Misfire codes - question about checking Timing (1 Viewer)

[Tbone81]

This weekend my 2000 LX with 150k miles started running rough under light acceleration and the CEL started flashing only under acceleration. The first code was only P0306. I parked it and caught a ride to the soccer game with a friend. 12 hours later I went to pick it up. I cleared the codes and drove home a few miles. Now the LX was running rough at idle and light acceleration. But still the CEL flashes only under light acceleration. When I take foot off the gas the CEL goes off. On the way home I had codes P0300, P0303, P0304, and P0306. At home there was an odd faint smell from the engine bay that I could not identify and did not last long after I shut off the vehicle. Maybe it is just my COVID smell still giving me issues but something did not initially smell right.

Could the CEL slowly blinking under acceleration just be a coil intermittently going bad?

I have a found a cracked fuel vapor hose and will be replacing that. I am going to replace the ignition coils and plugs because I do not know there age. I am also replacing the PCV valve hoses and another PCV valve from Toyota in case the recently replaced one was bad that my mechanic got from the auto parts store.

But my issue/concern is could the timing be causing the issues and how do I easily check the timing. Any direction or link pointing me to an easy method of confirming timing would be appreciated. The TB was changed 200-300 miles ago by a local mechanic due to a failed WP. There was no miss or rough running at the time the TB was first changed out. The mechanic used the Aisin Kit and also swapped out the PCV valve while doing the work and about the same time I cleaned MAF and throttle body.

I am looking for suggestions to review while I am waiting on parts on order that won’t arrive until later this week. I know misfire issues have been discussed before many times but I did not see my exact issue with the flashing CEL going on and off depending on if whether under acceleration or not.

 

[BullElk]

I have had the flashing CEL and one or two of the 300 codes and sometimes just the pending code. What I found on more than one occasion was the ceramic on the firing end of spark plug was cracked. Replaced the plug and it became new again.

I am still pondering if the plugs were duds I got from Amazon.

 

[JunkCrzr89]

But my issue/concern is could the timing be causing the issues and how do I easily check the timing.

Yes, but that’s unlikely with the DTCs you have. If timing was the issue, the entire bank would likely be misfiring.

I agree with @BullElk that your issue sounds more like plugs and/or coil packs being the problem.

 

[2001LC]

I would agree plugs and or coils. If unknown as to when replace, need checking spark plugs for walking-out. Typically we hear a cold engine start up tick, when plugs loose.. As they walk out, combustion gasses cook coils. Coils will misfire, sometimes long before failure.

But whenever a service just done, especially timing belt. I look there first for issues.
Issue such as:
Wire housing block not fully seated.
Cam, crank, oil sending unit wires routed wrong. Rubbing & cutting.
Cam shaft sprocket bolt not torqued.
Tensioner bolts not torque, or it's shipping pin not pulled out.
Vacuum line(s) not connected.
Coolant low.
etc....