I got a new project that is my daily driver
First for me with the the K-Jet system and manual trans 4 speed "no od"!!!!!

Cost: $800 dollars
Drove home in it...60 miles
Owner had it parked for a few years...years of dog hair inside!!!!!!!! black widows too.
No major rust, two small spots only.

REPAIRS DONE:
Motor mount & tranny mount ( purrs nice and steady )
O2 sensor, plugs & wires, (made a big difference )
Oil, filter change with lucas oil stabilizer
Fuel filter, in-tank fuel pump, added Marvel Mystery Oil 4oz
Fuel relay
Battery, used alternator and belt
Antifreeze change
resistor change
differential fluid top off with gear oil mixed with oil stabilizer
manual trans fluid change(Type F trans fluid)
exhaust gasket

REPAIRS NEDED:
Cat Converter
main fuel pump
tie rod ends both sides; bushing kit
two front rotors and brake pads....
timing belt (will do tomorrow)
engine degrease and detail
smog it....and other cosmetics and nurturing.

 

I had a 79 wagon with the four speed and it was not so bad. Screamed a little over 70 but ran strong at 85mph from D.C. to Warwick, RI. K-Jet is stupid easy to work on as long as you get the Bentley Manuel and familiarize yourself with its operation. If I was close and you weren't going to buy it I would.

 

Thats a pretty nice looking car.

 

I bought it and I will buy the Bentley Manual...I take it in this manual you get more details and pictures? I bought the car two weeks ago and wanted to post some pics. I hope more members with similar k-Jet system experience post their trouble shooting methods.

A wagon would have been super nice...! DAMN THE M45 IS LOUD....! I don't go over 65 as I feel it will blow up and a gear will end up my wazoo! I added oil stabilizer and TYPE F fluid (per Haynes manual) and took care of 40% of the noise.

 

you can run a redblock at the redline all day long, as long as you have decent oil in it.


there's a pretty good site for older 240's with k-jet engines, called K-Jet.org | Mechanical Fuel Injection Power!

 

That's right I had forgotten about k-jet.org...THANKS...

I use (depending on my wallet thickness) high mileage oil 10/30 from Valvoline to Castrol but what is a good oil? I heard of purple something and synthetics a long with oil stabilizers like Lucas and other.

If I really can't afford a name brand I use walmart stuff...I rather do the oil change frequently with a lesser quality? oil than no oil change at all than wait till my wallet fattens up again...

 

I generally use 10W30 Mobil 1, bought when its on sale at Costco by the 6-pack.

any major brand oil is fine in an NA car as long as you change it every 5000 miles or so, along with the filter (I use Mann or Volvo branded filters exclusively). I like to use synth in a turbo because they get really hot and beat up the oil.

 

Yes, I would use Mann exclusively also. Thanks again

 

As far as the K-Jet goes all you have to worry about is vacum leaks, the pump making enough fuel pressure and being sure not to let any contaminates get into the fuel system if you have to open it up to work on it, i.e. fuel filter. It is the simplest fuel system of all as far as I am concerned. I have had one Volvo and four A1 VW with it and it has never left me stranded short of a pump going out. On the VWs the windshields leak and ruin the relays but you can very easily jump the relay with a wire to get back on the road. Oh yeah, all the VWs were a minimum of 18 years old and the one I have now is 31 years and still running strong. If you have any problems with it post on here and I can probably help.

 

if a kjet system does go bad, it can be really hard to fix. I have a k-jet mercedes benz 300E thats driving me nuts with crummy running, bad idle and stumbling off idle, and I'm almost sure its in the injection somewhere, either the fuel distributor assembly or the injectors themselves ... I've already cleaned the throttle body, and the air flow plate, and replaced the hydro-whazza actuator and the airflow plate position potentiometer, as both these were bad.

 

Thanks for the input, and have checked K-Jet.org (Very useful) On my particular 79 242, it is simple now that I got some replies and website digging....not much to it, and it does have a bit of hoses everywhere.

Today at the local yard I came across some MB and BMW'S with k-jet systems...the smaller 3 series on the BMWs has similar air flow plates, hose size, cold injection, stuff like that with minor differences...when I came across some MB's the system looks way more ****. Obiously 6 cyl or 8 cyl will add to the hose/tube count making it look like an oil refinery.

 

Pierce is correct. If K-Jet is disturbed it can be a headache to get it tuned back correctly but it will almost always keep the car running just not perfect. Though your problem may be the fact that you are working on a MB. Yes they were the first and at one time the best but much like the big three they have been basking in the glory of their own presence to long. Pierce, have you checked your cold fuel pressure and warm fuel pressure? Being as the injectors open at certain pressures these are very important. Has your system been opened up, contaminates really mess with the little passages in the distributor. Tried unplugging you O2 sensor to make sure it is not causing a lean condition? The seal around the idle adjust screw gets hard and will make them idle poorly and is often overlooked. Good luck with it.

 

the O2 sensor on that MB is new, that helped it, a little. the car mostly is in perfect blaance per the lamda duty cycle, that adjustment helped, a little. I've done 50 things to the car, each helps, or even seems to fix the problem, then a week later its back to funky. I'm about to push this low mileage 1991 300E into the maul of California's junker program ($1000 buy-back for old cars if they roll in on their own power). the outside of this car looks like crap, but the interior is like new, it only has 56000 miles on it, was a old ladies car who banged into too much stuff and lost her license, then it sat under pine needles for 15 years. once its running at speed, the power and everything runs fine, it only has problems coming off idle.

 

my 242 runs idles fine when I pour 4oz of marble mystery oil to a full tank.....if I fill the tank with gas and don't add the mystery oil, it will run in limp mode...jerking and....cutting off bad. my outside pump will need to be replaced...AND THE DREADED REGULATOR THAT COSTS 200 PLUS DOLLARS with core in hand at the counter.

 

you mean the fuel distributor ? or the fuel pressure regulator?

 

fuel pressure regulator...smaller by itself next to the distributor...I've read you can rebuild it but will try to swap it out for a Saab one I saw at the yard...same thing all connections and such.

 

this saab is k-jet, too? i believe the volvo k-jet wants 65psi fuel pressure (later LH cars are 42-44 psi)

 

yes, the particular Saab I saw....it is an 83 or later model....they shared the cold start injection, Bosch fuel distributor, and regulator. The regulator was the same...now the internal parts might regulate differently, yes I feel you on that one...but worth the try on my bucket of pennies budget....I am even trying the clear nylon fuel injector hoses it came with...I know I can use certain VW's fuel lines to injectors...keep posted.