Won't start after changing fuel filter - PeachParts Mercedes-Benz Forum

gcoffelt · #1 01-24-2008, 07:47 PM

Changed out the fuel filter the other day, then went to use primer pump, but the pump was cracked on the bottom and fuel shot out with every pump. Ordered a new old-model pump (as I am using bio and soon wvo), just put it on, went through the procedure, and it still will not start.

I noticed the fuel filter I put on is slightly more wide than the previous one, could this all just be because of an incorrect fuel filter was sent to me? That's the only thing I can think of...

estod · #2 01-24-2008, 08:54 PM

You may also have an old O-ring on the secondary filter that is now sucking air.

You also may not have pumped enough. If you didn't fill the filter with fuel before you put it on (many people use Marvel Mystery Oil or ATF for a cleaning shot at the injectors), you have to pump quite a bit before you fill the filter and all the lines.

gcoffelt · #3 01-24-2008, 10:03 PM

Quote:

Originally Posted by MTUpower

then turn the engine over until fuel comes out each line at the injector. .

Are you meaning to turn the key as if I'm going to start it, or stop at the point where it makes a clicking noise just before it goes to start?

gcoffelt · #4 01-24-2008, 10:36 PM

Okay, now to make sure, the nut you mean is the one on top of the injectors, where the metal injector line connects with?

barry123400 · #5 01-24-2008, 10:57 PM

Yes.

turbobenz · #6 01-24-2008, 11:30 PM

It takes ALOT of cranking to get all the volume of the fuel filter filled with oil. Thats why they always say that you should either fill the filter with diesel fuel or vegetable oil before you put it back on. The hand primer will work, but it takes forever. Just keep trying.

gcoffelt · #7 01-24-2008, 11:46 PM

I've pumped and pumped on that thing for quite some time. At certain points the pressure on it varied, and I could hear the sound of air moving about somewhere.

I don't have the right tools to crack open the nut on the injector, I guess I have to wait until tomorrow. Another thing I was told to try is remove the fuel line that goes to the injection pump, and set that in an empty bottle and pump until only fuel spurts out. Problem here is, the previous owner used lines that I heard are meant for RC cars, a flimsy rubber material (the first time I took it on a highway a return line bursted from the heat.) I have since replaced those return lines, but never paid attention to that line going from fuel filter to injection pump. The injection pump side of the line will not pop off, and is probably melted to it, a problem I had while replacing the return lines.

spugeddy · #8 01-25-2008, 08:48 AM

I don't think anyone mentioned it.... did you check all of your vacuum lines? with an oil filter change they get crunked up, and you may have leaned on one when doing the secondary filter... did you fill the primary up with diesel before spinning it on?

LUVMBDiesels · #9 01-25-2008, 10:02 AM

Ok, from what I hear you have multiple issues.

First let's get our terms right.

Primary filter = the clear or frosted plastic filter inline with the fuel line coming from the tank

Secondary filter = the oil filter looking thing attached to the metal bracket

Return lines = the thin cloth wrapped lines that go from the injectors back to that metal bracket thing. The fuel then goes through the 'cigar hose' back to the tank.

Which filter did you replace? We are assuming you replaced both primary and secondary filters. Did you tighten the bolt on top of the secondary filter enough? It should be tight enough that you cannot turn the filter body by hand.

You have the wrong fuel lines. If one melted to the IP it is probably going to be leaking air

You need to pump the primer until you hear air escaping from the system. it can take 40 -50 pumps if you do not fill the secondary filter.

If you are getting air into the system you will probably have to crack open the injector lines at the fuel injector. you can also crank the car over until you purge the air, but that can take a while and will be useless if more air is getting in via a cracked hose or as was said in a previous post you have two o rings on the secondary filter.

I would replace any bad fuel lines. Then I would remove the secondary filter, make sure that there is only one o ring, fill it with 'Diesel Kleen' or automatic transmission fluid. then put it back and tighten it. Then I would pump the primer until you hear the air escaping. Then I would crank the engine over for 30-40 seconds then give the starter a rest for a minute and repeat until the car starts.

tobybul · #10 01-25-2008, 11:34 AM

Read about air in the IP!!! Do a search or check my post on this....

