72 Mercedes Benz 280CE

[alabbasi]

Originally Posted by Mike D

Al, is it possible the battery is simply connected backwards? What does/doesn't work? I have never and I mean never, seen a "positive" earth vehicle from the '70's.

Mike, I don't think so because many other parts work but I need to double check. I sincerely hope now because I would probably have fried a bunch of the electrical components.

[Mike D]

If you do have the "negative" cable connected to "earth" (dang you British guys for using an obtuse term like "earth" for a vehicle insulated from the Earth by rubber tyres ) and the pump is original then I'm with Chuck on this one. It HAS to be the relay creating the reversed polarity on the pump. Depending on the wiring for the ECU then it can also cause a problem because what the ECU is seeing as "ground" is not "ground" but simply backfeeding through the pump. Clear as mud?

I know it's no help but the reversed wiring on the pump might be the key problem.

[alabbasi]

Originally Posted by mike d

(dang you british guys for using an obtuse term like "earth" for a vehicle insulated from the earth by rubber tyres :d)

watch it mate!

[Mike D]

What? I get no points for "tyres"?

[alabbasi]

Talking about tyres, I just scored a set of goodyear ultra ls touring in from NTB for $57 + tax. The regular price is $81 but after some fast talking about discount tires offering khumo's for $57, the agreed to match the price.

These are for the 450SLC but at that price, many of my cars will be getting new tires (tyres).

[tonkovich]

al: are you a...limey?

seriously, tho, what do u think of that 350se for sale? is that a good v-8? seems like it would be a euro/grey market deal? not worth the drive from texas? (hey i've never been there)

[alabbasi]

I have a euro 350SE but I have yet to drive it. It's a 73 with a 4 speed manual and no seat belts from the factory. I bought it on ebay from a guy in PA. One of the forum members was kind enough to store it and now it's in WV getting mechanically worked.

I have heard that the 350 is a much better engine then the 450. This would make sense as the 450 was a lower compression, longer stroke engine that produced the same power.

Everyone that i have spoken to says that the M116 3.5 is a sweet engine.

Yes, I am a Brit and I like many things that are British like tea over coffee and butter on my sandwiches.

[tonkovich]

hey al:
thanks for the info on the 350. i would assume the one in tx is euro, and not adjusted for u.s. smog /e.p.a. and specs (per wikipedia, go figure) are roughly 205hp and 280 torque; as good as 450 with less weight/slightly (?) better fuel economy and more power. the one in texas is an auto tho, a 4 speed would be a dream.

oh, my lady is a brit, from bournemouth. we have tea nightly. (no milk, thank you) and she has prepared a ploughman's lunch for me. (but no pasties, thank you.)

[cth350]

First, any 350 with an MPH speedo had it replaced on import.
Second, Al, I just took apart a 6.9 this afternoon and have a set of rear belts for you. Mounting the shoulder harnesses in the rear will require plastic parts that have the opening for them. I've got them in green. You don't want those.

So I take it you don't want to borrow my spare 280SE M110E D-jet parts or the manual as you never did send me your address to mail them.

-CTH

[alabbasi]

Charlie

Did you part out a 6.9? If so, I may know someone who needs a couple of self leveling valves. On the 350SE, from what Greg tells me, there are no belts at all on this car!! this seems to be factory as there are the appropriate blanking plates where the belts are supposed to mount.

I have the factory manuals and the d-jet manuals (the red ones) which cover the 280ce and the 280e. I havent requested the parts from you let because I don't think im there yet. I had power to the computer and to the trigger points a couple of weeks ago but no power to the fuel pump. Now I have a working fuel pump, the computer is not getting power!

If I can get to the point where everything is getting power but cannot get the car running or have it running poorly, then I'll be calling you for the parts. r

Of course, having four projects at one time (GMC pickup, SLC 5.0, 6.3 and 280CE) doesn't help.

[alabbasi]

OK more tinkering today, but gotten nowhere fast. I am getting voltage to the fuel computer and I am getting voltage to the trigger points.

The trigger point has 3 connector (imagine 1-2-3 pins on the trigger point). I get voltage on either 1 or 3 but no voltage back on 2 which I assume is common. When I test resistance, I do get continuity (between 1 and 2 and 2 and 3 as the distributor turns).

On powering the engine up, the fuel pump does engage and turn as the engine is running and I am getting power to the fuel injectors.

The fuel injectors have a two pin connector. When testing voltage on pin 1, I get 12.5 volts. When testing voltage on pin 2, I also get 12.5 volts. I tested this on injector 1, 2 and 6.

I'm assuming the problem that the injectors not pulsing and hence no fuel is getting into the combustion chamber.

With voltage going to both the injector pins, I'm assuming that the computer grounds one of the pins and causing the injector to pulse (does this sound right?).

I don't think that the problems are with the injectors themselves (at least one has to work right). So it takes me back to the computer.

This is a very very frustrating day. I can't believe that I have spent 3 weekends working on this car and i'm still no closer to getting it running.

[mercmad6.3]

Al,a simple quick test. Turn on the key, grab the throttle and turn it slowly towards full from idle. It MUST click 20 times evenly. No clicks,the throttle switch is dead or not receiving power.
If it clicks ,even only a few times,your ECU is OK,and the injectors are OK.
You haven't mentioned cleaning earth contacts .
It's always the first place to start. Do it in order, starting from the battery. Then the bell housing to chassis lead. then the bunches of brown cables screwed to the body in at least two places.
An ECU fualt is very rare on those because of it's location.

[Tomguy]

Al, on the 4.5, 1 pin is always ground. Hence the big block of wires for grounding on the intake manifold of 116 4.5's and the bundle behind the battery on 108/109 4.5's. Check your wiring harness' ground point.