How long should I have to crank after injector replacement (OM616)? - Page 8 - PeachParts Mercedes-Benz Forum

funola · #**106** 08-07-2012, 08:15 AM

Re reading your post,, you did say you saw bubbles in the brown line. if you are sure of that, skip replacing that line, and fix the leak(s) which still exists in the lift pump.

layback40 · #**107** 08-07-2012, 10:08 PM

If you are playing with fuel lines, you could try running from your bottle direct to the lift pump & then from the lift pump to the IP. This will show you if the filters are the problem. I have known it to take as much as 5 minutes of running to get all the residual air out of the system.

BodhiBenz1987 · #**108** 08-08-2012, 07:37 PM

Replaced primer pump, did not help. Bypassed primary filter, did not help. There is a hissing sound that does come from what sounds like the secondary filter area, but honestly even with a stethescope I can't tell. I can pump the primer for a while without seeing any bubbles anywhere. When I crank the engine (no start at all), leave it, then walk around and pump the primer pump, massive amounts of bubbles come through the line from pressure valve to secondary, but not the one from the lift pump. I can bleed out the air using the hand pump and get solid fuel again, but once I crank again, same deal. So basically cranking the engine seems to draw in the most air, and I can't look closely at anything while I'm cranking the engine. What's driving me nuts is, one time I'll see bubbles in one line, the next time, I won't. I can't expect advice when my observations keep changing.
I don't see any point in doing all the stuff I've done over again. Every seal on the lift pump is brand new and tight and the primer pump is brand new, every seal on the secondary filter housing and associated lines is brand new and tight. Seals on pressure valve new and snug. Everything clean and inspected for cracks/damage.
I guess before I try anything else (or give up) I will have someone crank while I watch to decide whether the bubbles are actually coming in that line from the lift pump or not when the engine is cranked.

vstech · #**109** 08-08-2012, 10:06 PM

go to ANY autoparts store, and buy a remote crank trigger... hook the clips to the large and small bolt on the starter, and use THAT to crank the motor.
another thing you can do.
fit a shop vac hose tightly into your fuel tank fill neck, set the shop vac on blow, and it'll build a psi or two on the fuel system. ANY leaks will weep wet. Fix them.

BodhiBenz1987 · #**110** 08-08-2012, 10:28 PM

Quote:

Originally Posted by vstech

go to ANY autoparts store, and buy a remote crank trigger... hook the clips to the large and small bolt on the starter, and use THAT to crank the motor.
another thing you can do.
fit a shop vac hose tightly into your fuel tank fill neck, set the shop vac on blow, and it'll build a psi or two on the fuel system. ANY leaks will weep wet. Fix them.

I actually have a remote ... I'll try that instead of bungie-cording my camera to the fender and trying to record while I crank.

funola · #**111** 08-08-2012, 10:57 PM

Quote:

Originally Posted by vstech

go to ANY autoparts store, and buy a remote crank trigger... hook the clips to the large and small bolt on the starter, and use THAT to crank the motor.
another thing you can do.
fit a shop vac hose tightly into your fuel tank fill neck, set the shop vac on blow, and it'll build a psi or two on the fuel system. ANY leaks will weep wet. Fix them.

BB is running out of a gallon jug. Even if she was not, pressurising the tank will only test components before the lift pump.

BodhiBenz1987 · #**112** 08-09-2012, 12:12 AM

Quote:

Originally Posted by funola

BB is running out of a gallon jug. Even if she was not, pressurising the tank will only test components before the lift pump.

Any leak after the lift pump should be weeping when I pump the primer, or crank, shouldn't it? That's what I don't understand ... there's not diesel coming out anywhere unless I've got a bolt cracked. I did notice (just today) it looks like the gasket between the secondary filter and the filter housing is collecting a tiny bit of diesel but it's definitely on tight (I don't want to tighten it too much). I am going to try to clean everything up tomorrow so I can make sure it's not just fuel that's been collecting during bleeding. Or I might let it sit a day and enjoy some fresh, non-diesel-smelling air to clear my mind-set.

funola · #**113** 08-09-2012, 07:58 AM

Quote:

Originally Posted by BodhiBenz1987

Any leak after the lift pump should be weeping when I pump the primer, or crank, shouldn't it?,......

when cranking only. it is also possible that a leak will suck air but not leak fuel, acting like a 1 way valve, making diagnosis difficult and confusing.

funola · #**114** 08-09-2012, 08:03 AM

check parts diagram to see if there is supposed to be an oring or a washer on the 24 millimeter filter housing bolt.

BodhiBenz1987 · #**115** 08-10-2012, 12:44 AM

Quote:

Originally Posted by funola

check parts diagram to see if there is supposed to be an oring or a washer on the 24 millimeter filter housing bolt.

There is a washer under the bolt head (per the EPC) and an o-ring on the stem of the bolt ... I replaced both ... I thought maybe the washer would help since the old one was pretty rough but no luck.
I did try cranking with the remote today and could not see bubbles in either the line from the lift pump to secondary filter, or secondary filter to IP. It was still very hard to see due to the browned lines and the engine rocking a lot as it cranked but I'm pretty sure there were no bubbles. Except ... when I stopped cranking, I saw a couple tiny stray bubbles that looked like they came out of the IP backwards into the line from the secondary filter. As usual, I saw lots of bubbles coming out of the line attached to the pressure valve.
I will try replacing the seals/cleaning the banjo connection on the outside of the IP.

