docmirror

We are troubleshooting no injector pulse. The LH has been tested and swapped. The LH relay has been tested and swapped. we fire on carb cleaner, but have NO injector pulse. I suspect the alarm system is inhibiting the inj pulse. If you KNOW how to bypass it, please provide the process.

SeanR

Behind the glove box.

Bigfoot928

Is EZK getting power? Alarm stops power to ezk.

docmirror

Yeah, I don't have an alarm problem. Thx. The EZK is firing and I'm getting spark, so no alarm issue. Something from the EZK is not getting over to the LH to say 'pulse'. I'll check the wiring bundle later. Curry came over and we tested my LH in his car, and his LH in my car. No LH problem, just my car won't pulse. grrrrrrrr

Bigfoot928

IIRC the ezk generates the tach signal which also goes to the LH. Does the tach jump when you try to start?

docmirror

Yes. It fires on carb cleaner. Something between the EZK and the LH not communicating.

Bigfoot928

sounds like a harness issue. time to break out the meter.

soontobered84

That's kinda what we came up with as well.

Doc trailered it in to my house on a Saturday afternoon earlier in baseball season. We (the collective we)replaced the fuel pump and charged the battery and it started right up back then.

SeanR

docmirror

No, it has spark and starts on carb cleaner. From what I can see, that lets out the ign switch. Just no inj pulse. I have 12VDC on both inj pins, but no pulse, no click.

Bill Ball

If there is a short anywhere in the injector harness, most likely from frayed wires under one of the injector plug boots, none of the injectors will fire. My diagnostic skills in this area have faded since I ceased wrenching much over the last 5 years, but I can remember solving this by finding the short in a buddy's 928.

docmirror

That's the most likely thing, as I touched all of the harness when swapping the injectors. I have solid 12V on both pins. Now I need to pull all the leads off the inj, take the LH conn off and start metering them. It's starting to cool off here, and I can spend some time at that soon.

docmirror

With all inj connections on right side off and the inj LH harness disconnected I have 4.8 ohms on the two wires of the inj socket. So it's not a dead short. I'll take the driver side off later and see what I have.

Bigfoot928

unless you opened the short removing the injector connectors.