1987 300 TD funk

[groove]

I just bought a this 87 300td and it needs some help. It starts hard and idles even rougher-until it stalls which it does regularly...but it runs fine at 80 mph down the highway.I did a compression test and the engine is fine,and just completed a diesel purge with no improvement. Any suggestions on the next step to take?

[85chedeng300D]

my guess is idle speed too low and have you done valve adjustments? if not, this might be it. engine vibrates hard when cold if valve gap is too close.

[Zeitgeist]

Check the glow plugs to ensure they're all operating correctly. I'd also replace both the primary and secondary fuel filters. This engine has hydraulic lifters, so there's no need to adjust valves. You can also adjust the engine idle speed by adjusting the black ELR knob to a higher number--this knob resides in front of your fuse box, near the LF strut tower.

[groove]

Good suggestions.I adjusted the idle with minimal improvement. I should mention that this very rough idle and stalling happens all the time but it runs great at higher rpms. It also has a greasecar system installed.I have a feeling it might be an injector because of a strange rhythm to the idle and my local shop mentioned it as a possible problem. Anyone have any other ideas?

[Zeitgeist]

It's possible that the injector nozzles are bunged up, but I'd also suspect your injection pump delivery valves may need some new shims and o-rings...followed by Diesel Purge and an Italian tuneup. These engines are fairly simple, so there's just a small number of items that can go wrong to produce the symptoms you've described. A compression test would also be helpful, in order to rule out the truly nasty things that can contribute to your problems.

You could also help to isolate which cylinder is causing your idle problems by running the engine and cracking open the metal injector line at the top of each injector (14mm wrench). The engine should run rougher whenever a good cylinder's line is cracked--the results will be less noticeable when a bad cylinder's line is cracked.

[P.E.Haiges]

Groove,

If it goes "Down the highway at 80 MPH", there is nothing wrong with the filters!

First do the easiest thing, a resistance check on the GP. They should all read from 0.6 to 1.0 ohm. Any GP reading higher should be replaced. Use the search function to find how to do the GP resistance test.

P E H

[groove]

Thanks for all the good suggestions.I ran a diesel purge-no change,cracked the injectors and they all seem to react the same way -making the engine start to sputter.Checked all my fuel lines and tightened clamps,adjusted idle,changed fuel filters and finally had a compression test done which came out fine,no change in the rough idle and stalling under 1500 rpms.Car is undriveable at this point....I noticed some leakage at the seat of the injector lines where the splined bolt meets the IP pump,could this be an indication of bad pressure valve seals? thanks!

[Zeitgeist]

Yes, I'd definitely R&R the delivery valve shims and o-rings at this point.

[nuckingfuts]

Originally Posted by Zeitgeist

Yes, I'd definitely R&R the delivery valve shims and o-rings at this point.

Do you know where to find a shim and o-ring kit or is it easier to just buy them all seperate? Also, what size tire/wheel do you have on your car, those look GOOD.

[Zeitgeist]

Originally Posted by nuckingfuts

Do you know where to find a shim and o-ring kit or is it easier to just buy them all seperate? Also, what size tire/wheel do you have on your car, those look GOOD.

You buy them separately (six of each), and any of the online WorldPac vendors (like Fastlane) can get them for you. They're really cheap. You also need a splined socket wrench to remove the delivery valve holder.



The wheels/tires are from a 2006 C230 Kompressor.
Fronts are 225/45 R17
Rears are 245/40 R17