layback40 · #**116** 08-10-2012, 03:22 AM

You may have air in the injector return lines that is getting back to the top of the filter housing & so ending up in the line from the banjo to the filter.
If you could start it again & dont try & idle for at least 20 minutes of running. You could see if the injector return lines eventually clear. Best to rev it up & down to clear the air out but dont let it return to idle.

funola · #**117** 08-10-2012, 08:18 AM

Quote:

Originally Posted by BodhiBenz1987

There is a washer under the bolt head (per the EPC) and an o-ring on the stem of the bolt ... I replaced both ... I thought maybe the washer would help since the old one was pretty rough but no luck.
I did try cranking with the remote today and could not see bubbles in either the line from the lift pump to secondary filter, or secondary filter to IP. It was still very hard to see due to the browned lines and the engine rocking a lot as it cranked but I'm pretty sure there were no bubbles. Except ... when I stopped cranking, I saw a couple tiny stray bubbles that looked like they came out of the IP backwards into the line from the secondary filter. As usual, I saw lots of bubbles coming out of the line attached to the pressure valve.
I will try replacing the seals/cleaning the banjo connection on the outside of the IP.

Did it start when you cranked with the remote (Key must be in the run position)?

I don't think you ever mentioned nor was it asked:

Are the injector hardline unions dry (under and above the nuts)?

Are injector halves dry?

Injector daisy chain return lines dry?

Injector return end cap dry?

Any wetness in these areas are air entry points.

BodhiBenz1987 · #**118** 01-12-2013, 06:06 PM

Been an epoch since I updated this thread, mainly because I've had nothing to update it with but frustration, cursing, madness and running in circles. I also took a couple lengthy breaks from the whole thing to clear my mind.
Anyhow, it is now running, as of Thursday evening.

https://www.youtube.com/watch?v=w2xHTD-0H8k ... https://www.youtube.com/watch?v=Nw6h0Y1Mjw0 ... took it for a drive Friday and it felt pretty good ... now has a slight nailing when warm and still shakes (but less than before this whole saga started). The saga isn't over, but this is a big victory for me. Here's the backstory between now and when I left this thread off (possibly forgetting some things).
I continued to suspect the problem was the hoses, lift pump, filters, or something in that vicinity, because those made the most sense as air entry points into the IP. I changed the return lines (again) for good measure, and changed that little end cap on the final injector (had re-used the original and figured maybe it was brittle). I changed the secondary filter head to one with the updated center bolt. I changed the secondary filter and primary filter again (and tried bypassing the primary altogether). I finally decided to replace the clear fuel hoses around the IP, despite wondering if it was a waste of money to buy brand new ones. It didn't help the problem, but it provided a clue: With new clear lines in place, I could see, clearly, that despite what I thought I saw earlier, there were not bubbles going from the secondary filter into the IP. Another thing I noticed was that only did the air present itself coming out of the IP after cranking ... when hand priming, it would clear.
That kind of narrowed it down to either being a problem in the IP (including me just not priming correctly) or a problem in the injectors.
Through some level of trial and error and the various input of others (as usual, would not have gotten anywhere without that), I did discover that the car would run on three cylinders ... only so long as I left the No. 3 injector line cracked. It would run and run on three, with foam/bubbles pouring out of that line pretty much indefinitely. Once that line was tightened, the whole engine eventually cut out, and then the bubbles would appear in the line out the back of the IP. I could bleed the whole thing again, but never the No. 3 line.
Having that narrowed down, I figured it was either something internal in the pump specific to that element or an injector issue. Did not have an extra injector, so I swapped the suspect No. 3 injector with the No. 2. Lo and behold the No. 3 line now bled easily, and the No. 2 spewed endless air. At that point I ordered a used injector off eBay and popped it in. Left that nut cracked, started it on the other three cylinders, watched a little air come out, then spurts of solid fuel ... tightened it and the car ran.
So one way or another, the problem was one of the new remanufactured Bosch injectors. In hindsight that was kind of the Occam's Razor: If something works (even not very well) and you replace something and it immediately stops working, look at what you replaced.
Anyhow, I took the suspect injector back to the dealer and they said I can send the set back under warranty. I noticed one of the working injectors (still on the car) was leaking at the nozzle holder junction. The downside of sending them back (aside from the fact that who knows what I'll get in the next batch) is I can't really determine exactly what was wrong with that injector. My theory was that there's something wrong internally that it's letting compression gasses backward up the injector and out the top. I guess it could also be the return barbs or a leak where the nozzle holder screws together, but I don't understand why that would cause air to shoot out as if pressurized. And presumably go back into the IP and fill the whole system with air. Anyhow, I can't take it apart to find out because that will void the warranty.
Before I remove the remaining injectors, I'm going to get it warm, so I can try a compression test again (might as well).
Hopefully that long story made some sense. I'm feeling sick today on top of not being in the best mood since i'm losing my job as of Monday (again). It was a good feeling to get the car running and I would love to hear if anyone else has had an issue with a remanufactured injector like this, or just has a theory on what was wrong.

Silber Adler · #**119** 01-12-2013, 08:25 PM

Amazing story,
Will keep it my memory.

funola · #**120** 01-13-2013, 11:40 AM

I was wondering if you gave up. Good you stuck with it and finally found the cause. When working on the fuel system, always change one thing at a time then start the engine and check for bubbles in the return line to tank.

Maybe you should show this thread to the dealer and see if they're sympathetic and give you a break on parts. They really should with all the money and grief you suffered with a bad new injector you paid good money for.

The only way to tell if an injector is functioning properly is to pop test and observe pattern, opening pressure, leaker or not. If you have a fuel injection shop nearby, maybe worthwhile doing that with the new set. Ask them if you can watch. Good learning experience.