Extreme rich condition

[XfireZ51]

When u turn ignition ON, do not start motor, does SES flash ONCE and then remain ON until motor is started? Or does it not FLASH and stay ON after motor start?

[A26B]

Do your ECM?s have a GM PN still?
Please post the numbers


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[Perry Mitchell]

Hey Jerry. Back from vacation? The original ECM from the wrecked ZR does not have any numbers or sticker. The re-man ECM has a 16163993 on the box along with a DELCO sticker but no info on the ECM itself. Since both ECM's had the same effect, I am going to re-install the original ECM that ran the motor prior to the car being wrecked. I have been asked if the injectors you sell are new or reconditioned. I believe they are new, correct?

[Perry Mitchell]

[QUOTE=XfireZ51;311129]When u turn ignition ON, do not start motor, does SES flash ONCE and then remain ON until motor is started? Or does it not FLASH and stay ON after motor start?[/QUOTE

When I turn the ignition on, the SES light flashes once and then stays on. Then when I start the motor, the light goes dim, barely visible. I hadn't noticed that before, interesting.

[A26B]

Originally Posted by Perry Mitchell

Hey Jerry. Back from vacation? The original ECM from the wrecked ZR does not have any numbers or sticker. The re-man ECM has a 16163993 on the box along with a DELCO sticker but no info on the ECM itself. Since both ECM's had the same effect, I am going to re-install the original ECM that ran the motor prior to the car being wrecked. I have been asked if the injectors you sell are new or reconditioned. I believe they are new, correct?

Yes, they are new, flow-matched.

[XfireZ51]

3993 is a ZR ECM. Same as my ECM in 92.

[Marc Haibeck]

Just to be sure, I made a copy of your calibration and installed it on a '91 ZR-1. The engine idled smoothly with the normal low level of fumes for a cold engine. After two minutes the system went into closed loop at 118 degrees F. The car has catalysts. After two minutes there were no fumes at all.

Does your wiring harness have the Secondary Relay modules? I'm wondering if the fuel injectors are wired together. If so, there would be twice the fuel delivery than the engine needs at idle. Both injectors are driven when the throttle is opened .5% or more. Does the rich condition go away when the engine is idled at 1000 rpm?

Is your SES lamp an LED? If so it is normal for it to glow dimly when it should be off. A resistor needs to be added in series to reduce the drive current when a LED is used.

[Perry Mitchell]

Marc, I wasn't concerned with the work you did on my prom but thank you for confirming that. I am not familiar with the secondary relay modules. Where would I begin looking for them? I have never let the car run for 2 minutes to get warmed up. I will back the car out of the shop so it can run without smoking me out. The car does not have cats. My SES light is an LED so good to know that the dim condition is not a concern.

[-=Jeff=-]

Do you know how the injectors are wired in the harness?

Module looks like this:

[Perry Mitchell]

I don't have anything that looks like that and the wire harness instructions doesn't make any mention of it. When I removed the harness from the wrecked ZR, I don't remember a sensor that looked like that. Where would it have been in a stock 91? What color would the wires/connector be? I still have the cut up original harness which I use for reference all the time. Each pair of wires for each injector were pre wired to the connectors. Each pair of wires were run to a panel that was supplied with the harness. The computer was prewired to this panel. The instructions told me which terminal on the panel to connect the injector wires to which indirectly connected them to the corresponding pin on the computer. Hope that makes sense.