprinter
10-28-2015, 03:29 PM
General question about the fuel line o-rings. If they leak air in, shouldn't they leak fuel out, too ?
To further explain what Vic just said, No.
On your engine, the low pressure pump is all the way up on the front of the engine and it SUCKS fuel all the way from the fuel tank, through the filter and up to the pump. It is constantly under vacuum, so fuel won't leak out, but rather air will leak in. It is a common problem with these engines, one that MB fixed in the '04 and up engines by placing a pusher pump in the tank and removing the sucker pump.
I have had great success with many '02 and '03 Sprinters with using a filter that has fewer holes in it, like Nelson Sprinter suggested. I don't even bother spending time trying to get the stock filter to stop leaking.
Also keep an eye out for the clear fuel lines to become cracked with age and the union where the black rubber fuel line from the tank connects to the filter can get old and brittle. Just trimming it back an inch or so helps.

surlyoldbill
10-28-2015, 03:55 PM
My first few fuel filter changes, I spent a LONG TIME getting the air intrusion to stop, revisiting it for a few days to adjust. I also discovered the Hastings filters are crap; they were out of tolerance just enough so that the o-rings didn't seal very well. I had to stack o-rings and use rubber washers as gaskets to make the Hastings stop leaking air. Mann filters work well. I have also gone the no sensor route, but have yet to install it.

AdrianD
10-28-2015, 04:30 PM
Your engine mounted mechanical low pressure pump sucks the fuel up from the tank.

vic

To further explain what Vic just said, No.
On your engine, the low pressure pump is all the way up on the front of the engine and it SUCKS fuel all the way from the fuel tank, through the filter and up to the pump. It is constantly under vacuum, so fuel won't leak out, but rather air will leak in. It is a common problem with these engines, one that MB fixed in the '04 and up engines by placing a pusher pump in the tank and removing the sucker pump.
I have had great success with many '02 and '03 Sprinters with using a filter that has fewer holes in it, like Nelson Sprinter suggested. I don't even bother spending time trying to get the stock filter to stop leaking.
Also keep an eye out for the clear fuel lines to become cracked with age and the union where the black rubber fuel line from the tank connects to the filter can get old and brittle. Just trimming it back an inch or so helps.

Got it, in that case, this sounds like it's going to be "fun". And would that explain why I see foaming in the filter to LP-pump line for a few minutes after starting?

My first few fuel filter changes, I spent a LONG TIME getting the air intrusion to stop, revisiting it for a few days to adjust. I also discovered the Hastings filters are crap; they were out of tolerance just enough so that the o-rings didn't seal very well. I had to stack o-rings and use rubber washers as gaskets to make the Hastings stop leaking air. Mann filters work well. I have also gone the no sensor route, but have yet to install it.

I'm using a Mann filter, just checked and I also have a non-return valve on the supply line, right before the filter.


I had to stay late at work today and the dealership closed so tomorrow is going to be the day I buy the valve on the filter.

AdrianD
10-29-2015, 08:55 PM
Bought a new return valve and installed it, will report back tomorrow.
In the meantime, first start of the day, I kept the revs a bit over idle and when I let off the accelerator, the engine stalled. After turning over for quite a bit it started and with galloping idle.

surlyoldbill
10-29-2015, 11:29 PM
If you get everything sealed right, you should see NO air in line before starting it. Another place is the fuel return lines where the connect to the injector. Be careful, they are plastic and tend to break if man-handled. The replacement line comes with metal fittings ($100+/-).

AdrianD
10-30-2015, 07:52 AM
Back with some info this morning:
All lines were full before starting. It started and then the line from low-pressure pump to high pressure pump started to foam and when I saw bubbles the engine stalled. So indeed it's catching air.
Time to buy a new fuel filter without the water sensor and the drain hole. The o-ring on the return valve fitting was also a bit hardened and the new valve from MB does not come with a new o-ring.

I will return with more info.

Regarding the return lines, I've replaced the o-rings on the nipples and I have new return hoses up to the fuel pressure regulator.

Edit: looking at Mahle filters, I have found 3 different part numbers:
KL 100/2 - Sprinter 901, without drain hole
KL 195 - Sprinter 901, with drain hole
KL 188 - Jeep, with drain hole and water sensor.

The Mann filter without drain hole is WK 842/13

AdrianD
10-30-2015, 10:12 AM
For anyone looking for the return fittings, I found them CHEAP and good quality in the UK, with worldwide delivery:

http://www.ebay.com/itm/281466773901?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Aqua Puttana
10-30-2015, 01:12 PM
A less expensive plastic option for USA. It is without the clips and hose though.

http://www.amazon.com/Mercedes-Sprinter-Injector-Connector-BG07035/dp/B00Y1HQAVG/ref=sr_1_fkmr0_2?s=automotive&ie=UTF8&qid=1443058893&sr=1-2-fkmr0&keywords=sprinter+injector+fitting

vic

surlyoldbill
10-30-2015, 04:43 PM
Adrian, it seems like you might have an issue between the fuel filter and the tank. Others have reported a loose or damaged pick-up tube in the tank, or cracked hose from tank to fuel filter. If there was no air in lines before start but air after engine was circulating fuel, it could be issues at the tank or possibly with the low or high pressure fuel pumps sucking in air when they are operating. It might require a scan with the correct scanner to diagnose.

Do the foam/bubbles eventually disappear, or are they constant? If they go away at some point, but there is no visible air before starting, there must be a big chunk of air SOMEWHERE that shows itself after circulating the fuel. An air leak between the high pressure pump and the return line coming back to the fuel filter might not show in the clear lines, and there wouldn't be a fuel leak because the fuel simply goes back to the tank as air gets in. The slight vacuum created by the fuel returning to the tank would prevent fuel from leaking out of the system, so a leak at the top of the system, at the injector return lines, wouldn't show much if a sign of leakage, but maybe a little. I'd inspect under the injector cover to see what's happening up there.

surlyoldbill
10-30-2015, 04:45 PM
For anyone looking for the return fittings, I found them CHEAP and good quality in the UK, with worldwide delivery:

http://www.ebay.com/itm/281466773901?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

wish I'd seen this before I bought the complete kit to replace ONE broken fitting...

AdrianD
11-01-2015, 01:19 PM
Adrian, it seems like you might have an issue between the fuel filter and the tank. Others have reported a loose or damaged pick-up tube in the tank, or cracked hose from tank to fuel filter. If there was no air in lines before start but air after engine was circulating fuel, it could be issues at the tank or possibly with the low or high pressure fuel pumps sucking in air when they are operating. It might require a scan with the correct scanner to diagnose.

Do the foam/bubbles eventually disappear, or are they constant? If they go away at some point, but there is no visible air before starting, there must be a big chunk of air SOMEWHERE that shows itself after circulating the fuel. An air leak between the high pressure pump and the return line coming back to the fuel filter might not show in the clear lines, and there wouldn't be a fuel leak because the fuel simply goes back to the tank as air gets in. The slight vacuum created by the fuel returning to the tank would prevent fuel from leaking out of the system, so a leak at the top of the system, at the injector return lines, wouldn't show much if a sign of leakage, but maybe a little. I'd inspect under the injector cover to see what's happening up there.

The foaming would disappear. It was always there since I changed the fuel line. I don't have the injector cover, my engine is always naked :)

To conclude this story:
I've replaced the fuel filter with a Mann without the drain hole and water sensor and all is well. No more foaming on cold start like it did before and no more stalling :)
It was tested after a cold night and with the car parked on a slope, with the front pointing up.

Thank you everyone for the clarification, especially that on the leaks between filter and low-pressure pump.