Placebo effect -- or not?

[J. Huber]

So, I was looking for things to do and decided to change the air filter on the injection pump. Never had in 25 years... Although car has been very happy lately -- I think the change improved things even more. Or is it just my imagination? Like the K&N up front its hard to quantify. Would that filter play any substantial role in the IP performance?

James
63 230SL

[Naj ✝︎]

Hi, James,

quote:Would that filter play any substantial role in the IP performance?

Yes, on start/warm-up + depends on how much weight the car lost with that choked up filter  

naj

68 280SL

[TheEngineer]

I found the filter element paper shredded. It's hard to inspect

[Shvegel]

On warmup it can have a huge difference. Someone actually replated my filter during a rebuild of the pump. Needless to say the paper was gone. The metal disc from the top of the paper element used to flop around and occasionally block the additional air that the engine requires during warm up. It was a tough one to find.  

 I always recommend changing the filter before doing any warmup adjustments.

[J. Huber]

Shazaaam! During warm-up is where I seemed to notice a slight improvement...Thanks.

James
63 230SL

[waqas]

I tried removing my air filter, but it ran into the nearby coolant hose (going from the side of the head to the heater core inlet). Is this normal? Does one have to remove this hose in order to remove the IP air filter? (or is my coolant hose abnormally in the way).

Waqas ('Wa-kaas') in Austin, Texas

[91lux]

Hi
On my 230sl the previous owner or garage had interchanged the location of the filter and the airhose.Same treads.At first look differcult to find.Made idle speed impossible to adjust properly for couple year( adjusted by the airflap). When the thermostat closed it shutted of the air supply totally.Finally when it sorted out and the hose and filter were in correct location, it became perfect.I think a clogged filter will work the same way and make warm idle differcult

regards 91lux,Norway, 64 230 sl ,manual

[Vince Canepa]

Wagas - Some of the air filters have a stepped outer diameter that allows the filter to clear the coolant hose.  The aft end is smaller in diameter than the rest of the housing.  I always used those - I think I had to get them from the dealer as other sources had the uniform diameter version that would not clear the hose.

Vince Canepa

[J. Huber]

Hey Waqas. My filter came off very easily. The hose is near it but not in the way. Someone here mentioned I'd need a thin profile wrench -- but this is because area between the cannister to the pump housing is fairly narrow (where the nut is). I think it takes a 19mm. I had a 3/4 that fit. It came right off.

James
63 230SL

[TheEngineer]

Made a filter because my local friendly MB dealer took so long to get the replacement filter. Used the plate with the treaded boss and a paper element from a Fram fuel filter. Used epoxy to glue it all together. Works real well. Now I can inspect the filter visually for getting clogged.

[Shvegel]

Engineer,

The last time I bought one it was through thepartsbin.com Bosch part, same as MB.

[Shvegel]

Engineer,
They sell the Mann brand under "fuel injection pump"

Only $44 (I think I paid something like $10)

Don't splash through and puddles while you car is warming up until you get a new one.

"What happens when the unstoppable piston meets the uncompressible water?"

[Naj ✝︎]

quote:Originally posted by 91lux

Hi
Made idle speed impossible to adjust properly for couple year( adjusted by the airflap). When the thermostat closed it shutted of the air supply totally.Finally when it sorted out and the hose and filter were in correct location, it became perfect.regards 91lux,Norway, 64 230 sl ,manual

91lux,

The air from the little air filter should shut off completely.
If its letting some air thru when engine is warm, it is not right.
If you cannot adjust idle speed with the air screw near the main thermostat housing, your problems are elsewhere...

naj

68 280SL

[J. Huber]

Here is a picture of the new IP Filter (Bud's Benz: $38) and the original (inset). I believe the latter is the "stepped" variety that Vince spoke of. You can see that it wasn't obstructed by the coolant hose.



James
63 230SL