1059184
Having some difficulties with my rebuilt 4.0. Its in a 89 XJ with automatic trans. and RENIX MPI. Got good compression, but power seems lower than before the rebuild. Engine does not want to fire right up first revolution when trying to start, but eventually fires and runs albeit not as strong as I expected. Starter making a shrieking sound as engine fires, probably needs shims, but I am open to suggestion on that too. Started poking around for problems and found: knock sensor is toast, shattered on reinstall. Spark occurs LATE as evidenced by a visual inspection of timing light flash in relation to high tech finger in spark plug hole #1 TDC test. Upon reinstall of the distributor, I found it very difficult, at least by my standards to get the rotor to point directly at the #1 dist. cap tower. This made me think I had the cam in off 1 tooth. Took timing cover off, everything checked out. But, distributor position also controls injector pulse width right? Pulse width off = engine power altered since injectors opening at wrong time. So, pretty much narrowed it to knock sensor (on order), or possibly the flywheel installed wrong, or a bum cam install. Crank position senor might be reading TDC late if trigger off 1 tooth? This engine has been in a year. Cant remember how that trigger wheel is installed. Is it even POSSIBLE to have it off 1 tooth? Seems unlikely if the ring gear bolts go through the trigger wheel also. So, take your best guess!! :-? PS Is it possible I was sold an HO cam for my non HO motor? Would it still fit my block?[addsig]
Having some difficulties with my rebuilt 4.0. Its in a 89 XJ with automatic trans. and RENIX MPI. Got good compression, but power seems lower than before the rebuild. Engine does not want to fire right up first revolution when trying to start, but eventually fires and runs albeit not as strong as I expected. Starter making a shrieking sound as engine fires, probably needs shims, but I am open to suggestion on that too. Started poking around for problems and found: knock sensor is toast, shattered on reinstall. Spark occurs LATE as evidenced by a visual inspection of timing light flash in relation to high tech finger in spark plug hole #1 TDC test. Upon reinstall of the distributor, I found it very difficult, at least by my standards to get the rotor to point directly at the #1 dist. cap tower. This made me think I had the cam in off 1 tooth. Took timing cover off, everything checked out. But, distributor position also controls injector pulse width right? Pulse width off = engine power altered since injectors opening at wrong time. So, pretty much narrowed it to knock sensor (on order), or possibly the flywheel installed wrong, or a bum cam install. Crank position senor might be reading TDC late if trigger off 1 tooth? This engine has been in a year. Cant remember how that trigger wheel is installed. Is it even POSSIBLE to have it off 1 tooth? Seems unlikely if the ring gear bolts go through the trigger wheel also. So, take your best guess!! :-? PS Is it possible I was sold an HO cam for my non HO motor? Would it still fit my block?[addsig]
