Hi I have an 1985 300D Turbo. I am experiencing a intermittent fuel problem I believe. The problem occured the other day and it did the samething a couple of months ago (first time the problem just went away on its own). I was driving on the highway and the car all of a sudden just lost power and stalled. I pulled over to the shoulder of the road. The car would not start but, after about a 15 min. wait the car would start (not easily though) and would get up to around 20 to 40 mph and would start bucking and stall out again after about a one to three mile run. I would have to wait about another 15 min. before the car would start and go through the cycle again. A couple of days prior to this the car would start to loose power when going up an hill and just did not perform right. I did a diesel purge and replaced all filters and the car ran fine for about two days when the problem occured but much worse. I did have an vacuum leak that prevented the car from shutting off. It was in the connector for the EGR valve. After I repaired the leak when I started the car up light blueish smoke was coming out of the engine. I isolated the EGR valve and the smoke went away and I did not reconnect the valve. Right now the car seems to be running OK. I have not venture to far from the house because I had to have the towed. My question is when I was investigating the vacuum leak I found the pressure releif vavle (I believe thats what it is called its the white valve thats on top of the IP above the shut off vavle) had oil on the bottom connector that is the vent line going into the cabin. Does that mean the diaphragm in the valve is bad? Is there a test that I can perform on the valve to check it? Also if the valve is bad could it cause the above problem?
Thank You

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Mike

That white valve is the transmission vacuum valve. Probably doesn't have anything to do with what you're experiencing, and neither does the EGR or vacuum system for that matter. If the car goes through the gears alright then it's not the issue. You could check it with a Mityvac or similar to be sure but I don't think your power and engine function would be affected by a vacuum problem. Most likely you have cracked rubber and/or plastic fuel lines that are giving way and allowing air into the fuel system, or the strainer in the fuel tank is clogged wth fungus or gunk accumulated throughout its life which is only now being loosened by the new fuel being bought and sold. There may be a possibility of the lift pump which is mounted to the side of the injection pump getting weak. Definitely a fuel delivery problem however, and fairly common as I am experiencing somewhat similar issues, but my car hasn't stalled out yet. Probably just a restriction in the fuel system somewhere.

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

Thanks for the clarification.

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Mike

If you have done the filters about the only thing left in the system is the inlet strainer in the tank. If you have an air compressor try this.

Take the filler cap off the tank, disconnect the fuel line from the tank at the primary filter, blow air back through the line into the tank, get someone to listen at the tank filler to hear if the air is really coming through or just barely bubbling. If it is really coming through you may have either blown off what ever was blocking the strainer or the falter may be clean.

I have also put air pressure onto the filler neck and blown fuel towards the engine. This way you can see if you are getting a full flow. Don't get carries away and seal the hose into the tank. Just wrap a rag around it. You only need a pound of pressure or so.

Problem solved. I removed the fuel strainer in the tank and it was covered in slim.

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Mike

I would follow up with some bio stat to help get the fungus issue in check. I would also pick up a couple of the small secondary filters to keep in the car as you will probably need to replace them a time or two in the next couple thousand miles. Keep the car topped up as often as possible right now and for the next month or two.

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87 TDT 286k
87 SDL 195k
83 SD 202k
83 SD 201k
83 D 286k
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"Danger takes many forms"

Will Do Thanks

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Mike