Advice needed please - Page 3 - PeachParts Mercedes-Benz Forum

kerry · #31 07-23-2008, 09:26 PM

Quote:

Originally Posted by miljohnj5

Yes- about as much. I had 3/4 tank and about 10 gallons came out with a little left in the tank which we later drained and replaced with good diesel. At which point it started to run better then got worse than before. Sorry about the sporadic details- how can we bleed the fuel lines to get rid of the air pockets?

I would start with an alternative fuel supply as I described to rule out any air getting in thru the fuel lines. Rig up the bottle and pump the primer at least 100 times or so, then give it a try.

Hatterasguy · #32 07-23-2008, 09:32 PM

Did you drain some fuel into a clear can and let it sit? This is sounding less and less like a fuel problem. Anything those morons could have put in your tank from sugar to piss would have been removed by the fuel filters.

When you changed the spin on did you pour the contents into a clear jar? See any water?

Skippy · #33 07-23-2008, 09:33 PM

If it still isn't starting after using the primer pump a lot-until it gets hard to pump, you can also try cracking (loosening) the injector lines at the injector and cranking over on the starter for 20 or so seconds at a time, waiting in between to let the starter cool off. You should start getting fuel out of the injector lines after one or two tries. As each line starts pumping a good amount of fuel, tighten it back down. The engine will probably start before you get all the air out. If it does, just let it run for a few seconds, then shut it off and tighten the rest of the injector lines. After that you should be good.

miljohnj5 · #34 07-23-2008, 09:45 PM

-We drained it to let it settle and didn't notice any difference in appearance, neither with water nor settled residue.
-I will try the alternate source after pumping it a great deal tomorrow.
-The last thing we tried was to crack the lines at the injectors and nothing- that's the hang-up now, no fuel is making it there. Plenty of fuel past the primary filter into the injector pump but nothing out. We also tried cracking the lines at the injectors when it was running and they all were being fueled well enough so that when they were cracked the engine idle would start to slow down quite fast. Was that a bad move by cracking them open while it was running, enough to let air in?

Hatterasguy · #35 07-23-2008, 09:48 PM

No, cracking them while its running is how you bleed them an isolate problems.

Sounds almost like the lift pump craped out, what does the lift pump on a 617 look like? I don't remember.

kerry · #36 07-23-2008, 09:58 PM

I agree that a bad or weak lift pump is a possibility.
Did you fill the primary filter with fuel when you replaced it?

miljohnj5 · #37 07-23-2008, 10:13 PM

The guy helping me is willing to get on this forum. His forum name should be Roger Nappier. He's trying to help as much as possible. Please describe the lifter pump. It's NOT the primary/spring button primer correct? So the lifter pump is part of the injector? Also, do air bubbles matter in the primary fuel filter? Mine has always had an air bubble and its ran fine until now.
-The secondary filter was filled before replacing it.

kerry · #38 07-23-2008, 10:22 PM

Primer pump attaches to the lift pump which is attached to the IP. It is mechanicaly operated and can be tested by removing the line which goes from it to the secondary filter and seeing how much it pumps while turning the engine over with the starter.
I should have asked if you filled the secondary filter, not the primary.

When you say there is plenty of fuel going thru the primary filter but none going thru the injection pump, where are you testing this? The fuel flows from the tank thru the primary filter, into the lift pump, is pumped by the lift pump thru the secondary filter and then into the injection pump then out the hard injection lines.
Where in that route are you saying that the fuel stops?

STJAMES · #39 07-23-2008, 10:30 PM

I am the man working on the above post. When the car does not start when cranking has fuel coming out of canister fuel filter lines and line into injector pump.but when i crack lines at injector or on top of injector pump no fuel at all clear pre filter has fuel but small air bubble but with air bubble i still have fuel at injector pump inlet but not on outlet side?

miljohnj5 · #40 07-23-2008, 10:38 PM

Quote:

Originally Posted by kerry

Primer pump attaches to the lift pump which is attached to the IP. It is mechanicaly operated and can be tested by removing the line which goes from it to the secondary filter and seeing how much it pumps while turning the engine over with the starter.
I should have asked if you filled the secondary filter, not the primary.

When you say there is plenty of fuel going thru the primary filter but none going thru the injection pump, where are you testing this? The fuel flows from the tank thru the primary filter, into the lift pump, is pumped by the lift pump thru the secondary filter and then into the injection pump then out the hard injection lines.
Where in that route are you saying that the fuel stops?

The fuel seems fine at the secondary filter. From there, I'm pretty sure we only looked at the block side of the hard lines where it was intially alright then later, dry as a bone. I don't think we looked at the fuel leaving the secondary pump. For which it requires the lifter pump to pump fuel past the secondary and into the hard lines? I just spoke with the mechanic on the phone and asked about it and he said he checked the hard lines at the injector side and nothing. I apologize but I don't remember.
If someone would prefer to communicate directly with him, his cell is 573 261 0182 He might have a more accurate description, mechanically speaking, as a certified GM mechanic.

kerry · #41 07-23-2008, 10:42 PM

Small air bubble in pre-filter is normal. People with more experience than me need to jump in here. I'd say there is still a possibility that there is air in the injector pump that needs to be bled out. I'd loosen the hard injector lines and pump the primer pump many times to try to get air out of the injection pump. There have been a number of cases on this forum where it was hard to bleed the air out but it eventually did come out and the engine ran.

kerry · #42 07-23-2008, 10:56 PM

Small air bubble in pre-filter is normal. People with more experience than me need to jump in here. I'd say there is still a possibility that there is air in the injector pump that needs to be bled out. I'd loosen the hard injector lines and pump the primer pump many times to try to get air out of the injection pump. There have been a number of cases on this forum where it was hard to bleed the air out but it eventually did come out and the engine ran.

STJAMES · #43 07-23-2008, 11:05 PM

I should say the car has started many times today I got the car to stall in park twice by reving the motor in park And after it stalled the first time I checked fuel at injector none out of canister filter had fuel at inlet and outlet tighten lines back starting back up ater sitting a few minutes reved up fine ,got car to stall again same problem, removed line going into injection pump fuel pump out when cranking,tightened back up cracked three lines on top of pump no fuel at all

kerry · #44 07-23-2008, 11:19 PM

Seems like air is getting into the lines somehow or the lift pump is failing. I'd try an alternative fuel source in a bottle high enough for gravity to overcome any lift pump problems.

raslaje · #45 07-24-2008, 12:33 AM

Here's the FSM section on Venting Injection System you can download from Zshare

07_1-140.pdf - 0.19MB