Bringing the Champ back to fighting condition - ZR-1 Net Registry Forums

bmarcum · 3 Days Ago

Ok. I have been driving my 90 Z VIN1965 and it has not been a driven car for 24 years. Not sure the history and why it wasn't driven but for all signs (oil tags, and condition) it not been a sports car for 24 years.

I have a miss that is weird. It only misses when the secondary are on. It seems to only miss when warm. Still trying to confirm warm only miss.

Thoughts on what I am chasing. I don't have a scope for LT5 waste space, so I can't tell if it is a cylinder or a bank that is missing. I have not pulled the plugs yet. But it is very intriguing that it does not miss with secondary off. Thoughts? I am a big one for diagnosing then fixing vs just changing plugs and wires especially pulling the intake. Thanks to all my LT5 friends!

Starman · 2 Days Ago

You probably have one or more bad secondary injectors. There is a way detailed in this forum to check them at the ECM harness. If bad, replace them all. The original injectors are not ethanol resistant and short out. About 93 on did not have this problem.

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Starman · 2 Days Ago

As I recall you are looking for around 14 ohms resistance.

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Mystic ZR-1 · 6 Hours Ago

Replace the coils while you're in there....

3 Days Ago	#1
bmarcum Join Date: Oct 2018 Location: Indiana Posts: 56	Bringing the Champ back to fighting condition Ok. I have been driving my 90 Z VIN1965 and it has not been a driven car for 24 years. Not sure the history and why it wasn't driven but for all signs (oil tags, and condition) it not been a sports car for 24 years. I have a miss that is weird. It only misses when the secondary are on. It seems to only miss when warm. Still trying to confirm warm only miss. Thoughts on what I am chasing. I don't have a scope for LT5 waste space, so I can't tell if it is a cylinder or a bank that is missing. I have not pulled the plugs yet. But it is very intriguing that it does not miss with secondary off. Thoughts? I am a big one for diagnosing then fixing vs just changing plugs and wires especially pulling the intake. Thanks to all my LT5 friends!

2 Days Ago	#2
Starman Join Date: Sep 2008 Location: Speedway, IN Posts: 131	Re: Bringing the Champ back to fighting condition You probably have one or more bad secondary injectors. There is a way detailed in this forum to check them at the ECM harness. If bad, replace them all. The original injectors are not ethanol resistant and short out. About 93 on did not have this problem. Sent from my iPhone using ZR-1 Net Registry

2 Days Ago	#3
Starman Join Date: Sep 2008 Location: Speedway, IN Posts: 131	Re: Bringing the Champ back to fighting condition As I recall you are looking for around 14 ohms resistance. Sent from my iPhone using ZR-1 Net Registry

6 Hours Ago	#4
Mystic ZR-1 Join Date: Jan 2010 Location: Mystic CT Posts: 2,625	Re: Bringing the Champ back to fighting condition Replace the coils while you're in there....