I recently purchased a 1984 300td w/ the hopes of saving this car from its
otherwise doomed life. The previous owner had been experimenting w/ WVO and Bio Diesel in a single tank system. He stated that while on a trip he parked the car to eat and when he came back out he could not get the car to start....he finally got it started however it would not idle.

I drove the car 100 miles home...it runs great at highway speeds, but as your RPMs drop to around 1000 it starts running very rough....if you let off the accelerator the engine will die. I did notice on the drive that after letting off the accelerator it would take awhile for rpms to drop off like something was hanging up....checked linkages and all good.

The problem its not in the tank. I have changed fuel filters, and swapped out the injectors and lift pump, but the car still will not idle.

I still need to adjust the valves, but if that doesn't help I am out of ideas. I am afraid that the problem may be in the injection pump...I am needing some guidance so I can get this car on the road and give her the life she deserves.

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1981 240D

I agree that the problem is likely in the injection pump. I'd do some pressure testing on the lift pump first however before condemning the IP. WVO is known to cause IP problems. Can't imagine maladjusted valves causing that symptom.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

A good flushing out of the injection pump with a solvent might be worthwhile attempting. Also closing off the relief valve line from the pump to see if it will idle. Suspect perhaps a lot of garbage might be present. to establish what cylinder or cylinders are not firing if that is the issue..

Read the milli volts from the glow plug harness with the engine running. The glow plug that has no milli volts will be the cylinder or cylinders that are not functional. Loosening fuel lines to establish above 1000 rpm is probably just too hard to tell properly.

Ah well I have been where you are now. Not fun. Some Qs:

How long had the owner been doing these brilliant experiments?

What is in the tank now?

What does the exhaust look like, when the rpms get down low enough for the rough running symptoms?

How many miles on the motor?

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

Fuel Pressure Relief/Overflow Valve Thread

Fuel pressure relief valve adjustment

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84 300D, 82 Volvo 244Gl Diesel

So I have decided the IP is the culprit....I have an extra one off my parts car that I plan on installing.

This will be my first experience doing an IP R&R...are there any special tools I will need to do this?

Words of wisdom and/or links to a DIY write-up on this would be great!

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1981 240D

Whoa, before you go a swapping the IP try running a couple cans of Diesel Purge straight through the fuel system. You probably have some gunk built up in the pump. Diesel purge will clean it out. You may not need another pump. A diesel purge is much easier than swapping IPs. It's worth a shot.

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Getting the IP off is not an easy job on a 617. Ive done it a few times on my 616s and that was a bear each time. 617s are harder because of less room. Good luck saving another WVO daydream/nightmare.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Diesel Injection:
Diesel Injection:






.

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1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

You have done a compression check on this engine I hope?

For tools and stuff. If you have the Port for it you can use the Fuel Injection Pump Timing/Locking Pin; but, you would need to buy or borrow one.

Fuel Injection Pump Removal with the Oil Filter still on 617.952
Fuel Injection Pump Removal with the Oil Filter still on 617.952

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84 300D, 82 Volvo 244Gl Diesel