bond343

hello,

i'm in the process of trying to bring a 1987 audi quattro 4000 back to life. this is the 5 cylinder motor.

the thing i'm trying to understand is about the cis fuel injection.

the problem i'm having is that the car won't run unless i lift up on the airflow sensor plate manually. i have to hold it some pliers because once the car starts running the plate tries to pull back in. i have to use pliers because it pulls back in too forcefully to hold up by hand. when the car is not running the plate moves easily and doesn't suck back down like it does when running.

i read somewhere this is because the fuel pressure is too high, but i don't have enough understanding of how cis fuel injection to understand exactly what's going on here.

if the fuel pressure regulator was not drawing the proper vacuum from the airbox, is this a symptom that would occur?

i'm also looking for a new intake boot, but the only ones i can seem to find are for the 4 cyl models and don't have the same ports as my boot, anyone know where i can get a 5 cyl boot?

thanks for the help

joe

Blewtoon

Vacuum leaks are the most common problem with CIS. The vacuum needs to move that big disc to activate the fuel dist. If the boot or the hoses have even a minor leak it won't work properly.