7a low on power

[MISTER T 1997]

I wanted to know what you guys think about my 7a it feels low on power until you hit about 4000rpm and the power kicks back in it smells like it is too rich but I have tried adjusting the air fuel rate but it’s not done much I have replaced knock sensors and the lambda sensor both made a small difference I cannot see any air leaks but the previous owner has removed a few bits one of which is the pipe that goes from the air intake to the crack I believe it has been blocked off in the intake side but I don’t know if that’s the problem or not?

[blux]

still on the old hitachi injectors?
hey might be not sealing fully and dripping to much fuel into the engine. dripping injectors also give a shakking effect on idle because it will run to rich.
Had this in my old 7a, on changing the injectors to bosch units idle was better, more power in low range.

[Bowie69]

If you aren't used to the 7A, they pull OK until 4000rpm, when the real power kicks in, it is just a feature.

Other running issues can take a while to track down....

[steve briance]

Whatever you have done adjusting air fuel ratio won't make any difference to the mixture running as that is controlled by the lambda probe feeding back to the ecu, the map in the ecu controls mixture. Not adjustable other than at idle.

Do a Google search or search this forum to see how to check fault codes, your car may tell you what is up.

[MISTER T 1997]

I have a adjustable maf sensor but I don’t feel anything on idle that doesn’t seem normal I did know about the power kicking in at high rpm but I have only ever driven mine so I was un sure if it was right

[steve briance]

The MAF is adjustable but did you follow the procedure to put it into set up mode by placing a fuse in the top of the fuel pump relay? It will still only adjust Idle mixture up to around 1200rpm but it won't do anything without the fuse going in the relay!

[MISTER T 1997]

No it was on the car when I bought it but if you can give any information I can set it up

[steve briance]

Let's see a photo - it will help people to understand what is going on with your engine. You mention something being blocked off, that doesn't sound right.

[Bowie69]

Sounds like the crankcase breather has just been rerouted to not go into the engine.

If it has been blocked off, then this is no good, the engine needs a way to release crankcase pressure.

[MISTER T 1997]

Yes I believe it is a crank breather and it is venting to the air but where it should go in the rubber intake is blanked of and here is the maf sensor

[steve briance]

That MAF is original fit to all 7a cars, the process of adjusting them is found by typing 'Idle mixture adjustment audi 7a'. Checkout workshop manuals link.

[MISTER T 1997]

I just checked for any vacuum leaks and I found the pipe that goes from the throttle body to the carbon can solenoid is not holding vacuum is this right if not what can be done

[Greg_S]

Is it the short section of hose alone that is leaking?