Oz928BOY

Hi i just got my car('83 928S 5speed, euro) back from the mechanic 2days ago and i noticed a grinding/rattling sound round the left side of the engine bay.
It seemed to come and go...anyway the next day i was driving back to the mechanic and i smelt a rubber burn, but no effect to the driving of the car, seemed to actualy drive better! thinking that as we have had a few fires in the past few days (in my City) i figured it was that.
So i get to the mechanic and he lifts the hood no sound i was like what the , then he noticed that the fan belt was not moving...the air-pump had siezed up and the belt had melted!
Ive noticed that many 928 owners have removed the pump and cap the plumbing and also replace the cats with hi-flow metalic cats or no cats.
I was wondering if there is anything that needs to have attention like the air that the pump provides for the throttle/Fuel injection(K-Jet)! is it an issue?
Cheers

76FJ55

you can remove the pump without effecting the fuel metering. The pump does not pull from the metered air goin into the engine and it dumps the air into the exhaust just before the cat the intent is to ensure sufficent air in the system for the cats to work during the initial cold start. since all engines require cold start enrich ment the pump augments the oxygen in the exhaust to help cat performance. the pump only runs after cold start andfor a limited time. the majority of the time the pump has no function. You can either plug the line to the cats and run the original exhaust or do a cat delete or run high flow cats, your choice. the system will function fine with any of these configurations.

Oz928BOY

Thank you 76FJ55
I wauld realy love to get my hands on an X-pipe ...anyone selling 1 and can deliver to Australia?

GlenL

Oz928,

I don't believe you have catalytic converters on you engine. The K-jet has air injection through the heads simply to add fresh O2 to the exhaust. This causes some CO to burn and lowers tailpipe emissions. Used to be called "AIR" for Air Injection Reactor back in the 70's before cats were mandated in the US.

I don't know what type of inspection your car has, but you can safely remove the entire system from engine life and performance perspectives.

Searching will find the correct belt to connect the flywheel to the fan. Then you can remove the pump and all the plumbing. The plugs and seals on the back of the heads are still available. There is also an idler pulley that replaces the pump and you might find that at a breakers.

On my Euro K-jet car I gutted the pump so it's just being a tensioner and removed all the tube and valves. A much cleaner-looking engine is the only result.

More discussion and the plug P/Ns are here:
https://rennlist.com/forums/928-foru...-delete-s.html

LEADASS

I deleted the whole air pump system, converted to an electric fan, and put on an x-pipe. Wow what an improvement. The motor runs significantly stronger.

Oz928BOY

Hi thanks for the info guys i have removed the Air pump and installed a short belt(20inch) for the rad fan and it works great! I still need to remove all the plumbing but will do this when i get the exhaust done(cross flow) i noticed that the plumbing leads to a small cylinder type of gadjet that splits into 2 areas! 1 is the cold air intake tube and the other seems to be for the exhaust, what does this gadjet do what is its perpose do i need it, it has wiring so im guessing its mechanical...sorry for the numbnut discription but im new to the mech world of cars!!!

GlenL

That's some sort of pressure regulator or bypass. It goes. All the plumbing goes. Get the plugs for the heads and take the rest of the stuff off

SnakeFeeder

I did exactly the same thing recently when my air pump started making noises at around 2000rpm. I must have a different sized pully on the fan though...mine took a 19 inch belt.
I haven't bothered doing anything about the plumbing though...does this matter?

jpitman2

I removed my airpump some time ago. All I did with the other plumbing was to plug the hose on top of the cam case where the air used to go in - broom handle fits nicely.
jp 83 EURO S AT 52k, P110 Brian Long.

andywarhol

I wonder what is air pump for in my "86 4.7 european v, which has no cats (only factory mufflers)?
pump started to be a liitle bit noisy when cold so I wonder to throw it away.
what could cause deletion of the pump in this case?

ROG100

928sRus sells the X pipe and Y pipe and ships to Australia.