Hard starting last few days, not just cold. (fuel issue?) - PeachParts Mercedes-Benz Forum

zykalaz · #1 11-17-2011, 10:50 AM

So my car had been working great perfectly starting even in the mornings (low 50s) with little to no glow plug time.

Then I went to goto work one night (mid to upper 50s) and it just did not want to start.

I let the glow plugs go 2 cycles and still did not want to start
Luckily I have a nice battery that is up to the abuse i put it through.

The entire time the car wanted to turn over you could hear it about ready too but nothing. Then I tried again and it kicked right on, little slow at first seemed like it was going to stall so i gave the pedal a slight press. after about 15 seconds all was fine. It did smoke heavily at start up for about 5 seconds or so could not see the color as it was dark and the windows were fogged up but could tell there was a bunch. I think it may have been white colored.

Did the same thing the next morning on me. Well I got to working on it this morning.

It sounded like a fuel issue to me. I looked at the pre filter and it was about half fuel and half air. which seemed a tad odd to me. I opened the primer pump and attempted to pump it (i know this is broken it normally spits fuel out at me) and I got nothing with it, it was easy to press and no fuel came out.

I took the main fuel filter off and it wasn't quite as full as i remember when i changed it out last. I emptied it out looked like good clean fuel. I filled it back up. I tried to turn the car on and it turned on immediately with almost no glow plug time.

The air in the prefilter was gona after a about a minute except just a touch. When it started there was next to no smoke. However while I let it idle I walked around the car and there was a splatter zone behind the exhaust pipe that was black in color 1 foot wide and about 3 feet long. Thousands of little black spots. They smeared when I brushed my fingers over them but they were so close to dry I couldn't tell if it was oil or not.

I opened up my air filter cause I know in the past my blow by has been spitting oil into my filter housing and clogging air filters like crazy. new breather tube fixed that though and still no issue really just a slight residue on the down spout.

SO i figure it may be a small leak in the fuel system (probably the priming pump) and it just took a while to get the fuel into the engine cause of the air in the lines/pre filter?

So what just happened? and what did it spit out the tail pipe?

If it was oil I would think it would have been smoking, wouldn't it?

macdoe · #2 11-17-2011, 05:44 PM

Same thing happened to her 85 TD a couple years ago. I think it was really cold that day....and we had it running all morning for highway driving. I never shut it off at all that day cause it was like -40 celcius. I had been running a fuel additive and noticed it mid afternoon when refilling with diesel. It was a fine tar like substance all over the back of the hatch. I theorized that maybe it cleared out the exhaust, but I don't know??

I have a similar story to yours in that this car had always started great until the end part of last winter and now since this recent cold weather has set in it has become even worse. Last winter I think we were having some sort of condensation in the fuel cause I was having to use a torch on the hard lines to get it to go when really cold. I theorized this time that the bit of condensation in the lines was causing the fuel to freeze or gel up abit. Last night we installed a new set of fuel filters and ran the Lubro Moly diesel purge through it. Went to start it this morning and she is right back to starting perfectly again.
This is the first time using that diesel purge and the results were amazing. The engine sounded great while running on it. It was so quiet you could hardly tell it was a diesel. I have read about other users running it but could not find it until we went to NAPA yesterday and found some. Best 15 bucks ever spent. I will now run this stuff through every winter considering the results. I have always kinda thought that additives like this were a rip off, but it really did make a noticeable difference to say the least. Thought it was just a quick fix for something that otherwise should be corrected at a mechanical level. It did everything as advertised on the can....wow. It was just too easy to be true....not used to it happening that way without a bunch of hard work.
I guess to be scientific we should note the additional variable to the regiment was that the fuel filters were changed at the same time. They may have been key to the results we got???.
In hindsight... this forum has told us to keep on top of regular fuel filter changes and diesel purge...something I have not been real diligent about which may have been the problem right there. I tried to see if there was water in the old filter but could not see any which does'nt mean it was'nt there.
I now wonder exactly what the diesel purge does ?

vstech · #3 11-17-2011, 07:20 PM

was the car parked nose up or nose down?

how long was it parked before you had problems starting it?

get that primer changed!

kerry · #4 11-17-2011, 09:13 PM

I wouldn't exclude the glowplugs without some diagnostics.

