I've got a 1984 190D that won't start. It turns over very strong, so it is not the starter or the battery that's the problem. It simply will not catch and fire off. I am not well-versed on the operation of the diesel engine, so I went to the library to learn - what I've discovered is that I don't think it's a particularly good idea for me to attempt the repair myself! Although I'm a female, I am quite mechanically inclined, so I'd like to have a go at figuring it out anyway. What I've got so far is this: obviously the problem is fuel or compression oriented (!). I pulled the main fuel filter and found much dirt in it, so I replaced it. I was getting a lot of fuel into the filter, so I do not think it's the fuel pump. As well, I was getting lots of fuel coming out of the filter, but since it was so dirty, I replaced it anyway. The library book said that, "The smallest particulate of dirt can clog the nozzle of an injector.."
Since there was so much dirt in the fuel filter, it is conceivable that a small particulate could have passed through and subsequently clogged a nozzle, right? On another forum I went to, one gentleman said that a clogged injector would not prevent the car from starting. Is this correct? Doesn't make sense to me that it wouldn't:: if there is no fuel being injected into the compression chamber, how would one have ignition? As well, there appears to be fuel at the base of two of the injectors. Would this mean I've got some bad seals there that need replacing, or (hope this next question doesn't sound ludicrous), or would the fuel "back up", as it were, if the injector were clogged and disallowing the fuel from being forwarded? Then, there's the injector pump, but I pulled the line & am getting fuel out of there. Then, we've got the glow plug system. This car's got some strange history, which may help us to know. The car was given to me about eight months ago - my landlord's father had died five years ago - the father had owned the car. The Mercedes sat at the house for five years without being started. The landlord tells me, "I guess I'll have to have it hauled off - a car won't start after sitting that long." I suggested that perhaps he should try to start it - he said, "I'll tell you what - if you can start the thing, you can have it."
I took a good battery up there, installed it, and that baby started right up on the first attempt! I mean, it didn't even hesitate!! So, I registered it and drove it every day for the next six months - it started every day, no problem; and it ran great! Then, when winter came, I chose to put a new battery in it 'cause the one I'd installed was old when it went in and was getting very tired. A friend R&R'd the battery (I bought a brand new DieHard Marine Heavy-Duty battery); and the car basically has not started since then! Straight away, it turned over very strongly, but just won't catch. And, on the first fire-off attempt after the installation of the new battery, I knew it wasn't going to start because it sounded a little differently. So, I followed the path required to R&R the battery, thinking that perhaps the guy knocked something loose, but to no avail - I found nothing. The thing is, the car ran great prior to changing the battery - what the heck??! I was not present when the guy did the R&R of the battery (regretably), so I asked him a few polite questions, like, "Could you have accidentally knocked something loose?" and, "Could you show me exactly what you did?" and, "Could you have inadvertently hooked it up backwards, and maybe some electrical thing got blown?" and, finally, "What the hell did you do to my car??!" Several days later, a mutual acquaintance told me that the guy asked him, "Hey, if I did hook the battery up wrong and tried to start it, could something have happened to it to make it not start?" Although the guy doesn't directly admit doing so, I'd say it is possible that it did occur. Considering this, would the different polarity hook-up be the causation for blowing out some sort of electrical part; relay; something of this nature; and what should I check first? Any suggestions would be greatly appreciated - thank you. Sincerely, Michaela