I've got a 76 300D- not very well maintained by it's previous owner, but I'm trying to make it functional.

Here's the sitch: Car was suffering from a huge loss of power, which I assumed to be fuel filters because I just started running it on B100. We changed all filters, fuel and air, adjusted the valves and ran diesel purge through it. Also changed a leaky fuel line at the tank. Started it up and it ran better, but still won't go over 30mph up even slight hills. Took a look and it appears to be drawing air into the fuel lines (inline filter won't fill up) and from testing it out, we determined that it's drawing in air before the inline filter. All lines before the filter appear to be solid and tightened and there are no fuel leaks under the car. What's going on??

Probably not relevant, but I'm told car has a vacuum diaphram leak, which is responsible for stiff breaks and smoking as well.

Thanks so much...this forum is keeping me sane.

Run to the nearest auto parts store (as fast as you can run in a leaky 300D) and buy 4ft of 1/8 inch i.d. fuel line and 3ft of 1/4 in i.d. fuel line. Replace ALL of the braided lines under the hood (send, main reutrn, injector returns). This will take care of 99% of your air-in-fuel problems. When those braided lines are cracked and sucking air, they will look just as clean and dry as anything else. Start with the send line (between the metal line and the in-line pre-filter).

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1983 300SD
Rusty, Loud and Proud

Oh, and I forgot: If you haven't installed a new-style bosch primer/lift pump, now's the time to do so.

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1983 300SD
Rusty, Loud and Proud

The clear filter is always going to have air in it. It's fine as long as there is only one large stationary bubble and not a stream of bubbles moving through it.

the steel line that goes back to the tank can devolope leaks. air will become a big problem before you will see a fuel leak, because it is easier to suck air in than diesel to leak out.

I did a temp fix by running 5/16 fuel line from the tank to the inline filter. no issues in over a year,i replaced iot w/ HIH for veggy.

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1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

Can't do that on this car. The 115 300D has a disk type primer pump attached to the main fuel filter. It generally works pretty well. (Better than the old style primer pump on 123's). No need to update.

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Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



TRUMP .......... WHITEHOUSE
HILLARY .........JAILHOUSE
BERNIE .......... NUTHOUSE
0BAMA .......... OUTHOUSE

Thanks, I didn't realize!

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1983 300SD
Rusty, Loud and Proud

There was a stream of bubbles moving through the prefilter, which I determined was coming from the send line by bypassing the line with a jar of fuel and a new hose. I replaced all of the hoses but the return injection (i know, i know). Not sure which one did it, but it's all good now. One was stiff and cracked once I got it off, one on the return line had bubbling.

power (well, for a poorly maintained 76 anyway) is back.

Thanks!

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1976 300D 217k...an old car needin some love. (GONE OFF TO RUSTY CAR HEAVEN)

1982 240D probably something like 190,000 miles...was Old Yeller, but I changed the name to Buttercup