How long should I have to crank after injector replacement (OM616)? - Page 5 - PeachParts Mercedes-Benz Forum

funola · #61 07-03-2012, 10:15 PM

Try this:

With all seals tight, crack open the banjo bolt on the fuel pressure relief valve on the IP (backside, facing the block near the temp sender), then use the primer pump to get the air out of the filter and IP. Tighten the banjo bolt. Make sure all 4 glow plugs are good and getting voltage. Crack one injector nut and crank till it starts, tighten the injector nut and feather the throttle and watch the clear return (cigar hose replacement) line till the bubbles clear.

If you can't get it to start after all of the above or can't get the bubbles to clear if it starts, you need to get the Mityvac out and find where it is leaking air in.

BodhiBenz1987 · #62 07-04-2012, 06:47 PM

I doublechecked the fitting around the primary filter (which is new) and tightened the hose clamps a little bit. The supply hose should be good, I just bought it. I made sure it is fully submerged in the bottle of diesel. When I pump the primer I can see the hose pulse (if that's the right word). I can't see any air in the primary filter (not even the normal bubble). I tried:
-cracking the bolt that goes from the secondary filter housing to the IP and pumping. Diesel (no bubbles) comes out.
-cracking the banjo bolt on the side of the IP near the temp sender and pumping. Diesel comes out without bubbles. I pumped a bit of diesel through then tightened it.
-adding the clear tube where the cigar hose was on the last injector. I can see diesel begin to rise in it when I pump the primer, but not a lot.
-cracked the injectors nuts again. Bubbles and fuel came out of 1 and 2, closed them once it was steady fuel. Cranked again until bubbles and fuel came out of 3 and 4. Fuel now coming out of all four. Tightened.
-recharged battery (overnight)
-checked voltage on all four GPs
-cranked with throttle all the way open ... it is not starting. It is now back to (what sounds like) catching on a couple cylinders and sounding like it's close to starting, but no go.
Also tried, for the heck of it:
-removed vaccuum line from shutoff valve
-removed crankcase hose in case it was maybe obstructed and causing back pressure

I am not getting a huge stream out of the return hose in the bottle when I pump the primer, but it is a small steady stream. I tried submerging that hose to see if air was coming out and it wasn't. I'm not seeing air bubbles moving through the hose on the back of the IP anymore (which I was getting yesterday), but there is a big fat air bubble sitting on the top of it, near the spin-on filter. Nothing happens to the air bubble when I pump, regardless of what bolt is cracked. It's just sitting there peacefully, and it got a little larger overnight. I'm assuming there is not supposed to be a bubble there? I can post a photo if it isn't clear which hose I'm talking about.
If my dad wants to stop by when he's done working this evening, I will try the WD40. I have not yet ... I assume there's not point in trying to spray it myself and then start ... it would just end up in a puddle in the air filter housing, right? I have a feeling it will start and just die out again, but I guess it is worth a try in case my bleeding efforts made any progress and there's just a little air left.
Only thing I haven't done yet is take the glow plugs out to watch them and make sure they glow fully ... guess I will try to do that now without burning myself or something else. Would also be easier with a helper.

Hope everyone is having a good holiday.

BodhiBenz1987 · #63 07-04-2012, 07:45 PM

Update: It started again, and ran a while at part throttle ... better than the last time. Stayed pretty even at 1,500 rpm. When I tried to let off a little to see if it would idle, it quit.

I can't see whether there's fuel and/or bubbles in my clear line. I made a video but it will take me the rest of the night to figure out how to get it on my computer.
That sounds like progress, but now I'm back to ground zero. Won't start again. Bubbles gallore. It's sucking them in somewhere. Again, all the bubbles are in the line between the pressure valve and the spin-on filter. A bunch of them moved through the line as I pumped, but now there's just that big pocket of air at the top again.
I guess the next step is to find the leak. There doesn't seem much point going through all the priming again until I've done so.

funola · #64 07-04-2012, 07:52 PM

Looks like you have bled it well enough and it should have started. The fact it had not a hint of firing is baffling. Have you adjusted the valves since the last time it ran? Is the shut off lever on the IP in the correct position and not in the shut off position? I mentioned it before, that lever can be put into a position to not let fuel through normally (happened to me after a valve adjustment, which required removing some of the linkages).

Can't hurt checking the glow plugs for actual glow. Make a video so we can hear how fast your starter is cranking. The bubble getting bigger overnight indicates an air leak. There should be no bubble in any fuel lines after all air has been bled out from running the engine.

Brian Carlton · #65 07-04-2012, 08:00 PM

I suffered similar symptoms with an aftermarket, clear primary filter. The filter looks perfectly clean, but the inlet and outlet are of a reduced size and quickly restrict the flow. The lift pump is more than happy to suck air past the filter clamps. The clamps are capable of restricting liquid fuel from flowing..........they are not capable of restricting air from going the opposite direction.

Lesson cost $150............for a fuel pump that was not required.

Lesson learned: Use OE fuel filters.

funola · #66 07-04-2012, 08:04 PM

Congrats! looks like it's an air leak problem after all! Try tightening the lift pump fittings and primer pump. Did you have the correct seals when replacing the fuel filter? Make sure those are clean and tight.

If you took the video on your phone, upload it direct to youtube need to register first) then post the link.

Brian Carlton · #67 07-04-2012, 08:15 PM

Quote:

Originally Posted by funola

Try tightening the lift pump fittings and primer pump.

