The Return of Tubby Z28

**Stormyweather** · 07-16-2017, 10:27 PM

Code 18 crank or trigger open?

At home on the sofa watching the game.

***SSlowBoat*** · 07-16-2017, 10:28 PM

Originally Posted by Stormyweather

Code 18 crank or trigger open?

At home on the sofa watching the game.

no, code 18 on a lt1 is injector circuit. something wrong with either an injector, the wiring, or ecm driver for injectors.

Sent from my SAMSUNG-SM-G935A using Tapatalk

**Stormyweather** · 07-16-2017, 10:32 PM

Crap might be your switch then.

At home on the sofa watching the game.

***SSlowBoat*** · 07-17-2017, 08:16 AM

well, just started working on it again. even though injector 8 ohm good, it seems to be dead. plugged a spare injector into #8 harness plug, cleared code, started car, no more code

Sent from my SAMSUNG-SM-G935A using Tapatalk

**Injuneer** · 07-17-2017, 10:54 AM

GM spec for minimum injector resistance is 11.6 ohms. Per the factory manual description for DTC 18.

Glad you found it. I was going to respond to your original question. I have seen people get incorrect results with attempts to improvise a 'noid light from an incandescent bulb. Also was going to ask if there was any possibility that you had a leaking coil with the new ignition setup. Could be interfering with the injector wiring, inducing enough current to provide a ground. But that's no longer an issue.

***SSlowBoat*** · 07-17-2017, 11:02 AM

Originally Posted by Injuneer

GM spec for minimum injector resistance is 11.6 ohms. Per the factory manual description for DTC 18.

Glad you found it. I was going to respond to your original question. I have seen people get incorrect results with attempts to improvise a 'noid light from an incandescent bulb. Also was going to ask if there was any possibility that you had a leaking coil with the new ignition setup. Could be interfering with the injector wiring, inducing enough current to provide a ground. But that's no longer an issue.

yeah the problem seems to have gone away at this time. that coil in the back will get swapped when my 4 replacement used ones arrive. I also spoke to BP automotive about a new engine harness, I think the age and brittleness of this 27 year old harness are starting to show.

it was whacky too, because I replaced injector, cleared code started car and code returned. I almost set the car on fire at that point. unplugged it and plugged it back in a few times and it went away for now.

Sent from my SAMSUNG-SM-G935A using Tapatalk

**Injuneer** · 07-17-2017, 12:35 PM

Running a solid roller lifter cam, I found it easier to keep the coils off the valve covers, out of sight. And no, no problems with them getting wet in this location.