Very Hard Starting if under ½ of tank of fuel - PeachParts Mercedes-Benz Forum

ssorange · #1 10-29-2007, 04:12 AM

Year: 1988
Model: 190D 2.5 W201.126

Hi guys (and thanks ahead of time for your help),
My car has begun hard starting:
If the car has less than a half of a tank of fuel.
or
If I park the car with the front facing up-hill.
but
If I park the car with the front facing downhill it will start fine and runs fine.

I see a little bit of wetness on the top of the IP near the front two fuel lines.

When it is not starting and I disconnect the fuel line from the injectors and engage the starter there is no fuel. If I disconnect clear fuel line that runs from the fuel pump to the filter (at the filter) and engage the starter - no fuel. It will take 2-3 minutes before fuel gets back to the injectors. Then the car runs fine.

Thanks for your help!

Maxbumpo · #2 10-29-2007, 07:35 AM

Clearly you have a fuel leak that is allowing the injection pump to loose its prime. Fix the leak(s)...

Stevo · #3 10-29-2007, 10:07 AM

Your tank strainer could be plugged half way up.

Bens lover · #4 10-29-2007, 04:23 PM

Did you have a look ...Avery close look to your in line fuel filter

dave1980_300sd · #5 10-29-2007, 04:45 PM

it was the delivery valve seals. with a low fuel tank and parked facing uphill, it wouldn't start at all. My residual high school science knowledge leads me to think that if the delivery valve seals are leaking and the car is parked uphill with a low fuel tank, the IP becomes the high point in the fuel system. therefore, since the leak is on the IP, air gets sucked in at that point and the IP loses its prime.

I figured it out by noticing a slight hissing sound coming from the top of the IP after a period of cranking in an attempt to start the car. I looked closer and saw air bubbles. anyway, I dealt with it by only parking the car facing downhill (I live on a slope) until I had a chance to replace the delivery valve o-rings, at which point the problem was cured. also the top of the IP is now bone dry, whereas before it was always wet with fuel.

hope this helps,

- dave

Stevo · #6 10-29-2007, 06:01 PM

Congratulations...Good detective work. Your IP had O rings and copper seals both?

dave1980_300sd · #7 10-29-2007, 08:29 PM

sorry, my response made it sound like I was the OP. in my case though, yes, I replaced both the o-rings and the copper washers, and that solved the problem. thanks for mentioning the washers, I forgot about that.

I believe these are the part numbers for the washers and o-rings, cheap at the dealer:

1410-105-001
1410-210-014

can't remember which is which though.

at any rate, hope all this helps the original poster.

- dave

ssorange · #8 10-29-2007, 08:42 PM

Quote:

Originally Posted by dave1980_300sd

sorry, my response made it sound like I was the OP. in my case though, yes, I replaced both the o-rings and the copper washers, and that solved the problem. thanks for mentioning the washers, I forgot about that.

I believe these are the part numbers for the washers and o-rings, cheap at the dealer:

1410-105-001
1410-210-014

can't remember which is which though.

at any rate, hope all this helps the original poster.

- dave

Thanks for the info....Sounds like it is the same problem. So let me see if I've got this: you removed and replaced the delivery valve seals (copper) and O-rings (rubber) on the IP, correct? Did you need to get the special 32 tooth socket (Part No. 617 589 01 09 00) to loosen and tighten the tops of the delivery valves.

Thanks again! Looks like a trip to the deal. The tool appears to be expensive.

dave1980_300sd · #9 10-29-2007, 09:33 PM

yes, I got the tool at the dealer. it was about $45. I couldn't find it anywhere online much cheaper than that, and figured it was worth it to just be able to grab it at the dealer and do the job that much faster. still not too bad price wise... even including the tool it was barely over $50 total for me.

if you haven't already, it'd be a good idea to read up on delivery valve seal replacement in the archives... there are some parts of the delivery valves that you definitely don't want to remove. I used a pick and tried to disturb as little as possible when removing the copper washers (the o-rings come out with the part the special socket removes)... apparently going much deeper than the copper washer as far as removing things goes can cause big problems later on. the part immediately below the copper washer was hard not to disturb a bit, but I think it's the stuff further below that that you really don't want to remove. as long as you don't use a magnet you'll be fine.

good luck,

dave

Diesel911 · #10 10-30-2007, 03:25 AM

Don't forget your torque wrench this is one area that you really need one.

