Test injector pulse - ZR-1 Net Registry Forums

mmkkpro · 07-04-2020

Good morning guys, I bought a set of noid lights to test injector pulse at the injector connector. Do any of you guys know if I will get a pulse with the plenum removed. I have all the electrical connector under plenum disconnected and plenum is sitting on driver front tire. Thanks.

Macroblock · 07-06-2020

It is possible to test your ECM's ability to activate the injectors with the plenum removed but if the Ignition Module is removed you will not get any injection pulses while cranking the engine over.

Using a noid light allows you to test without actually injecting fuel into the intake port, but unless you have 8 noid lights, you will need to disconnect all the primary injectors and test one feed line with a noid light 1 at a time.

Here's how to simulate the ignition module and fool the ECM so that it sends its (-) signal to the injectors:

Locate your Crankcase Reference High circuit at position "A" on your Ignition Diagnostic Connector. Connect the clip side of a 12v test light to the positive terminal of the battery.

With the key turned to ON, quickly apply and remove the test light probe side to position "A" of the Diagnostic Connector to simulate an on and off input signal. The ECM will respond by activating the fuel pumps and the injectors.

For more info, refer to the Factory Service Manual under Direct Ignition System.

mmkkpro · 07-06-2020

Nice, thank you, so what I ended up doing was removing the ignition module from plenum, folding a shop rag and laying it on top of the coils. Connected the crank sensor and ignition connector to IM, leaving coil connection disconnected. I was able to let the IM lay where it lives on the engine. I then disconnected all primary injectors, testing each one with noid light one at a time, all worked except #6.
I then did the connector A test grounding pin 8 and #6 worked fine.
My conclusion is a bad injector driver for #6. Sending my ECM to MH this morning for him to test and fix if needed, also buying a memcal, maybe secondary delete, not sure my secondaries seem fine.
Thank you for taking the time to explain that procedure to me, I greatly appreciate it.

07-04-2020	#1
mmkkpro Join Date: Apr 2019 Location: Supply NC Posts: 124	Test injector pulse Good morning guys, I bought a set of noid lights to test injector pulse at the injector connector. Do any of you guys know if I will get a pulse with the plenum removed. I have all the electrical connector under plenum disconnected and plenum is sitting on driver front tire. Thanks.

07-06-2020	#2
Macroblock Join Date: May 2020 Location: Windsor Posts: 39	Re: Test injector pulse It is possible to test your ECM's ability to activate the injectors with the plenum removed but if the Ignition Module is removed you will not get any injection pulses while cranking the engine over. Using a noid light allows you to test without actually injecting fuel into the intake port, but unless you have 8 noid lights, you will need to disconnect all the primary injectors and test one feed line with a noid light 1 at a time. Here's how to simulate the ignition module and fool the ECM so that it sends its (-) signal to the injectors: Locate your Crankcase Reference High circuit at position "A" on your Ignition Diagnostic Connector. Connect the clip side of a 12v test light to the positive terminal of the battery. With the key turned to ON, quickly apply and remove the test light probe side to position "A" of the Diagnostic Connector to simulate an on and off input signal. The ECM will respond by activating the fuel pumps and the injectors. For more info, refer to the Factory Service Manual under Direct Ignition System.

07-06-2020	#3
mmkkpro Join Date: Apr 2019 Location: Supply NC Posts: 124	Re: Test injector pulse Nice, thank you, so what I ended up doing was removing the ignition module from plenum, folding a shop rag and laying it on top of the coils. Connected the crank sensor and ignition connector to IM, leaving coil connection disconnected. I was able to let the IM lay where it lives on the engine. I then disconnected all primary injectors, testing each one with noid light one at a time, all worked except #6. I then did the connector A test grounding pin 8 and #6 worked fine. My conclusion is a bad injector driver for #6. Sending my ECM to MH this morning for him to test and fix if needed, also buying a memcal, maybe secondary delete, not sure my secondaries seem fine. Thank you for taking the time to explain that procedure to me, I greatly appreciate it.