ZR-1 Net Registry Forums - View Single Post - 90 ZR-1 running bad.

zr1nsxgto · 07-10-2010

Hello folks. I have followed the ZR-1 Net for the last 16 years, but haven't contributed to much. I have a 90 ZR-1 with 7200 miles that is basically a brand new car. Over the last 18 months, I've only driven it 2 times and I have noticed a very bad miss/loss of power when you begin to aggresively open the throttle. It acts very similar to the air duct collapsing, but I put a insert in it immediately after acquiring it in 95. The #2 plug wire also has a split in it which has been there ever since I have had the car. I do have a new set of GM wires without the logos, but they have been in storage for 8 years. I also suspect there might be a plugged injector but am not certain as the problem is sporadic. When the engine is started cold, it runs great as it heats up. It continues to run very well after it gets fully warmed up until the engine is shut off. Then if you restart the engine hot, it stumbles and misses badly when you try to open the throttle. Shut if off, let it cool, and all is good again.

I do have good wrenching skills and am not afraid to work on the LT-5, but I'm no expert. I do work for Tony Stewart Racing and don't get too much free time to play with my cars. I have thought about maybe having Haibeck go through this car a "tune" it. I'm sure there are other issues that are age related. He probably has seen these symptoms a gazillion times and knows exactly where to start. I could well chase the problem for a while before correcting it. Any good suggestions would be appreciated.

07-10-2010	#1
zr1nsxgto Join Date: Apr 2007 Location: Greenwood Indiana Posts: 50	90 ZR-1 running bad. Hello folks. I have followed the ZR-1 Net for the last 16 years, but haven't contributed to much. I have a 90 ZR-1 with 7200 miles that is basically a brand new car. Over the last 18 months, I've only driven it 2 times and I have noticed a very bad miss/loss of power when you begin to aggresively open the throttle. It acts very similar to the air duct collapsing, but I put a insert in it immediately after acquiring it in 95. The #2 plug wire also has a split in it which has been there ever since I have had the car. I do have a new set of GM wires without the logos, but they have been in storage for 8 years. I also suspect there might be a plugged injector but am not certain as the problem is sporadic. When the engine is started cold, it runs great as it heats up. It continues to run very well after it gets fully warmed up until the engine is shut off. Then if you restart the engine hot, it stumbles and misses badly when you try to open the throttle. Shut if off, let it cool, and all is good again. I do have good wrenching skills and am not afraid to work on the LT-5, but I'm no expert. I do work for Tony Stewart Racing and don't get too much free time to play with my cars. I have thought about maybe having Haibeck go through this car a "tune" it. I'm sure there are other issues that are age related. He probably has seen these symptoms a gazillion times and knows exactly where to start. I could well chase the problem for a while before correcting it. Any good suggestions would be appreciated.