1996 Toyota 4Runner TINY misfiring?

I’ve owned 2 Camry’s, one with. A v6 the other with a four. They both had this problem and both times it was an ignition coil starting to go bad. They can be expensive, but there are online options that worked great for me. I’m still driving the four cylinder Camry. I thought it only had a small misfire but was otherwise OK, but after replacing both coils this thing surprises me. Lots of power again. Never knew the power was kinda gone, but now that it’s back – WOOHOO!

There is always a chance you have a loose electrical connections. Checall ends of all the battery cables. The positive goes from the battery to the alternator, then the starter and sometimes a power distribution block aka underhood fuse block. The negative goes to the chassis and the engine block.

Also, there are ways to bench test a coil, but I’ve found them to be worthless. Why? Because if it has an internal crack, it will sorta close up after its cooled off enough to test. When its mounted near the warm engine, that internal crack will expand causing loss of signal.

This engine has the 3 coils which has a ignition wire running from it to another cylinder correct? You could always swap the coil around with another one. If the misfire moves to the cylinder you swapped the coil to then you know its bad. So for instance, take the coil off of cylinder 3 and move it to cylinder 1. If 1 starts to misfire, its a bad coil. Also pull a plug out when the coils are removed to make sure they look good and not causing your problem.

[quote=”jmf269″ post=146572]So i switched around the coil packs…No difference. Did another diagnostic on it and cylinder 3 is still misfiring.[/quote]

The plug looks ok? Need to make sure you have proper spark at that cylinder. Need to make sure that your fuel system is ok. You said you replaced o-rings but have checked the actual injector? From a quick search, on a cold engine, you should have 14-18 ohms of resistance across the injector. Any more, its bad. If you took off the intake, make sure the gasket is seated properly. Make sure you have proper power and grounds for those items. If all the basics are good (fuel, spark, air) and there are no electrical problems, next would be mechanical. do a leak down test or compression test.

I am not a toyota expert nor do I have extensive knowledge of that particular vehicle. Maybe someone on here does. But for the most part, diagnostics are the same from vehicle to vehicle. If you have access to a service manual, it should tell you how to do those things. Or google it. There is a wealth of info on the internet. It can be something really simple or something complicated.

Since you’ve already swapped the coil packs, have you tried swapping the wires? If you swap the wires and the misfire is in another cylinder, you’ll know its the wire. Also you may want to inspect the spark plug, even if they were recently replaced. I’ve had the ceramic crack on the plugs crack shortly after replacing, thus the gap couldn’t be jumped, causing misfires.

Best regards
-Ryan