Multi Cylinder Misfire

[jwlane]

I just finished replacing the timing belt, waterpump camshaft seals and front crankshaft seal on my 1996 LS400. All due to the front seal failing and leaving a big puddle of oil in my driveway.

Since everything was apart I decided it was a good time to replace the distributor cap's, rotor button's and plug wires. Now when I start the car I get trouble codes P0300 multi cylinder misfire, P0301 number 1 cylinder misfire, P0302 number 2 cylinder misfire and P0307 number 7 cylinder misfire. It ran fine before replacing everything. The distributor parts were aftermarket Standard Ignition. The rotor button's wern't a snug fit and would fall off until I put the two screws in. The one I took off even when the screws were removed would stay in place on the cam sprocket. I'm thinking there was enough slopiness to cause the misfire problem. If I get some "I told you so's" for not using OEM part it wont't bother me. Anyone else seen this with aftermarket ignition system parts?

[curiousB]

Why not pop back the old rotors and caps just to see if problem goes away. That would at least narrow down your search. Also double check your plug wiring. Maybe you offset the wires... if problem persists maybe you offset the timing belt a notch or two...

[steve2006]

I have heard that it is possible to fit the rotor arms 180 degrees out so make sure this has not happened,also check the passenger side coil lead to the distributor this can be mis routed and trapped causing damage to the wire.