FZJ80 - Multiple misfires cant locate source - please help

[dyorkey]

Hi All, hopefully someone can help me chase this gremlin down.

Yesterday my LX450, had a misfile in cylinder 6, had to flatbed home.

Current status. Just did engine rebuild. New rings, bearings, head was rebuilt by machine shop. Rebuilt with all toyota parts, except cometic head gasket. New distributor plugs etc...

Ran the engine for about 270 miles without issue. I just did an oil change to get all of the assembly lube out and replaced the battery that was failing two days ago. I put some seafoam in the gas tank and in the crank case at the same time.

Yesterday had a misfire in cylinder 6 had to flatbed it home. This morning I tore up the intake manifold and changed out the injector on cylinder 6, but there was no change. I switched the plug in cylinder 6 with the one in cylinder 5 (vice versa), to see if it was a bad plug. Then cylinder 5 started to misfire after a little driving. I replaced the plug in cylinder 5 and all seemed to be working fine. Drove the car about 20 miles and then cylinder 2 started misfiring. Tried to swap the plug but no change.

Any ideas???

 

[Kernal]

I have to ask, why put Seafoam in an engine (oil and fuel) that was just rebuilt??

So sounds like random or roaming misfires from one cylinder to another to another??

Check the FSM for the diagnostic work up for misfires.

What engine codes do you get?

 

[CivicFerio]

I have the same random misfire before and it was caused by a deteriorating fusible link. Have you inspected yours?

 

[AussieHJCruza]

What brand spark plug leads do you have and how old?

X2 on the seafoam - ideally not at all, but especially why in the crankcase of a rebuilt engine?

 

[smorkington]

Compression test time