NH82W123 · #11 01-25-2008, 11:51 AM

gcoffelt,

Where did you get your replacement (secondary) filter? When I first got my 82 300D, I attempted to replace the PO’s NAPA filter with a Mann model that I bought from Fastlane. The filter that arrived, matched to my year and model, was, just as you described, “slightly more wide than the previous one,” and no amount of primer pumping or engine cranking would start the car. I ended up reinstalling the NAPA one and had my indy source a new filter when I had it in the shop the next time. Phil was really nice about the problem, even sent me a new Bosch filter for free, but there was something odd about my set-up that didn’t take the “standard” filter size. First time he’d ever seen anything like it. Maybe you have an odd filter set-up too?

Charlie

gcoffelt · #12 01-25-2008, 05:05 PM

Quote:

Originally Posted by LUVMBDiesels

Which filter did you replace? We are assuming you replaced both primary and secondary filters. Did you tighten the bolt on top of the secondary filter enough? It should be tight enough that you cannot turn the filter body by hand.

You have the wrong fuel lines. If one melted to the IP it is probably going to be leaking air

You need to pump the primer until you hear air escaping from the system. it can take 40 -50 pumps if you do not fill the secondary filter.

If you are getting air into the system you will probably have to crack open the injector lines at the fuel injector. you can also crank the car over until you purge the air, but that can take a while and will be useless if more air is getting in via a cracked hose or as was said in a previous post you have two o rings on the secondary filter.

I would replace any bad fuel lines. Then I would remove the secondary filter, make sure that there is only one o ring, fill it with 'Diesel Kleen' or automatic transmission fluid. then put it back and tighten it. Then I would pump the primer until you hear the air escaping. Then I would crank the engine over for 30-40 seconds then give the starter a rest for a minute and repeat until the car starts.

I replaced the inline filter a week or so before this happened, so it was running fine with that on. And I had no idea there were o-rings for that, I just bought 3, and put one on straight as it was. I assumed it was good to go as is- is there supposed to be an o-ring on either side of it where it connects to the fuel line? Because it certainly didn't come with those.

It was the secondary filter I replaced that started the problem. And no, I didn't remember to fill it with diesel at first, but realized the error seconds after starting it up... Lesson learned I suppose.

And is the fuel line going from secondary filter to IP supposed to be the braided-type hose used for the return lines? There I have some clear blue rubbery-feeling line, like the ones put on the return lines when I bought the car (From one of those people who think they are being innovative and original, but really, they're just making a bigger mess of things by not doing what is intended for the vehicle.)

On top of all this, when I try turning the engine over it appears the battery is dying. The engine will only try for a few seconds then it will get slower, and slower, and slower. Eh...

gcoffelt · #13 01-25-2008, 05:13 PM

Quote:

Originally Posted by NH82W123

gcoffelt,

[COLOR=black][FONT=Verdana]Where did you get your replacement (secondary) filter?

Charlie

I ordered it from ************************ ... I have replaced that secondary fuel filter a few times since I have had the car, and have never had any problems. I don't believe I have ordered that part from performance products, though. It was always whatever I can get my hands on, like fram from walmart or one from carquest, or of the sorts. I didn't think it made any difference, but that's coming from somebody who has absolutely no experience with cars or even turning wrenches on something more than a bike.

That would be wonderful if all it were is an incorrect fuel filter, but I'm seldom so lucky.

LilTimmy · #14 01-25-2008, 07:00 PM

I'd replace ALL the fuel lines in the engine compartment with good modern rubber. Your local import parts place should have all of them on hand. Take off the secondary filter and fill it up, charge the battery, and have another go.

gcoffelt · #15 01-25-2008, 09:01 PM

Thanks a lot everyone. I don't know where I would be without this forum, I most likely would have given up on fixing up this old diesel months ago and gone back to a car that takes the $3 a gallon rip off that gasoline is (though I guess regular diesel is almost $4 a gallon here now, it's okay I'm on inexpensive homemade bio.)

Thanks again!