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happy holidays to all. I have free time wanted to put this out there. Long story short car was sent home without a tune D/T a VVT issue. Idled and ran great, car is home now it's idling terrible. I have narrowed it down to injector 4 no seeing a good voltage. Running sequential, injector 3 is seeing 14v and 4 is not. Maybe the tuner hit a key on accident and shut off injector 4 I don't know much about MS. Here are some pictures. The meter is directly on the wire harness I am seeing the same numbers on the injectors. Injector 3 Injector 4
is it possible to do a test to see if MS3 is working right? Or turn injector 4 on or tweak it?
The 14v comes from the wiring harness/main relay. The MS only gives the ground signal. Can’t quite see what you’re testing with your DMM.
I was thinking it should be lower voltage also but in all transparency ECU is beyond my understanding. I wired injector 3 and 4 to the ECU, 1 and 2 are to the harness.
Engine was idling smoothly now it isn't. Maybe I wired the sequential wrong from the start. #3 injector is getting 14v for sure right off the plug where I tested, #4 is getting much less. I am testing at the arrows.
You have a short somewhere in your wiring if you have 14v at the injector output wiring. Strip any loom off and check all connections.
I don't have a short, from injector 3-4 direct wire to the MS3.
I checked all the injector resistance, they are all 14.6.
voltage at the pin connector on the ecu is 14v on injector 1 and 2 wires to the stocked pins. I was expecting 5V for signal.
voltage at the pin connector on the ECU is .50 on injectors 3-4 wires to 4Y and 4Z. I must have not been making contract on injector 3 pin and made contact with another pin the first time.
I double check continuity on my wires from 3-4 no issues.
Car is running on 2 cylinders 1 and 2. I can turn it over with injector 3-4 unplugged. Granted it's shaking.
I'm suspecting MS3 is the problem. If anyone has suggestion please share.
It was at the shop getting tuned the tuner denies ever altering programming.
Last resort is running batch and I prefer not to do that.
You're confusing an output for an input. Some sensors (inputs) use 5v. Injectors and coils are outputs. They have battery voltage (+12-14v) on one pin any time the key is on. The ECU pulses the ground signal. The injector is a solenoid, meaning it's a very tiny, very long piece of wire wrapped around a metal valve. Applying voltage to the two ends turns the coil into a magnet, pulls the valve open, and allows fuel into the combustion chamber.
There is a chance you're reading the 14v from the other pin through this tiny piece of wire. Unplug the injector and check again. If voltage is still at the injector output, you probably have a short. Unplug the ECU and check again. If there is still voltage, again, you have a short.
Injector outputs fire in order, A-H (or A-D for a 4 cylinder engine), so they must be wired in the correct mechanical firing order, which in the Miata's case is 1-3-4-2. You can check your firing order settings in Tunerstuidos, but it would be very weird to adjust this while tuning.
You're confusing an output for an input. Some sensors (inputs) use 5v. Injectors and coils are outputs. They have battery voltage (+12-14v) on one pin any time the key is on. The ECU pulses the ground signal. The injector is a solenoid, meaning it's a very tiny, very long piece of wire wrapped around a metal valve. Applying voltage to the two ends turns the coil into a magnet, pulls the valve open, and allows fuel into the combustion chamber.
There is a chance you're reading the 14v from the other pin through this tiny piece of wire. Unplug the injector and check again. If voltage is still at the injector output, you probably have a short. Unplug the ECU and check again. If there is still voltage, again, you have a short.
Injector outputs fire in order, A-H (or A-D for a 4 cylinder engine), so they must be wired in the correct mechanical firing order, which in the Miata's case is 1-3-4-2. You can check your firing order settings in Tunerstuidos, but it would be very weird to adjust this while tuning.
Definitely not reading other wires I stripped the wire back some today. I also wired the injectors to batch and switched the setting on TS and the problem was fixed but I want to use sequential. I checked continuity on what ever wire I could and nothing is leading me to believe wiring is the issue. I also did an injector test with the wiring and TS set to sequential I get a good pulses on my test light on injector 1 and 2 while 3 and 4 is not functioning.
The pin output on MS3 4Y and 4Z (90-93) are dead no output while 4U and 4V have an output of 14V for injector 1 and 2. MS has a short not the wiring to the injectors. Makes me wonder if other issues are there with the MS.
My setting are nearly same as the screen shot. with that said is there another option of controlling the injectors using MS options plug?
Injector help.
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