Codifex Maximus · #5 11-18-2011, 01:02 AM

Quote:

Originally Posted by vstech

was the car parked nose up or nose down?

how long was it parked before you had problems starting it?

get that primer changed!

X2 on the primer pump.

Then look at the glow plug timer fuse and then the glow plugs.

t walgamuth · #6 11-18-2011, 08:25 AM

Classic glow plug symptoms.

zykalaz · #7 11-18-2011, 09:01 AM

I pretty sure its not the glow plugs already tested them and the wires to them , I'm pretty sure its not enough fuel getting to the engine at first due to air getting in somewhere.

The car was parked nose up the first time, and level or slightly nose down the second time. The car sits for about 12 hours.

I just got home from work now and it was level or slightly nose down again at work, and gave me the same issue.

Before I tried starting it for work last night and this morning, I checked the pre filter and was again full of air both times. After 20 seconds of turning It kicked right on as the air disappeared out of the pre filter.

So looks like the Primer is causing an issue now, or if not it is the first thing i'm going to replace to see if it works.

There is a chance I will be running some Bio, So i should just stick with the old version as the new version is not Bio friendly yes?

I have not run diesel purge through this car yet. I don't drive it but 40 miles a week maybe. What would be the best way to do it if I don't drive it a lot.

bd1308 · #8 11-18-2011, 09:43 AM

The "old" primer pump supposedly isnt available from Bosch anymore. Dont know if this is temporary or permanent, I suspect that its permanent.

My primer pump is the white "old" one, and I think it leaks air.

charmalu · #9 11-18-2011, 12:21 PM

Did you phisically pull the GP`s and put power to them to see how hot the glowing ends got? or just test with a volt meter? the tips should get white hot. carefull, they will burn you.

Replace the old leaky Primer Pump with the new style black one, the new style is so much better than the old style. replace the rubber fuel lines also.

Replace the filters with new one`s, and don`t fill them with fuel from a fuel can, good way to introduce air/water/dirt into your clean filter. fill it with ATF from a clean bottle or Diesel Purge.

Only drive it 40 miles a week? how about getting out on (what is that through Phoenix, I-10?) and get it good and hot, and give it a good Itilian tune up to blow out the Cob Webbs.

The black stuff you saw on the ground was soot and maybe some moisture blowing out the tail pipe. If it had any oil to it, it wouldn`t be dry.

What model MB are we working on here?

fill out your signature.

Charlie

piccolovic · #10 11-18-2011, 12:51 PM

You can generally take apart the primer pumps and replace the O-Rings, which will stop the leaks/sucking air. While you are there, it would also be a good time to replace the power steering hose, as the primer pump is in the way of the power steering hose. When I first got my '76 240D, it was blowing out the power steering fluid as fast as it could be poured in. Not wanting to spend $600 to replace a burned-up power steering pump, I took the car to a mechanic to have the hose replaced, as a priority. During that time, they saw that the o-rings had all disintegrated, and they replaced them while putting the primer pumpt back together. Half of my fuel leaks disappeared then. Then I only had to replace return lines and o-rings on the injectors.

zykalaz · #11 11-19-2011, 11:42 PM

I thought I had filled out my sig turns out it was just the info page where I Listed what was in my garage.

I took out the glow plugs and hooked them up 4 got really hot and the 5th got just slightly less hot.

So I don't think it is the glow plugs. So waiting for the primer pump to arrive.

I backed the car in today so it was nose down, and it started almost immediately like it was before. Also the pre filter had almost no air in it at that time.

Thanks again

t walgamuth · #12 11-20-2011, 05:17 AM

You need to replace the slightly less hot one.

zykalaz · #13 11-27-2011, 02:36 AM

I replaced the primer pump and it started up like it used to, I then replaced all the glow plugs after cleaning out the holes and it starts like a champ now.

I did however push the hose near the firewall out of the way to get to the last glow plug and forgot to put it back which made the throttle act sticky which gave me a good scare the first time i started it up.