3B MAF problem (or not)?

[shone190]

I have Audi 200 20V 3b and strange MAF problem, or something that that look like that. When MAF is attached engine works very bad, black rich smoke on exhaust, it also looks like all cylinders don't work until 3-4000rpm. Idle is very bad, about 600rpm and usually engine dies and it is hard to start it again. If I try to move the car it dies almost immediately.

In case i unplug MAF, the car starts great, run and rev great but check engine and MAF error code is presented, so the car is in LIMP mode and run very poor off course.

I tried four different MAFs that I know they are good (one brand new) and it is always same and bad as I mentioned with MAF connected.

Does anybody have any idea or suggest what can I try and what might be a problem?

Thanks a lot.

[Monkeymagic]

Have you cleaned the connections? Have you run a fault code check?

[shone190]

I checked everyhing from this link in section "Testing the MAF – Part 1, External Checks", another checks are for the MAF itself and I have four functional MAFs tried on another engine and works perfect (one brand new).

http://www.s2central.com/ds_G70.html

As I mentioned above, there are no fault codes when MAF is connected.

[simons2]

Sounds like it could be a leak on the inlet side, ie , boost leak

[shone190]

I will check that too, thanks.

[dr.strangelove]

X2 on the boost leak theory. One of my couplers blew off the intercooler and the car would not run. If you can pressurize the intake, istarting from where the maf hooks up, t's pretty easy to listen for a leak. Good luck.

[shone190]

X2 on the boost leak theory. One of my couplers blew off the intercooler and the car would not run. If you can pressurize the intake, istarting from where the maf hooks up, t's pretty easy to listen for a leak. Good luck.

I don't understand if there is so big boost leak that car with MAF connected at least can run and can't move the car, how is possible that without MAF the car works great, idle, rev, eveything is perfect, just the car is in SAFE mode so boost is limited and car goes as it has 100hp instead of 220hp.