'89 rough performance at steady throttle
Thread Starter
8th Gear
Joined: Jun 2007
Posts: 8
Likes: 0
'89 rough performance at steady throttle
Hello everyone.
I had a set of original Multec injectors go bad on me at about 60k. Prior to the pressure drop on 5 of 8 injectors, the car ran smooth. I replaced them with an aftermarket set from Accel that run .5lbs higher than the Multecs. After replacement I found the engine would 'bump' significantly at steady throttle on the highway. Within 5000 miles or so, one of the Accels came apart and dumped fuel into the cylinder causing the engine to lock. I had the local Corvette center replace the Accels with OEM Multecs.
Long story short, the problem is continuing. At steady throttle, the engine will bump erratically like it is missing. I have narrowed this down to both operating temperatures above 180 degrees and below 2800rpms. If I keep the car in a lower gear to keep the engine above 2800, it runs very well and has excellent responsiveness. If the engine is below 180 degrees, the problem seems non-existent or at most indistinguishable from road vibration.
Any insight into this would be extremely helpful.
Additional note: No check engine light. Checked wires and they are seated properly. Plugs are new.
Chris
I had a set of original Multec injectors go bad on me at about 60k. Prior to the pressure drop on 5 of 8 injectors, the car ran smooth. I replaced them with an aftermarket set from Accel that run .5lbs higher than the Multecs. After replacement I found the engine would 'bump' significantly at steady throttle on the highway. Within 5000 miles or so, one of the Accels came apart and dumped fuel into the cylinder causing the engine to lock. I had the local Corvette center replace the Accels with OEM Multecs.
Long story short, the problem is continuing. At steady throttle, the engine will bump erratically like it is missing. I have narrowed this down to both operating temperatures above 180 degrees and below 2800rpms. If I keep the car in a lower gear to keep the engine above 2800, it runs very well and has excellent responsiveness. If the engine is below 180 degrees, the problem seems non-existent or at most indistinguishable from road vibration.
Any insight into this would be extremely helpful.
Additional note: No check engine light. Checked wires and they are seated properly. Plugs are new.
Chris
Last edited by mig29man; Jun 22, 2013 at 10:33 AM.
Thread Starter
8th Gear
Joined: Jun 2007
Posts: 8
Likes: 0
I think I found the problem. Looks like a plug wire clip on the driver's side broke and one of the wires was resting against a rail there. We're going to try replacing the set and securing them to see if it is grounding out at lower rpms.
