Alpine951

I am wondering if I may have some wiring problems with the fuel injector harness. I replaced the connectors already. Any specific walkthrough using a multimeter would be greatly appreciated.

Humboldtgrin

You use Noyd lights. Or a test light to see the pulse of the light. Or an oscilloscope if you have one.

Raceboy

Injectors are Motronic pins 16 and 17 (cylinders 1+2 and 3+4 are paired), just measure continuity against injector connector signal pins (where there is no 12v with ignition on).

Alpine951

not quite following what you mean. Do I turn ignition on and stick both probes from the multimeter into the 2 pins in one injector? If so what would the result be?

Tom M'Guinn

Simplest test is just to wiggle/shake the harness with the motor running and see if it changes the idle at all. You can ohm out the wires as raceboy suggested (just check with a multimeter to make sure there is no short of open circuit in the wires) but that's not a good way to find bad connectors that work 99% of the time, and drive you nuts the other 1% of the time.

It might be worth posting a thread explaining the problem you are having (again?) and what you've checked to fix it... I see you asking about a lot of tests, but I can't remember what your issues are....

Alpine951

wiggling doesn't do anything. replaced injector connectors 2 years ago. lets see. where do I start. I put in a new Vitesse Maf. car ran great although I never did a wide open throttle run until 2 months after installing it. One night I buried the gas pedal to the floor on the way home from work and ever since the next morning the car would idle bad, low idle speed, and afr at idle of 17+. sometimes stall. car would run great while cruising and on boost with good afr. most likely culprit would be a vacuum leak. smoke tested, pressure tested, sprayed starting fluid everywhere but didn't find any leaks. someone said maybe not a vacuum leak. try disconnecting each injector connector to see what happens to the idle, meaning the idle should change and if the idle doesn't change when disconnecting the injector clip then that injector or related wiring may be the culprit. idle changed when disconnecting each one. someone else said measuring temps of the header pipe might be a better test. so with my laser beam pyrometer I took temp measurements. #1 was 100 degrees cooler. swapped #1 and #2 injector, #1 flange was still cooler. same thing when I swapped spark plugs, and swapped plug wires . if I go to FQS #1 idle is perfect both in quality, speed and afr, but afr on boost is into low 10's.

Alpine951

so after searching here for a while and googling too I found that I should have 12v on each injector clip with the ignition on. checked my car and every pin is 12v.