You can tighten until your wrist fails. It will not prevent air from leaking past the clamps under the condition of a inline fuel restriction.

funola · #68 07-04-2012, 08:33 PM

Quote:

Originally Posted by Brian Carlton

You can tighten until your wrist fails. It will not prevent air from leaking past the clamps under the condition of a inline fuel restriction.

How can you be so sure it is a inline fuel restriction? Even if the primary filter is a cheapo imitation, and the i.d on the barbs is less than 1/8", that is not enough of a restriction at idle for it to suck air. I can see if the filter is made from 2 halfs molded together, that the rough seam may cause a leak.

At this point, it's time to Mtyvac each component till the leak is found.

Brian Carlton · #69 07-04-2012, 08:38 PM

Quote:

Originally Posted by funola

How can you be so sure it is a inline fuel restriction? Even if the primary filter is a cheapo imitation, and the i.d on the barbs is less than 1/8", that is not enough of a restriction at idle for it to suck air.

That would be a factually incorrect statement. The inlet and/or outlet provides the restriction with some foreign material of some sort.

funola · #70 07-04-2012, 08:52 PM

Quote:

Originally Posted by Brian Carlton

That would be a factually incorrect statement. The inlet and/or outlet provides the restriction with some foreign material of some sort.

.

Again, how can you be so sure it's a primary filter restriction? It can be that, or the hoses connecting it, or the lift pump, or the primer pump, its washer, or the hose between the lift pump and the secondary filter. Until each component is tested with a Mityvac, we won't know. Just because you had a bad primary filter does not mean BodhiBenz's also has a bad one.

Do you still have that cursed after market primary filter? I would love to run it and see what's the real scoop with it.

Brian Carlton · #71 07-04-2012, 09:09 PM

Quote:

Originally Posted by funola

.

Again, how can you be so sure it's a primary filter restriction? It can be that, or the hoses connecting it, or the lift pump, or the primer pump, its washer, or the hose between the lift pump and the secondary filter. Until each component is tested with a Mityvac, we won't know. Just because you had a bad primary filter does not mean BodhiBenz's also has a bad one.

Do you still have that cursed after market primary filter? I would love to run it and see what's the real scoop with it.

You asked two different questions. The first was whether I know if it is an inline fuel restriction. Of that I am certain.

The second, in this post, questions whether I can be sure that it is a primary filter restriction. I never stated with any certainty that it was a primary filter restriction. I stated that my own situation was a primary filter restriction. I cannot be sure of where the fuel restriction is other than somewhere between the tank and the lift pump. The primary is a good candidate to check first.

In my own suffering, I determined, finally, that the aftermarket primary was the culprit. It was not without a very expensive and time consuming lesson.

I did have it here and I was planning to photograph it and put it on the forum as a lesson to others. But, unfortunately, it disappeared.............

It would have made quite the experiment for you................

BodhiBenz1987 · #72 07-05-2012, 01:29 AM

OK guys, here is the video I took earlier. It's not the greatest angle but considering I did it with the camera propped under the hood, it's not bad.

240D trying to start/run - YouTube ... it sounds like it's nailing too but I guess that could be from the air. At times in the video it sounds like it's idling, but I actually have the pedal down a bit to achieve that. You can tell the times when I try to ease off the pedal, where the engine starts to shake and die out. I didn't shut it off at the end, just took my foot off the pedal. It would not start again, and as I mentioned sure enough I found lots of bubbles when I tried to prime.
The filter I put in is an MB filter from the dealership, but the hose is not (I got it from Pep Boys). The new filter and new hose both came after this problem started ... though that doesn't mean they aren't part of the problem.
I'll start at the filter and move downstream. One thing that puzzles me though is I have yet to see bubbles in the clear lines from the lift pump to the secondary filter, or secondary filter to the IP. Just in the one from the pressure valve. Maybe I'm just not seeing them because the lines are hazy, or they're zipping through there while I'm cranking or revving.

funola · #73 07-05-2012, 10:04 AM

I have not been able to look at the video on a big screen so can't see any details of air bubbles. It sounded like it was running on all four so the good news is your injectors are ok.

You said: "I have yet to see bubbles in the clear lines from the lift pump to the secondary filter, or secondary filter to the IP. Just in the one from the pressure valve." Are those lines new? If they are old and brown, it would be difficult to see air bubbles. What did the clear temporary cigar hose replacement show? There should have been lot's of bubbles there when you had it running. That is the best place to look for bubbles, since all air ends up there (pri and sec filter, IP, injectors) Once you have solid fuel there and bubbles do not show up later, your fuel system is tight.

funola · #74 07-05-2012, 10:18 AM

Don't forget the injector daisy chain return lines. They can leak and cause problems too. If you re-used the old lines and did not cut the ends back as a precaution, they are most certainly leaking. Best to just replace them with new from the dealer.

BodhiBenz1987 · #75 07-10-2012, 10:34 AM

Unencouraging update: I changed and tightened the lines on the primary filter, with factory brand lines, and checked with a mitivac to make sure air wasn't getting past the primary filter connections. I also changed the return lines with new factory line. I'm just getting froth in the line from the lift pump to the spin-on now, and I can see little bubbles coming into the primary filter, but from the lift pump side (i.e., against the fuel flow). One end of the hose is submerged, it is tight on both barbs of the filter (and the filter looks unobstructed). The fitting is as tight as I could reasonably get it on the intake to the lift pump, and I cleaned that fitting before putting the hose on it. I'm considering replacing the primer pump and see if that helps. I don't know if or how they break, but it sounds like an air pump when I'm pumping it ... granted that sound could be coming from somewhere else down there. Is there a way to test which part of the lift pump is leaking? I don't have the money to just buy parts I hope fix the problem.