S4 n/a With Fuel Lean Issue
 

Alright I am still trying to figure out what is going on with my car and
why I get a lean spike as well as a lean cruise. Sometimes with lite
throttle I can get 16 a/f. I have no air pump tired into my exhaust.
I just replaced the fuel filter, fuel pump, and fpr. I have a spare ecu, afm,
and boost sensor. I found a post that said to test secondary injectors
you can swap the wiring with the primaries at the ecu so that the car
runs on secondaries. I just did that and it idles fine. When I apply a little
throttle not going to 3800rpms or anything the car can stall. I am wondering if
that is sign of the injectors being bad. I know HAILERS is the one who posted
about switching and didn't know if that was normal. I really need help on this one
so I can get it back on the road.

Check your 02 sensor

I don't have an O2 sensor because I use an Safc to tune with. I have never had this problem before last August. I would run rich throughout the band with no O2. Any other thoughts? HAILERS any idea on the secondaries running like primaries?

Anyone have any ideas? I can run it on secondaries but if I rev it it stalls with the secondaries. Does that mean maybe my injectors are going bad?

How can you tell if your injector drivers are toast? If I use a dmm to check the voltage drop I don't see one and was wondering if that is because it can't pick it up or what?

If you're checking for a voltage drop related to the secondary injectors then the car has to be under load and above a certain rpm threshold for the secondary injectors to fire.

Ya I have done that. This is sort of picking up from last thread and this time i hope I can get this solved with the help of the forum. I have unplugged the boost sensor vacuum hose and tps to simulate load. I get a big lean spike right at 3800rpms. I have regrounded the ecu at least 3-4 times. Even with sensors unplugged I still get the lean spike.

Here is the link to the previous thread
https://www.rx7club.com/showthread.p...t=Blackfc3srx7

Any body have an advice I need help bad!