Alright guys time to get serious with this problem ive been having...
I acquired the car roughly 3 years ago, a 1984 300zx Turbo AE. Three years ago the first thing i did was replace the timing belt and attempted to start the motor. The engine ran rough, but it ran. not only was the belt replaced but the tensioner as well. Now roughly a year ago i discovered the belt had been off by one tooth for roughly one season of auto crossing, causing me to not be able to properly set the timing with a timing light.
Once i had fixed the timing belt, the engine felt much stronger, but still had a miss to it. So i replaced the spark plug wires, spark plugs, rotor, and cap. The injector recall was also done when the engine first fired up leaving me with new injectors. The way the harness is still laid out though, i am led to believe that the dealership did not rewire the injectors to batch fire but left them as is.
Back in September of this year, driving down the highway, the engine began bogging down really badly, and running like complete ass at low RPM's and would not idle.
What had happened is the engine had run lean and caused a good portion of the edge of the piston to melt away, and leave 0 compression in that cylinder at lower RPM's and at idle.
I have now rebuilt the engine using an NA block i have, and have left everything stock on the engine.
While the injectors were out i eliminated them as a potential cause for the miss, and engine destruction by placing them on a pulse machine, on which i could set a certain injector pulse, and run a controlled amount of fuel through the injectors. Each injector delivered the identical amount of fuel with a perfect spray pattern.
This past weekend i just got the engine re-installed in the car, and fired up ( Great easter weekend for me ) however that same stupid slight miss is still there.
The miss is a simple lope noticed in the idle roughly every two cycles, which leads me to believe that it is in the injector wiring to the ECU, or something that can only effect one cylinder. The miss seems to dissapear at higher RPM's, but i do believe was the underlying cause of the engine destruction i saw back in september.
Any insight you guys can provide for me as to the reasoning behind this miss would be greatly appreciated, as i am rather clueless as to what is causing it, and rebuilding engines is rather costly and time consuming to do more than once a year :?
thanks guys !,
take care.
I acquired the car roughly 3 years ago, a 1984 300zx Turbo AE. Three years ago the first thing i did was replace the timing belt and attempted to start the motor. The engine ran rough, but it ran. not only was the belt replaced but the tensioner as well. Now roughly a year ago i discovered the belt had been off by one tooth for roughly one season of auto crossing, causing me to not be able to properly set the timing with a timing light.
Once i had fixed the timing belt, the engine felt much stronger, but still had a miss to it. So i replaced the spark plug wires, spark plugs, rotor, and cap. The injector recall was also done when the engine first fired up leaving me with new injectors. The way the harness is still laid out though, i am led to believe that the dealership did not rewire the injectors to batch fire but left them as is.
Back in September of this year, driving down the highway, the engine began bogging down really badly, and running like complete ass at low RPM's and would not idle.
What had happened is the engine had run lean and caused a good portion of the edge of the piston to melt away, and leave 0 compression in that cylinder at lower RPM's and at idle.
I have now rebuilt the engine using an NA block i have, and have left everything stock on the engine.
While the injectors were out i eliminated them as a potential cause for the miss, and engine destruction by placing them on a pulse machine, on which i could set a certain injector pulse, and run a controlled amount of fuel through the injectors. Each injector delivered the identical amount of fuel with a perfect spray pattern.
This past weekend i just got the engine re-installed in the car, and fired up ( Great easter weekend for me ) however that same stupid slight miss is still there.
The miss is a simple lope noticed in the idle roughly every two cycles, which leads me to believe that it is in the injector wiring to the ECU, or something that can only effect one cylinder. The miss seems to dissapear at higher RPM's, but i do believe was the underlying cause of the engine destruction i saw back in september.
Any insight you guys can provide for me as to the reasoning behind this miss would be greatly appreciated, as i am rather clueless as to what is causing it, and rebuilding engines is rather costly and time consuming to do more than once a year :?
thanks guys !,
take care.
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