no suction!

[Joe]

My '65 Euro manual transmission model runs and idles well. However, when I removed the air filter from the injection pump, and started the car (cold), there was no suction at all at the hole where the air filter mounts.
Does this mean I need to get into adjusting the air screw and the various adjusting screws on the rear of the injection pump?
Thanks!
Joe

[hands_aus]

Hey Joe,
Sounds like your Inj Pump Thermostat may not be retracting. This would cause the air valve to  stay closed.
Maybe you need to test the Thermostat and also lubricate the air valve.
Be aware that getting the air valve and Thermostat to work properly can affect the running of the car both at idle and at driving speed.
Also it could affect the economy hence adjusting the air screw and the fuel screw on the inj pump.

Bob (Brisbane,Australia)
early 250 SL, RHD

[ja17]

Hello Joe,
The air valve in the warm up device is probably stuck. Take it off and apart and clean it. Your thermostat in this unit could also be defective as Bob has mentioned. Check the air slide valve first. I posted a reply  with pictures of the unit completely apart  a few weeks ago. Let me know if you cannot find it.


Joe Alexander
Blacklick, Ohio

[Joe]

Well, you're both right. I took the tower off and noticed that some of the gasket sealer I had put on the device to seal the tower had flowed down onto the valve, and had sealed it closed. I managed to take it apart and clean it up, and now it is smooth as silk.
What is the purpose of the 14mm nut on the side that holds the valve open or closed? I used it to hold the valve down when I assembled the tower so as to keep pressure off it.
More questions now:
1. I just cannot find a dip stick on the injector pump. I took of the side cover to clean out, and there was no oil there. I know about the hole in the top with the cannister filter on it, but don't know how to measure the amount of oil in the pump.
2. I disconnected the vacuum line to the distributor at the throttle body and connected a vacuum guage there. My intention was to adjust the mixture because the plugs are black. There is no vacuum showing on the guage until I rev the engine to about 2000 rpm, then it goes up to about 20. I held the rpms at this level, with the throttle linkage disconnected, by putting a screwdriver between the idle set screw son the throttle body and its stop. When I turned the idle air screw, it remained constant for several rotations and then fell off as the engine started to die. Without the screwdriver holding the throttle plate open, and the throttle linkage disconnected, I turned the idle air screw and could not get it show any vacuum.
3. I disconnected the throttle linkage from the injector pump and when I pressed down on the injector pump plate, the engine slowed down. This indicated a rich condition, which I already knew. Also, going back, when I was working in the throttle area, with the throttle linkage disconnected, I could get the engine to rev about 1000 rpm before it stumbled. This, too, indicates a rich condition.
Is my vacuum guage in need of replacement?
It sure is nice to be able to come in the house and do a search on this site for information while I am working on the car!
I'm pretty sure the various pieces of the throttle linkage are adjusted ok. I did this before starting on the idle air screw, etc.
Thanks for the help, guys.
Joe

[Joe]

Took the car out on Sunday for the first topless ride on a foliage tour. Felt real conspicuous, as did mia sposa. It ran very well until I got about 30 miles from home, and then the condenser blew. Then I felt even more conspicuous.
We hitched home and I bought a condenser at NAPA and returned to bring the car home.
I couldn't help noticing the gas guage went from full to half in the 30-mile trip. Gotta check out that csv.
In my fooling around on the engine, I connected the vacuum guage to the small hole on the throttle chamber where the butterfly valve is, and got no vacuum reading until I revved the engine to about 2000 rpm. Then it went to about 20. When I connect the guage on the larger hose that goes to the brake booster, I get 22 inches at idle. Any explanation for why the guage shows zero on the other connection?
Joe

[ja17]

Hello Joe,
Refresh my memory, what distributor number? Also check the injection pump "R" number, maybe someone has installed a later injection pump without a dip stick. Are you checking the vacuum where the line going to the distributor is connected? Make sure your condenser, coil, and ballast resistor are all compatable.

Joe Alexander
Blacklick, Ohio

[Joe]

Joe, the distributor is ok, I think. Believe it is an 046, and is cast iron. I found the dipstick, under the solenoid. I suctioned the old oil from the pump and it was very black. When I refilled the pump, I put in 260 ml, and it is far above the mark on the dipstick, with the dipstick screwed in. In fact, it is above the mark with the dipstick just resting on the hole. Which is correct, the 260 ml or to have the oil level on the mark with the dipstick screwed in?
I am running the 26kv coil with proper ballast resistor (from Dr. Benz) and points/condenser. Haven't checked the number on the pump.
Yes, the vacuum point at which I checked was the small port on the throttle body. Just pulled off the hose that goes to the distributor and connected the vacuum guage there. No vacuum until revs hit about 2000.
When I tried to adjust the idle mixture, I ended up screwing the idle speed screw on the pump all the way to the left, and the mixture is still too rich. I really suspect the csv.
Any advice is appreciated.
Joe

[Albert-230SL]

quote:Originally posted by Joe

 Which is correct, the 260 ml or to have the oil level on the mark with the dipstick screwed in?
Joe

Hi Joe,

It should have the oil level on the mark with the dipstick fully screwed in. If it's over the mark, it could affect the injection pump work.

When I had mine over the mark, adjusting CO and other gas readings was very difficult until we found the excess of oil.

Regards,



Albert de la Torre Chavalera
Barcelona (Catalunya/Spain)
Feb.'64 230 SL Euro 113042-10-002432