dinkyredfc3s

Im having an issue figuring out if this car needed the resistors in-line for the injectors or if previous owner was overzealous....

The Rant:

It says it was assembled in 08/87 but behind the headlight on passengers side I have a aluminium box with a round white plug that has 6 wires going into it. the previous owner of the car wired up 4 resistors on the ecu side of the injector wires and its running 4 denso 720cc injectors (they give about 2.5-2.4ohms of resistance) i understand the whole pre june of 88 but im hearsay isnt enough to run the risk of burning something up....

The Facts:

My biggest issue is I just don't know WHERE to check to know for SURE if it needed those resistors or not and sadly it didnt have stock injectors installed OR i would have check the resistance of those and used that as my baseline.

Im running:

an 88 turbo 2 assembled 08/87
Rtek 2.1 (N332)
4 Denso 720cc with (2.4~2.6ohms of resistance)
Walbro fuel pump
A 6 wire electrical box, behind the headlight with a round plug

AND yes i have searched and came across info for people wanting to run Power FC's and talking about 1680cc injectors, also came across hailers posting some info that helped me out but still i want to actually be able to TEST something in the system that gives me data that points to the proper solution!

87 t-66

iTrader: (133)

the ecu wants to see high imp...so if you have low imp injectors, there should be resistors.

RotaryRocket88

iTrader: (7)

'87.5 and up cars had high impedance injectors stock, and would not have had a resistor pack connected to the harness. I'll bet the box you're looking at is the fuel pump resistor/relay, which is unrelated. All turbo S4s had them. An injector resistor pack has 5 wires and an oval yellowish plug.

From the sound of it, the previous owner did the right thing wiring resistors in at the ECU. The only other thing to consider is what the actual resistors are. Ideally, they should be 6 ohm, but up to 10 ohm will work.

dinkyredfc3s

great work! seems like this car IS in need of those resistors NOW its just a matter of figuring out why car leans out with 4 720cc injectors even @ 40% correction on 14psi or so.... AND the duty cycle reads 96% max at one point im still not too sure where so i gotta data log and see whats up


im guessing its the fuel pump not getting enough voltage because my alternator is a POS i think, and/or a conjuction of that and the fuelpump being a POS chinamen fake walbro it came with the car and it wouldnt surprise me...


thanks for all the help guys!

RotaryRocket88

iTrader: (7)

If you're concerned about fuel pump voltage, the typical thing to do is rewire it, so the resistor relay is removed. It switches voltage to 9V at idle and then back to 12V under load, but it can fail. Test the voltage at the fuel pump with a multimeter to figure it out.