After you are done let us know if you it cured the problem!

ssorange · #11 10-30-2007, 12:40 PM

Quote:

Originally Posted by dave1980_300sd

yes, I got the tool at the dealer. it was about $45. I couldn't find it anywhere online much cheaper than that, and figured it was worth it to just be able to grab it at the dealer and do the job that much faster. still not too bad price wise... even including the tool it was barely over $50 total for me.

if you haven't already, it'd be a good idea to read up on delivery valve seal replacement in the archives... there are some parts of the delivery valves that you definitely don't want to remove. I used a pick and tried to disturb as little as possible when removing the copper washers (the o-rings come out with the part the special socket removes)... apparently going much deeper than the copper washer as far as removing things goes can cause big problems later on. the part immediately below the copper washer was hard not to disturb a bit, but I think it's the stuff further below that that you really don't want to remove. as long as you don't use a magnet you'll be fine.

good luck,

dave

Okay got it! Thanks everyone I'm heading to the dealer right now. I'll let you know how the repair goes.

@Dave: did you replace the Delivery Valve Springs since you had it apart. I'm thinking that it has 260k miles on it and the springs might need a refresh. What do you think?

Thanks all,
-John

rfdillon · #12 10-30-2007, 02:29 PM

If you have never replaced the tank strainer, you might want to drain the tank, take it out of there and look at it. I have had several friends whose cars would either die or wouldn't start when they got lower than 1/4 tank of diesel, as their strainers were completely sealed up with old algae. It reminded me of epoxy, it was that heavily encrusted.

dave1980_300sd · #13 10-30-2007, 09:02 PM

nope, I just reused the same springs, but now would certainly be the time to do it if you want. I can't imagine they're very expensive. I don't see how it could hurt to do them; my car had about 137,000 when I did the seals, so I didn't think to much about it, but with your mileage I'd figure might as well. this may be bad advice, though... maybe there's some reason not to change them? perhaps someone else will chime in.

good luck,

dave

ssorange · #14 11-29-2007, 12:48 AM

[QUOTE/]After you are done let us know if you it cured the problem![/QUOTE]

Hi guys, I would like to thank the folks on this board for helping out on this job, without whom I would have probably cost myself big bucks. The job went smoothly and has made a huge difference in how the engine runs. It now is much smoother and has more power.

I couldn't be happier about how this worked out and thanks again to all.

AFTER ACTION REPORT

The following contains a list of parts number of parts used and their prices. Also any notes of lessons learned during the job:

PARTS

Intake manifold to air filter connector (leaking so replaced) 601 094 03 91 $3.90
Air Filter cover attaching clip (lost two) 601 094 02 22 $1.70
Air Filter Box rubber isolators (worn out) 601 090 02 58 $1.40
Injector Pump Delivery Valve Seals 004 997 45 40 0.91/ea
Injector Pump Delivery Valve O-Rings 017 997 41 48 0.83/ea
Delivery valve springs (pre 08/88) 001 074 31 93 $4/ea
(08/88 and later)001 074 36 93 $2/ea

Delivery Valve Socket tool
617 589 01 09 00 $37

NOTES:

*Once I got all the parts together and completed all the research, it took me about 3 hours to complete the job.
*First and foremost read all the posts on this forum regarding this job. If you do so, it will be a relatively trouble free and inexpensive repair.
*Do not touch or rotate any part of the pump below the copper valve seals. Doing so will require the pump to be re-timed by an expert.
*Do not put this job off. Do it as soon as you notice any leakage at the injection pump. Keep in mind that if fuel is getting out, dirt is getting in. And this is not a place you want any dirt. Also the longer you wait the more deteriorated the rubber O-rings get. It is a very difficult place to clean out dirt and old rubber.
*The Delivery Valve Socket Tool is a must have.
*Clean the pump and surrounding areas that might get contacted during the job prior to starting. Remove the lock washers and clean again.
*Do one seal at a time leaving the other 4 closed.
*Get a good set of long nosed tweezers. I got mine from Longs Drugs. Use them to remove and install the seals and O-rings.
*I replaced the delivery valve springs since my pump had 250k miles on it. I would recommend this if you have a high mileage pump. The old springs were noticeably weaker.
*It takes a LONGGGGGG time for the fuel to get back to the injectors! Be patient. (Remember to let your starter motor cool down between extended use!)
*I crack open the fuel lines a little at the injectors and keep them open until there is a good stream of fuel w/o air bubbles. This seems to speed up the fuel arriving at the injectors. It gets easier once the engine will idle. I had to repeat this a couple of times for two of the injectors before all the air was out. It’s a lot faster than waiting for the system to self-bleed off the air.
*It is cheaper to buy the parts from someone other than the dealer (except for the socket). Some place like here at Finishline. The springs where dealer only.
*I just followed the shop manual and torqued the nuts down to 35 Nm. once. I didn't see any reason to torque then loosen then retorque as some others have suggested. Only time will tell.

lamont · #15 11-29-2007, 08:17 AM

This is the best thread I have read so far on this forum. Not because I need to do any of the above but because of the "after action report". I have read tons of old posts where guys will ask for help, others will offer solutions(usually with a smart ass comment thrown in) and then nothing. Searching the archives for a solution to a problem usually just gives you enough info to ask another question. It is refreshing that someone would take the time to follow up and and even create a list of the parts and tools for the job. Nice!

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