First post to Mazdas247 Forum.
I rebuilt a 2.0L FS-DE engine with new rings, bearings, valve stem seals, valve grinding, seals, gaskets, timing belt, idlers, water pump. It has good dry compression at 150psi in each cylinder. However, I cannot get the new motor to idle for more than a minute without surging in RPM, then shaking violently at low RPM, and eventually stalling. No check engine light, battery light, or oil pressure light.
The motor has proper oil level, good spark, and is receiving fuel. I confirmed by unplugging and re-inserting the electric connector to each fuel injector. When I remove a fuel injector connector, the idle worsens until i plug the connector back in. The battery is also new and has sufficient charge and re-charges with electricity from the alternator.
This is the second 2.0L FS-DE rebuild I have done for a Protege, however the first one ran flawlessly. I have not disassembled or replaced the variable intake chamber, throttle body, PCV, EGR, or IAC, and this engine did run before I took it apart. It was rebuilt due to excessive oil consumption.
I have tried the following. All were red herrings.
-swap fuel rail and injectors
-swap knock sensor
-swap coil packs
-new spark plugs. Cylinders 1 2 and 3 have black soot on them while cylinder 4 is totally clean. However idle worsens if fuel injector to cylinder 4 is removed. Therefore there must be some combustion taking place in cylinder 4?
-cannot find any vacuum leaks
I have access to a complete duplicate set of parts from a Protege5 that threw a rod. However it would be nice to use some methodology here before swapping parts in desperation. Any help is greatly appreciated! Thanks
I rebuilt a 2.0L FS-DE engine with new rings, bearings, valve stem seals, valve grinding, seals, gaskets, timing belt, idlers, water pump. It has good dry compression at 150psi in each cylinder. However, I cannot get the new motor to idle for more than a minute without surging in RPM, then shaking violently at low RPM, and eventually stalling. No check engine light, battery light, or oil pressure light.
The motor has proper oil level, good spark, and is receiving fuel. I confirmed by unplugging and re-inserting the electric connector to each fuel injector. When I remove a fuel injector connector, the idle worsens until i plug the connector back in. The battery is also new and has sufficient charge and re-charges with electricity from the alternator.
This is the second 2.0L FS-DE rebuild I have done for a Protege, however the first one ran flawlessly. I have not disassembled or replaced the variable intake chamber, throttle body, PCV, EGR, or IAC, and this engine did run before I took it apart. It was rebuilt due to excessive oil consumption.
I have tried the following. All were red herrings.
-swap fuel rail and injectors
-swap knock sensor
-swap coil packs
-new spark plugs. Cylinders 1 2 and 3 have black soot on them while cylinder 4 is totally clean. However idle worsens if fuel injector to cylinder 4 is removed. Therefore there must be some combustion taking place in cylinder 4?
-cannot find any vacuum leaks
I have access to a complete duplicate set of parts from a Protege5 that threw a rod. However it would be nice to use some methodology here before swapping parts in desperation. Any help is greatly appreciated! Thanks
