w210 OM606 Diesel Fuel purge (remove air) - PeachParts Mercedes-Benz Forum

michakaveli · #1 08-25-2007, 09:16 PM

Hey guys, need some help. I replaced the o-ring's on my plastic fuel lines w/ Viton replacements and completely replaced the short plastic fuel line from the pre-filter to the heat exchanger. I trying to start the car and purge the air from the system in the process.

So far, made sure the lines are back on snug and clipped into place. I have been cranking the engine (while being jumped off of my Neon not to kill my battery) for approx. 30-45 second intervals, 2x so far. My GF can see that essentially all of the plastic fuel lines appear to have fuel running through them while cranking, but the newly replaced, plastic fuel line from the pre-filter to the heat exchanger appears to be flowing from the pre-filter to the heat exchanger. I thought the fuel in this line was supposed to flow the other way?

I have included a photo to show my current fuel line connection(s) I am 99% sure they are in correct order. At least while cranking there are no visible large leaks that have appeared. That's a good sign I hope. How long do I crank or should I crank before this thing catches?

Like I've stated, I've done 2 cycle co far as I don't want to burn up the started. I replaced the pre-filter and full flow filter w/ new units and refilled the full flow prior to re-intalling....

michakaveli · #2 08-25-2007, 09:49 PM

Tried it for a 3rd time but before I unscrewed the full flow filter to see if it had some fuel in it and it was full. Cranked again for 40 seconds w/ an occasional sputter, maybe 3 times but no go. I rolled her back into the garage for the night...

TMAllison · #3 08-25-2007, 10:43 PM

Quote:

Originally Posted by michakaveli

Tried it for a 3rd time but before I unscrewed the full flow filter to see if it had some fuel in it and it was full. Cranked again for 40 seconds w/ an occasional sputter, maybe 3 times but no go. I rolled her back into the garage for the night...

I am virtually certain you have the two lines comming off the lift pump reversed.

The short line should connect to lower/outer leg of the lift pump and then beneath the S/O valve You've got it on the upper part of the lift pump.

Reverse those two and life should be good again.

michakaveli · #4 08-25-2007, 10:52 PM

Quote:

Originally Posted by TMAllison

I am virtually certain you have the two lines comming off the lift pump reversed.

The short line should connect to lower/outer leg of the lift pump and then beneath the S/O valve You've got it on the upper part of the lift pump.

Reverse those two and life should be good again.

It may be possible. I did forget which went where and saw a photo on this forum and appeared to have had it. I will reverse tomorrow and repeat back.

Thank You!

nhdoc · #5 08-25-2007, 11:24 PM

When I first bought my '98 I brought it to a well respected MB shop in Mass to have the fuel lines replaced among other things done. When they were done with the work they cranked and cranked it and it would not start. They killed the battery and while they waited for it to charge a little I pulled out the diagram I had from the EPC and showed them two of the lines were reversed. They absolutely denied it could be possible.

They kept cranking and still nothing. I told them to reverse the two lines and I would accept full responsibility for it but put a side bet of 20% of the service cost that it would fix it. Of course it fixed it, and I saved $120 on the day's work but they still could not believe they screwed it up...you have the exact same error on yours...check the lift pump against the attached diagram and switch the lines on it and the car will start right up.

By the way, after that experience I never let another tech touch my car.

deltajetfixer · #6 08-25-2007, 11:42 PM

Quote:

Originally Posted by michakaveli

I have included a photo to show my current fuel line connection(s) I am 99% sure they are in correct order. At least while cranking there are no visible large leaks that have appeared. That's a good sign I hope. How long do I crank or should I crank before this thing catches?

Confirmed...the 1% got ya!

The lift pump lines are reversed. If you look at the lower diagram in the link provided, you'll see this as well as the fact that you're missing items 81 and 82 which is a spacer that clips between the two lines.

If you have the spacer, you'll find that it fits MUCH better with the lines routed the correct way. You can guess how I know

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=210025&M=606%2E962&GA=722%2E608&CT=M&cat=19T&SID=07&SGR=120&SGN=04

raMBow · #7 08-26-2007, 12:44 PM

I will soon be replacing my lines and doing my lines, been sitting here for 6 months, and doing the viton etc. Motivation is finally getting to me as I now have a wet spot on a line at 106,000.

At any rate I too have heard problems of the cranking after replacing and too much air in the lines etc.

Silly thought, what if you replaced a line or two (without taking the IM off), less likely to get something swapped around, then ran it a little while to clear that air, then another line or two, run, and another, then off with the IM and do the final ones you could not reach. Extra work, but might reduce the air issues etc.

TMAllison · #8 08-26-2007, 12:55 PM

Quote:

Originally Posted by raMBow

Silly thought, what if you replaced a line or two (without taking the IM off), less likely to get something swapped around, then ran it a little while to clear that air, then another line or two, run, and another, then off with the IM and do the final ones you could not reach. Extra work, but might reduce the air issues etc.

