Intermittent miss up to 2k and idle when warm NA-T

[Travis89Turbo]

Update

I switched the o2 sensor to the rear bank and what do ya know it started acting up again stumbling on idle just like before afrs drop lean.

So I ohm'd the injectors they all checked out within limits.

So tomoroow I will be gettin a new leak down tester and an adapter for my compression gauges as I didn't receive it back after I loaned it out.

Fluid levels still look great. No mix in any fluids so I am starting to wonder about my piston rings. ??

[pwpanas]

Originally Posted by Travis89Turbo

Update

I switched the o2 sensor to the rear bank and what do ya know it started acting up again stumbling on idle just like before afrs drop lean.

So I ohm'd the injectors they all checked out within limits.

So tomoroow I will be gettin a new leak down tester and an adapter for my compression gauges as I didn't receive it back after I loaned it out.

Fluid levels still look great. No mix in any fluids so I am starting to wonder about my piston rings. ??

Maybe a silly question, but if it runs great using the O2 sensor to the front bank then maybe the problem is related to the rear O2 sensor (i.e. not anything else like the piston rings)?

[Travis89Turbo]

I used the same o2 sensor for both tests just switched locations with my wideband afr.

I did a pressure check on the intercooler and piping but with the turbo pulled off I couldn't do it through the intake of the turbo yet.

Could still possibly be a clogged injector but the compression test will let me kno that tonight.

If it is rings I won't be rebuilding the GE. The limits are so tight on these motors I don't trust it with just a plasti gauge and don't have any better or special tools for that. So I will be looking into a 2jzgte swap with my single on it and pull the jdm twins. But would much rather not have to do that. Hopefully its not a compression issue in the bottom end. I will keep you posted!

[pwpanas]

Originally Posted by Travis89Turbo

I used the same o2 sensor for both tests just switched locations with my wideband afr...

Okay, but which O2 sensor was the oem ecu using to regulate the a/f curve? Since it ran fine when you flipped the wideband...

1. Originally Posted by Travis89Turbo

   ...I pulled the turbo system off and put the stock na header back on with the sane 4runner dist cap and msd wires. Car runs AMAZING so far it made it all the way to work and didn't skip a beat for the first time in a while!...

2. Originally Posted by Travis89Turbo

   ...I switched the o2 sensor to the rear bank and what do ya know it started acting up again stumbling on idle just like before afrs drop lean...

...then it seems that troubleshooting should focus on something to do with the O2 sensor?

If this is a dumb suggestion, please ignore. It's REALLY hard to provide third-hand advice over the internet...

[Travis89Turbo]

The GE originally had two single wire narrow band o2 sensors from the factory. About 6 months ago I bought an na header that had screw type o2 instead of the 2 bolt so I bought two brand new bocsh screw type o2 sensors. Ran great with no problems.

When I put he turbo and downpipe on I ran the two new o2 sensors. When the problem started o2 sensors were ny first thought so I pulled those two off and exchanged them under warranty. Installed them both and same problem.

The wideband is strictly for my AEM AFR gauge.

The current set up just so u understand how I have it hooked up is my wideband hooked up in one of the banks and then 1 of the new o2 sensors with both o2 sensor wires ran to it. When I have the ecu o2 sensor hooked in the front bank and wideband in the rear the car runs flawlessly. It certainly doesn't feel like im down a cylinder.

When I switch locations of the wideband with the same ecu o2 sensor now in the rear bank still with both wires hooked to it goes lean as soon as I fire it up.

The single wire o2 sensors have less then 15 miles on it.

[Travis89Turbo]

Results= Bad News!

Compression test results done on warm engine. Done 3 times and averaged.

#1- 170
#2-171
#3-171
#4-172
#5- 168
#6- 140----- with oil in cylinder 192.

Lesson learned- never boost an na without thicker headgasket. Even under 5 psi!

[pwpanas]

Originally Posted by Travis89Turbo

Results= Bad News!

Compression test results done on warm engine. Done 3 times and averaged.

#1- 170
#2-171
#3-171
#4-172
#5- 168
#6- 140----- with oil in cylinder 192.

Lesson learned- never boost an na without thicker headgasket. Even under 5 psi!

Gosh sorry to hear that.

Y'know, there still might be a problem with the air:fuel tuning too. Since it actually ran great a few times for you, it's tough to explain that if #6 is broken. Maybe with some heavier weight oil and a new oil filter you could keep troubleshooting - just until you get your shortblock swap squared away? Just a thought - maybe a bad one. *shrug*