3.0v6 misfire?

Hello! New to the 4Runner family! I just picked up my first Toyota and I’m super excited about it. It’s a 95 4Runner but it’s running rough. I replaced everything in line from the rotor to the spark plugs but I’m getting intermittent spark on #1. The timing mark is also way off almost like the distributor is off a tooth. But I’ve read that there’s an “electric timing adjuster” (sorry I’m not familiar with part/system names) that could be the issue. Can anyone tell me where it’s located and how it’s connected or any other tips/things for me to look into? Thank you in advance.

 

What you are talking about is timing advance. This is automatically handled by the ECU. What you need to do is go to the diagnostic port next to the fuse box and jump the TE1 and E1 terminals with a small wire or paper clip. This puts the ECU into timing mode (it also flashes any check engine codes on the CEL light). When you do this the ECU automatically retards the timing as much as possible allowing you to set your timing. Stock timing on the 3.0 is 10* BTDC. Do all this and hopefully it will correct your misfire problem

 

BKCaspy95,
Toyota FSM's are a great investment for educating yourself in how these OBD1 vehicles work because they are relatively complicated unless your have grown up with this era of automotive history. The distributor doubles as a crank triggering device to the ECM on the 3.0 as well as a classic distributor to send the high voltage from the ignitor/coil to the spark plugs. Kyle11863 has you steered in the right direction as you rotate the distributor to get the timing set to 10° with your timing light on the #1 plug wire. However, be apprised of the fact that if this proves impossible to reconcile with the jumper in place then the three piece design construction of the lower pulley assembly (i.e. Harmonic balancer) may have delaminated if it is original and super old as the inner most pulley with the timing notch in it may have shifted with relation to the hub that is keyed to the crankshaft. It can happen when the rubber dampening layer finally breaks down and the two innermost pulleys will slip on the hub with the rubber isolation layer deaminating and will sometimes chirp when the accessories like the alternator is pulling full charge after an engine start. The outer third pulley is screwed directly to the hub and therefore cannot slip which makes it difficult to understand that his can be happening to the inner two pulleys. As for misfires other things could be the knock sensor or the pigtail wire harness to it has failed. The signal coils may be nearing end of life in the distributor and giving the ECM headaches but I would expect the CEL to have a code. When these coils fail they go open circuit and it will be a no start-situation and the CEL will be flashing or illuminated for sure. Then it is time for a new distributor and time to replace it. Also it is good to know when this misfire is happening because the ECM runs in open loop operation using a fixed algorithm for timing and injector intervals when the engine is cold. After warm up it switches to closed loop mode and then the O2 sensor, knock sensor and the VAFM and TPS will be used by the ECM to regulate emissions and general overall running performance. This is why it is important to burp the coolant system to make sure that the senor is immersed in coolant after replacement. If the thermal sensor in the cooling system at the back of the 3.0 is not working any longer or the wire is bocken/disconnected the ECM will not switch to closed loop and yet other things will switch based on operating temperature and this will lead to crappy acceleration and poor operation of the engine. I strongly urge you to find and download and/or purchase Toyota Factory Service Manuals from eBay if you can find them and are planning on living with the best looking 4Runner Toyota ever made.
Cheerio,
Andrew