No need to pull IM. If agile you can remove WW bottle and reach under.

Your one at a time priming idea sounds hot to me and not in a good way.

I'd suggest a full tank, refilling the filter afterwards and parking the rear wheels on a 2 x 4 if you are worried about getting it primed again.

michakaveli · #9 08-26-2007, 02:01 PM

Ok guys, REPORT. Good and Bad news.

GOOD NEWS: Swapped the two lines around as mentioned and it did indeed help! I did have to crank 2 times, 1st around 30-40 seconds with stumbling (music to my ears at the time). My battery was getting weak, even though I had it jumped to my Neon w/ heavy 4 gauge at least jumper cable. I stopped cranking and charged up off the Neon as she sounded like she was wanting to come to life. Touched the starter and she wasn't too hot yet (warm :-) , so I proceeded a second round. After about 30 seconds she roared to life. Revved her up slightly to help clear out some air then let her idle. She idles nice and I don't feel the slight stumbling in the steering wheel like before.

BAD NEWS: I proceeded to the engine area while she was running. I examined the fuel lines while she was running at idle and didn't see any air bubbles. I revved her up manually and low and behold, I see the same air bubbles as I did before, but the engine did not visibly stumble as before the o-ring replacement.

NOTE: When I swapped the lower fuel lines as addressed earlier in this thread, the line going into the upper opening on the lift pump is not very snug. I don't see any fuel coming out (yet) but feel this is where the air maybe still be coming in through. The lower opening on the lift pump has the fuel line snug onto it. By snug meaning I can grab the fuel line on the threaded area after the joint, wiggle the line and the line won't move. Not the case with the upper line.... I will include the fuel line diagram from the prior post, and the affected line that I stated feels loose (non-snug) is 83. I have also included photos of how the lines currently appear. From this diagram lines 83, 74 and 56 visibly have air bubbles.

PHOTOS:
- My connection of line 83 is [Image 3]
- My connection of line 74 is [Image 2]
- My view of pre-filter to thermostat fuel line [Image 1]
- My marked photo to which lines visibly have air bubbles circulating through under throttle [Image 5]

NOTES for STARTING: Prior to commencing any starting activities I always jump my car to another vehicle (donor) to conserve and assist the E300's battery during starting duties. Once connected and the donor car running I commence with the glow plug sequence and wait at least 15 seconds to help the battery slightly recharge from the glow plug system drain on the system and letting the glow plugs heat up nicely. After the 15 or so seconds I proceed with the cranking of the engine continuously for approx. 30-45 seconds. I won't crank longer than 45 seconds for fear of overheating the starter. The key is to maintain sufficient power flow to allow the engine to keep cranking. Hope this helps someone :-)

TMAllison · #10 08-26-2007, 02:12 PM

Some of your horsehoe clips are not fully retracted. They may not have seated and clicked into place fully. Redo those.

See top/inner line at lift pump and right side of S/O valve viewed facing it.

If the photo of the line to the pre-filter was taken with engine off that is fine. If taken with engine on you have a bad seal at one or the toher end of that line, or beneath the pre-filter itself. If engine was on fix that one first.

michakaveli · #11 08-26-2007, 02:17 PM

Additional note. There are air bubble at idle as well.

michakaveli · #12 08-26-2007, 02:18 PM

Quote:

Originally Posted by TMAllison

Some of your horsehoe clips are not fully retracted. They may not have seated and clicked into place fully. Redo those.

See top/inner line at lift pump and right side of S/O valve viewed facing it.

If the photo of the line to the pre-filter was taken with engine off that is fine. If taken with engine on you have a bad seal at one or the toher end of that line, or beneath the pre-filter itself. If engine was on fix that one first.

Pre-filter was taken w/ engine off.

nhdoc · #13 08-26-2007, 02:26 PM

Quote:

Originally Posted by michakaveli

Pre-filter was taken w/ engine off.

There is normally a bubble in the line feeding the pre-filter when the engine is off, so do not be concerned about that one at all. Make sure all of the other lines are secured and the clips are correctly positioned (they need to be loose, not pressed up against their ends). If you still have some bubbles in the lines it may just be the residual air in the system from opening it up...take it for a drive and see if it clears up some after that...it might just be normal.

You didn't mention replacing the o-ring at the prefilter housing itself...this is the most likely cause of air in the fuel system...did you replace that one???

michakaveli · #14 08-26-2007, 02:32 PM

I'm going to replace the line going to the lift pump. They are both slightly wet around them, not dripping but shiny form fuel. I have already removed those at least 2 times so far and feel I have worked those plastic slips to the limits. All other line are much tighter than both of these.

TMAllison · #15 08-26-2007, 02:52 PM

if you've got the viton orings try slipping a new one on those lines; they are what snug things up. Both those should be the smaller of the two sizes.

I've had to use a pair of channel locks and gently squeeze one of those lines to get it to double click down into place and seal.