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

[Travis89Turbo]

Originally Posted by pwpanas

If the #6 valves are bent, you could get 4 new valves, seat them with lapping compound, and then re-shim just those four buckets. *shrug* just brainstorming ... like you said, it's a good time to try options since you're at the point where the engine may have to come out anyway.

Well here's where it gets even trickier. I was doin the leak down on the wrong stroke. I turned engine 180 and then leakage was in the 30s?? No blowby past the valves but some out of the bottom end past rings. The motor hasn't even ran enough for the new rings on 6 to seat. So now I don't think its a valve issue anymore. Lol. This dang thing.. I'm determined to figure it out.

What I did last night is pulled all the turbo equipment off and put my NA header back on with the ECU's Narrow band O2 sensors wired into the front bank. And then My AEM wideband in the rear bank. And wouldn't you know it. Ran perfect. Doesn't skip a beat or run rough at all. And like I was figuring the rear bank is running just slightly rich 13.4 vs before issue idle was about 14.5. I was able to run the engine up to operating temp hoping to help seat the new rings. Although I found my brand new cam seals are leaking like crazy so I am addressing that issue first today.. And I mean leaking bad. Wondering if I blew them out with leak down test? But not a big deal to change.

So what I am goin to do to for a more permanent fix is weld the o2 sensor bung into my number 1 cyl. Pipe on my turbo mani pre turbo to run my ecu. I got thinkin about tuning after that and figured the best way to do it accurately (except for 6) is to weld an additional o2 bung in either 1 or 2 for my wide band. Allowing me to tune accurately to 5 cylinders and 6 be slightly rich due to lower compression which may go up with some break in. Although it will technically only be tuning to one cylinder but the others are within a few psi of eachother and the low amount of boost/power I am aiming for and just daily driving it not beating it up I believe it should work.

Then the thought of passing the emissions smog test. Luckily its obd1 so its the sniffer. How I plan on makin it pass is with a separate tune I will add only for smog and load it to the ecu at the smog parking lot. Is move my wideband to the downpipe after turbo and de fuel the other cylinders to make My exhaust fall within smog limits. What do u think? To pass smog based off other vehicles I have tuned is around 14-14.7


I will be doin tune with MAP.ECU1 with built in map sensor and runnig an IAT sensor. Deleting MAF.