I have an S5 fc 90 na convertible. I thought that the ecu wasnīt sending signal to my sec. injectors. Thatīs because iīve checked at 3,800rpm ' 4000rpm the harness and have no signal at all, but when i rpm the engine up to 6,000rpm i got signal, both of them. Thatīs too many rpmīs. How can i solve that? I don't know what might be. Any ideas?

 

How did you Prove they don't come on til six grand?

Secondarys come on under LOAD and at least 3800 rpm.

An engine not under LOAD won't let the secondarys come online til there is a load over 3800rpm. Saying that you could be at 5 grand and the secondarys won't come on line unless there is a Load.

A load can be simulated in the driveway if the boost/pressure sensors vacuum line is removed and the vacuum line is plugged off. Then each time you rev to 3800 and above the secondays will come online.

 

^^^^Good God, you know your ****.

John ny

 

The early non turbo cars have a checkout of the secondary injectors and I attached it in a jpg.

I don't remember this being in the Turbo Fuel and Emissions section. But it works for turbos also. And frankly I don't remember having to remove the TPS connector, but then again, most of the time I had a digital meter backprobing one of the secondary injector wires at the ECU when doing this and also was probably driving the car when checking it out.

Also, if in the driveway with the vacuum line off the boost/pressure sensor, and reving the car in the driveway over 3800rpm, the sound of the engine gets crummy when you hit that 3800rpm speed, because the secondarys come online.

 

Yeah, gotta remove the TPS connector to do that or depin the TPS input wire at the ECU one.

 

Thanks Hailers for the info, i'll check it out.

 

Well, i drove the car 2 days ago below 3,800 rpm runs great. But when it gets above the 4,000 rpm or 50 mph the check engine light turns on and the car starts to fail, it doesn't want to accelerate more. i think it's cause the sec. injectors are not workin. I've checked the sec. inj. with an sthetoscope, vacuum line off the boost/pressure sensor, i've lift the back part of the car hehe, and have no positive results. i want to check continuity of the sec. injector harness but i haven't found the colors on the ecu. i don't know if the color changes or it goes first to another place.

 

Are you sure your not in LIMP mode? There's a code for a failing OMP on series five cars. Download the fault code and see what it is.


A long time ago, I used to just connect a digital meter to one of the secondary injector wires AT the ECU. The voltage will be the alternator output and will stay that way, until you hit 3800rpm under Load. Then the voltage will drop. Can't fail to notice it.

I never used a stethescope as shown in the FSM pages I attached. I always used a meter at the ECU secondary injector plug.

The secondary injector wires are shown in the S5 wiring diagrams and in the Fuel and Emissions section of the FSM.

http://www.rotorwiki.com/index.php/89-91_Error_Codes

 

Thanks for the info Hailers, i'll check this tomorrow.