Red Rocket

[Benz Dr.]

So the rocket continues to run well. Still have lots of things to fix but the mechanical part is getting better.

I've been watching my fuel mileage and it seems to be running around 1 liter per 10 km at 3,000 RPM road speed. This equates to about 29 miles per imperial gallon or 24 per US gallon. I did some testing with different octaine fuels and it seems to like 94 the best. It will run on regular but you have to go slowly with the car. It will still ping a little bit on 91  but 94 is only 1.1 cents a litre more than 92 octain ( about .90 per liter CDN for 94 ) so I figured why not. Coolant temps seem to be lower on the better fuel so I'll probably run it when I can. I figure I should be able to drive a minimum of 600 KM on a tank of fuel and could go 700 if I was driving slowly.



Daniel G Caron

[Cees Klumper]

That's very good mileage Dan. Most people I hear (and myself) are lucky to get 8 km to the liter. Some previous owner put in a small capacity fuel tank in my '69 280 SL and as a consequence I have to refuel every 400 or so km.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Benz Dr.]

Hi Cees,
I thought it was pretty good for a 2.5 liter engine from that time period. I put new fuel injectors in when I first rebuilt the engine and I'm sure they're good for 1 KM per liter increase. I can't run this engine any leaner but when I switch to synthetic oil I may break the 30 MPG barrier on a consistant basis.
It has a lot of power when I want it and feels nearly as fast as a 280SL. The five speed trans is nice but they won't shift as smoothly as a 4 speed. I don't push something that rare and difficult to repair. I think all the head work I did is the real key to the economy and performance. This was a lot of work but seems worth it now.
I still have to fix my cold start valve - the relay isn't working. Now that it's getting cooler it takes some spinning to get it to fire up. I'm sure it would fire instanly once I fix it. I may replace the fuel pump because it's so old. It still works but makes strange noises that could be telling me it's near the end of its life. Sometimes the engine will sputter a little bit just driving along which could be fluctuations in fuel pressure. Could also be stray voltage from ignition wires.
Once I get a straight rim to replace the one that's bent it will feel a lot more smooth on the road. Kind of vibrates at the speed I usually drive ( it just had to be that speed too ) but it's not too bad.
I think my clock quit working. It blows the fuse as soon as I try and replace it so it's a good guess. Aside from no interior light I can live with that until I redo the dash pieces. The interior is pretty ratty after sitting for so may years unused. The mechanicals are nice and shiny though...........

Daniel G Caron

[70chevelle]

Benz Dr. - Should these cars start as new fuel injection cars do, without using the gas pedal?  I have to give mine gas to get it started, but I know I have linkage issues and CSV issues.

70 Chevelle 13.7 @ 99.7
70 280 SL Silver/Black top
05 C230 Kompressor
03 Dodge Durango SLT

[Benz Dr.]

Mine isn't starting right eiter unless it's already warmed up. I know the relay isn't working and that's all I need.
I tried fixing it but I guess it's worn out. It's possible to remove the cover on the relay and close the contact points up a bit - they can't touch though or the CSV would be on all the time. If the magnet inside the relay is weak it won't pull the points closed and the CSV won't fuction.
If everything is working properly you should be able to start the car by simply turning the key without pressing the gas pedal. Engine should fire up any time you hit the ignition switch.

Daniel G Caron

[LFrank]

<<Engine should fire up any time you hit the ignition switch.>>
Thanks, Dan, for valuable self-diagnosis. (Mine sure doesn't!)


LFrank
Washington DC
65 230 sl - auto
DB334/Hellblau