So my 70' 220D has progressively gotten worse at starting up and eventually wouldnt turn over at all. I thought it was perhaps a leak coming from one of the fuel fittings next to the fuel primer pump, so after awhile of the car sitting I finally was able to replace some o-rings and washers, recharged the battery, and the car started right up but idled really high. I only let it run for about 20 seconds, went and got dressed to take it out, come back and now its back to the same problem, wont turn over at all.

Im guessing this is fuel related since my glow plugs are brand new and testing okay with the meter. Where do I start diagnosing?

Ive had this problem before and had it towed to a mechanic, he pumped the hand primer pump, jumped the battery, and it started up just fine and ran very well. So he claims the hand pump just needed to be pumped, but Ive tried pumping many times but still the engine wont turn over.

Im thinking its either dirt in the fuel system since the leak I had previously had was pretty bad and there seemed to be alot of gunk where the leak had been telling me dirt got in. Or perhaps fuel pump related?

Thanks for any help!

Some thoughts:

It sounds like there isn't enough fuel pressure. You might want to start by considering the fuel filters ..... I believe you have three of them at least on W123's there are three .... one in the tank, one plastic inline, and the main canister. If your fuel filters are new/ok then maybe your fuel pump itself is worn and not producing enough pressure. When you pump it by hand and it starts fine that seems to suggest that the mechanical pump mounted on the side of the injection pump is weak or leaking pressure when it sits. Another possiblity is that if when it started last that it idled high or uncontrollably ...... perhaps you inadvertantly filled up with gasoline? It happens. If it is gasoline in your fuel, you'd have to drain the tank and replace all the fuel filters and use the hand pump to clear the injection pump of gasoline. After doing so it should start back up. Good Luck.

David Roseman
Long Beach, Ca

thanks for the advice. i dont think i accidentally put in gasoline because i actually leaked alot of fuel into a cup while replacing the the o-rings and washers i mentioned, and it smells/looks like good old diesel fuel. all of the fuel filters are fresh and new as well.

i also replaced all the fuses just a few minutes ago for good measure. also loosened the four locking nuts on the fuel injectors to bleed the air out and make sure all four were getting fuel, which they are, so that checks out.

Im wondering if the battery might be out or if the alternator isnt charging the battery. a few days before i started having trouble turning over, i drove through a pretty high puddle of water while it was raining and immediately got a bad rubber-burning smell coming from the engine bay. im wondering if i fried the alternator or something?

if the battery isnt supplying enough juice to the high-demanding glow plugs then might explain why its not turning over? any other suggestions?

Just for clarity, would you please define what you mean by 'turning over'? Typically when the engine does not 'turn over', what is meant is that the starter won't turn the engine because of an electrical issue or the engine is frozen. On the other hand if the engine does not fire when spun, that is because of fuel, compression, or glow-plug issues. Of course both sets of issues can concurrently exist.

__________________
1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150

the starter engages and spins the crank but the engine wont fire. sorry for using the wrong term, makes more sense now.

If you have the old white topped screw down primer pump, these are notorious for leaking and have been superceded by a newer spring loaded pump that does not leak. Some people have temporarily fixed their leaky old pumps by stretching a balloon over the pump to stop air from getting in. It would be a simple method to diagnose whether your pump is the source of the air leak or not.

__________________
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

i should have mentioned i have replaced the older style hand pump with the new bosch one.

can anyone confirm that the two fuses that are inside the two little black boxes mounted on the driver-sider fender in the engine bay, are indeed supposed to be 8w fuses or larger? I think one of them is for the glow plugs?


EDIT: FIXED! BAD BATTERY, WASNT GETTING PROPER POWER TO THE GLOW PLUGS.