Hey gurus, I need some advice. My 94 SC NAT decided it was going to start misfiring. It's the original 2JZGE w/ 82k miles. The last owner had a 2.5mm HG put on and it's tuned with AEM v1. Internally, I believe it's a stock engine. I heard a slight misfire cruising on the freeway last month so I parked it, thinking it was ignition related. I bought new wires/plugs, disty cap & rotor but haven't installed them because the last time I started it there was a solid misfire with light tapping, kinda sounds like valve slap. The misfire sounds like one cylinder is dead. I keep seeing a debate over if the 2JZGE is a non-interference or not, what's the verdict?

I've never tore open a 2J so I'm hoping some of you can help me with a strategic attack rather than just ripping the top end apart. My suspicion is head gasket, a dropped valve, or ignition issues (wires/plugs/disty). Tell me if this plan is a good start:
• Replace disty cap & rotor and check for misifre
• Remove the IM/TB and inspect the plugs
• Do a compression check
• If nothing is visibly wrong, put new plugs & wires in and put back together (praying for a miracle)

HOPEFULLY the compression check comes back OK, otherwise I'll know more. But if there is a head or valve issue, is there anything I should be doing with the intake still in tact? It's been a hot minute since I've done engine work so any advice would be HUGELY appreciated.

 

In all honesty, I would bet that it is most likely from something ignition related. Make sure to gap your plugs correctly and that they are 1 step colder plugs since you are boosting. If you start the car at night with the spark plug cover off you might be able to see some arching which would indicate the ignition components are wearing. Your plan of attack seems correct and in order. Pay attention to see if there is oil or water in the plug wells as that is a known thing to happen to many jz motors. Might just be a valve cover gasket or someone over zealous when cleaning the engine bay if you find oil or liquid in the wells. The only thing I would add is to check that your harness isn't chaffed or separating as they get brittle over time with heat.

As for interference or not. The GE non-vvti is a non-interference motor; the ge vvti is an interference motor.

good luck!

 

Thanks for the tips. We'll see how this goes around xmas time when I'm off work.

Also noticed you're in Ohio. I'm up in the Akron area and have literally seen less than 10 SC3's. Seems like these cars are becoming more rare in this area every day.