my 1985 240 DL won't run. It will idle pretty well (with a rythmic variation in RPM) and it will rev fine as long as the throttle is increased slowly, and it is out of gear. As soon as you put it into gear and let off the clutch, it stalls, even if you let off the clutch at 3k RPM, or if you hit the gas too quickly.

I just checked the o2 sensor (by unplugging it) and I didn't get the normal increase, and then decrease in RPM as I have when testing this in my other cars. There is no difference between when it is plugged in, or not. is this my problem? I tried to buy one at schucks today but they quoted me $184.00 for a new sensor!

I bought a new fuel filter to put in, but I can't get the car in a good place to jack it up until I can get it moved, and I've been thinking that since I can get it up to 6k RPM easy that the problem probably isn't the filter ( I could be wrong- I don't know that much about the fuel system). I checked the Ignition Control Module vacuum hose for blockage, but it seemed to be alright- at least I could feel a slight vaccum through it. I'd check the Fuel Pressure Regulator but I don't know where to find it on a non-turbo

Here's a couple other things I've noticed- tell me if they might be causing this:

* the fuel pump relay buzzes sometimes, I took it out and re-soldered the elbows but this sound still happens sometimes

*there's something wrong with the alternator/charging system. I've put 2 new batteries in the car, and they always end up drained the next day. and today, I coupldn't get the car to run unless the jumper cable were constantly hooked up to my other running car. alternator rebuild?

*there's a connector, that plugs into what sort of looks like a spark plug, or o2 sensor, right above my alternator that runs into the engine block. I'm not sure what it is, but the connecting wire is almost completely ripped off.

*my AMM was replaced and I'm not sure if it is OEM- how do I tell?, the car hasn't run right since then (but it didn't run right before either)

thanks

My 744 behaved similiar to this with bad AMM. If you unplug it do things change?
ALso when checking for charging voltage, check at the battery. should be 14+ volts.
It's hard to diagnose AMM's, I only found my problem with one after changing it to another car. Ie. if you know some one with a smooth running 85 240, put your AMM on their car.
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744 & 745 16v 4+OD, 245 SE auto, 242Ti 4+OD, 245DL auto parts car

Your O2 sensor will not keep the car from running, just running rich. And because of that, clean your spark plugs.

the fuel pump relay buzzes sometimes -- get a new one if the solder didn't work.

something wrong with the alternator -- That WILL keep your car from running and is probably your biggest problem. Check the voltage and change the brushes and then check the voltage again. After you get 14V from the altenator, then check the voltage regulator to make sure it is constant.

there's a connector, that plugs into what sort of looks like a spark plug, or o2 sensor, right above my alternator that runs into the engine block -- Sounds like your temp sensor. Make sure the wires are not broken and tape them up securely. Also will cause minor drivability problems.

There may be a short in your wiring harness, draining your battery. Check the voltage drop as you pull fuses, one by one, with the key out. Don't forget the fuel pump fuse.

Klaus
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98 V70Rawd(108Kmi), 95 854T(88K mi), 75 164E(173K mi)