I am working on a 1998 Toyota 4-Runner. I changed

This site and video will help you find the cylinder you are looking for and how to change your plugs.
Fig. 5VZ-FE engine Firing order: 123456Dis
https://www.autozone.com/repairguides/Toyota-Pick-ups-Land-Cruiser-and-4-Runner-1997-00/FIRING-ORDERS/FIRING-ORDERS/_/P-0900c152802618eb

https://www.youtube.com/watch?v=VDBdp8rjYkw

Hi, 1994 4-runner hard-start after 3-4 hrs......All the above are good possibilities and should be checked.....I don't know what changing to E3 means exactly, but if it means changing the spark-plugs, it could be that the plugs are too cold or too hot ....it is probably best to stay with the factory recommended plugs ....some plugs are hot and some are cold ,in case you are not aware of it.......good luck with it....Frankie Don.

I am confused. Does it have a distributor cap, rotor and spark plug wires, or does it have coil packs sitting on top of spark plugs?

first check radiator level if it is full and the heater is working good make sure temp gauge is functioning c orrectly it is most likely the coolant temp sensor but if this is a high milage vehicle and you have owned long time and never changed i would also replace thermostat and check plug to temp sensor forr good conections and good wires

Nowadays, I've seen spark plugs last 100,000 miles. The center electrode in a spark plug will wear down, causing a wider gap between the center electrode and side electrode. This wider gap causes harder starts, and if wear is too excessive, it will cause a no start. Hope this helps, Gary

you have fuel pressure problems

yes!! all oil changes should! involve a filter change too! just that dealships high jack you on over priced parts ! and labor they always have and always will

Follow the plug wires to the location of the plugs. You will need swivel scokets or sometime called wobble sockets to get to where there located and long extentions, plus a lot of time!!!!

They are under the plenum. Hard to get to unless you remove the plenum.

contact your local Autozone parts store and they can give you a print out for free.