Won't start after changing primer pump
 

Howdy,
I have a recently acquired 85 300td. One of the first issues I noticed was a leaky primer pump, so I ordered a new one along with some new return line tubing to replaced some saturated lines I noticed. As I was replacing those yesterday, I also noticed the pre-filter was dirty again. Full of black particulate even though it and the main fuel filter were changed not long ago. As I pulled on the fuel line going to the prefilter air bubbles entered to the bottom, this was repeatable each time I manipulated that particular line. So, I also replaced that line and prefilter. As I pumped the primer it did not seem to fill up the pre filter but was not sure if it was supposed to. Now it won't start. I read about how to bleed the fuel injector lines, so I have done this, but the prefilter is still not filling. I'm pretty sure I did everything correct, it's all pretty simple stuff. There was also a big cloud of white smoke that came out after the longest attempt to start the engine.
Any ideas on what I am missing or what I can try?
Thanks,
Zack

The dirty prefilter indicates a blocked tank filter.

Normally if you pump with the primer pump, the prefilter should fill up with fuel. Then you should pump further until you hear the pressure relief valve of the IP opening (buzzing sound). You can start the engine at that point.

If your prefilter doesn't fill with fuel, there is no fuel in the tank or the tank filter is blocked.

Ok, so I will look into dealing with that. But is it normal to go from starting up fine, to not starting at all so abrubtly from this issue? I was certain it was a result of something that occured as a result of what I did yesterday.
Thanks for the response, I had actually read about changing the tank filter and found an extra one in my spare tire compartment the other day. I guess it was not a coincidence.

Zack

You should do as you said and loosen the Fuel Injection Lines at the Injectors.

If Air gets In the Fuel Injection Lines when you crank the Engine you compress that Air and it moves very little down the Line. Loosening the Fuel Injection Line Nuts at the Injectors allows the Air an easy escape.

If those Black particles continue to show up in the Primary/Plastic Filter it can be an indication that something is growing inside of your Fuel Tank.

Also if your Fuel has some crud/contamination in it (sometimes you get it right from the Pump at the Station) I have seen new Filters plug up in a matter of minutes.

Hunter went through a lot of time to organize the problems and troubleshooting stuff of the most valid Threads into groups making it easier to search.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

I have read, that some people don't know how to use the new primer pump....the new style black one...you push down on it and it springs back up...then you repeat...some people have mistakenly tried to twist and pump.....if you get no fuel in the pre filter...you can also try to remove the gas cap and then see if you can....it could be a blocked tank vent...

Just changing the primer pump wouldn't cause problems, unless the primer pump doesn't seal properly on the lift pump. You did use the copper crush ring?

Other possibility is that you changed the fuel and return line and the tank is not full, but it is not very likely.

You could also check the rubber fuel lines near the tank, maybe they collapsed (after trying to pump fuel with a clogged tank filter), so that you only pump up air.

If you have a jerrycan of fresh diesel, you can put the fuel line into that jerrycan and pump with primer pump. If the prefilter fills with fuel and you can hear the pressure relief valve of the IP opening, than you know that there is a problem with the fuel supply from the tank and that is usually a clogged tank filter.

You also might have accidentally put the pre-filter on backwards.

Ok, I hope to not miss responding to anyone on here, but taking in a lot of info from forums and those kind enough to respond to my account.

I used the copper ring with the primer pump, but wasn't sure if I was supposed to take one off from the old one. It looked like something copper was on there already, and I tried gently to see if it would come loose. Removing an old one was not part of the directions I was following, and what I was seeing did not want to free up easily. So I did not push it. With the configuration of my fuel lines I don't think a backwards prefilter is possible. I did not remove the return line. The new primer pump is the old style. I did loosen the injector lines and bleed them of air till I saw fuel. I also filled the prefilter and fuel line with diesel and it almost started, but as it pulled fuel from the prefilter it did not refill.

I siphoned some fuel from the tank and It had a lot of the black garbage in it. I also blew back with air from the fuel feed line and it seemed to resist more at first, then blew right through as if it cleared something there. So I feel like that is my problem. gonna work on the tank filter/screen today, but see a lot of different opinions on whether I need to drop the tank to flush or whether I can do it on the car.
Thanks again,
Zack

Tank screen did not seem that dirty. I have not dealt with the tank yet, still sitting on that decision. But everytime I prime it there is a reclogging of the supply line indicated by a difficulty to prime and pass air through to tank.

This is an early version on the lift pump, but you can see how the copper washer sits flush with the top of the pump....you have to use a screw driver or pick to remove the copper washer...

Regards to the tank, remove the first aid box behind the rear seat and remove the fuel sender....you can use this large hole to put a water hose in to flush the gunk out of the tank through the fuel tank screen hole....let it fully dry or use a hair drier/heat gun to dry the tank before you add more fuel.

It is possible the gunk is coming from the steel fuel lines themselves, they my be rusted out...

http://www.peachparts.com/shopforum/...13174295_o.jpg

How much fuel is in your tank? so 300td, is it a wagon or a sedan? TD is for a wagon. a wagon tank is 18 gallons and a 300D is 21 gallons. so @1/2 a tank you are looking @ 10 gallons in the sedan.

You need to get as much fuel out as you can before removing the tank screen. the screen is about 3' tall, and depending how plugged up it is, you will have that many inches of fuel in the tank.

I got a Diesel bath removing one of these on a 240D. removed the fuel line from the tank to the hard line to the engine, and let it drain into a bucket. used a pair of 6" Vice grips to squeeze off the hose when I dumped the bucket. then let it dribble and drain all night.

Next morning I used a large drain pan about 3ft x 2ft, and pulled the screen. got a good surprise with the amount of fuel still in there. :eek: splashed off the Differential, axle and me, and some on the ground. have rags and some oil soak stuff handy, old cloths and safety Goggles.

next time I will use a large funnel and hose to the pan when I drop the screen.

The screen is cleanable and reuseable.

I personally wouldn`t try to clean the tank in the car, I would remove it.

Really not a big deal to remove the tank. the hardest part of removing the tank, is thinking about removing the tank.

Charlie

Sorry did not read all the thread. It sounds like bacteria in the tank to me. Before trying to clean the tank of prefilter I'd treat the tank with biocide. After biocide treatment the bacteria is broken down and should flow through the filters and the engine should run fine.

I've never cleaned a tank or prefilter yet except for biocide, and I've had a lot of diesels almost all old and high mileage.

Could be not sealing at the copper washers if you have one on top of another. So you replaced an old style primer pump with another old style pump? How do you know the replacement is any good? You could also have blockage in your supply line between the tank and IP, especially if it ran wvo in the tank. Or you could have a pinhole leak in the supply line due to rust, usually occurs beneath the clamps.

I found a thread with someone who was having similar problems after replacing the primer pump and filter. He took it to a mechanic and the only thing that worked was to put the old primer pump back on. After trying everything else reccomended, I did that........and it worked. I don't believe that is the one thing that it could have been, but it seems to be runnning just as good as before. (primer pump still leaking of course) It was a complete and instant fix to the non-starting, lack of fuel pressure problem.
Go figure. I'm still gonna flush out the tank and have done a fair amount of fuel line replacement. It can't hurt right. Should save on filters down the road, it can't be good to have all that debris floating around in there. Hopefully **************.com will send me another pump. And I did have 2 copper rings on there. But the new pump still didnt work with only one.

Make sure you get this primer pump....don't replace it with another old style one....

http://www.greeneyeautoparts.com/eba...0000908850.jpg