Misfire under boost??

[The Juggernaut]

Reman 7M GTE
57 trim ct26
mbc set to 10 psi
3 inch exhaust turbo back

I just installed a remanufactured 7mgte and took it out for a test drive today. I was getting on the highway and it felt quite underpowered so I gave it some more gas. I heard the turbo start spooling but kept waiting for it to actually do something. It felt like all it did was make noise, but that's not all. It sounded like it was misfiring while it was trying to spool up. I couldn't find any vacuum leaks. What gives?

This only happens under boost. If I stay out of it, it runs fantastic. Idle is solid, timing is spot on.

 

[MDCmotorsports]

Boost leak.

 

[The Juggernaut]

Care to elaborate?

*EDIT*

Never mind, found some info after searching. I'll look into it tomorrow.

 

[pnutcar]

Its the plug gap lol

I didn't know you were on here... gotta bring that bad boy out sometime when we're meeting...

 

[The Juggernaut]

Yea I know man. As soon as I get the kinks worked out I definitely will be. Would like to get to know some more of you guys. Anyway, plug gap is set at .038. Going to buy new plugs tomorrow.

 

[WhtMa71]

Gap should be way smaller than that. .031 is stock iirc.
I have mine at .028 to keep from misfiring.

 

[The Juggernaut]

Yes, stock is .031. The TSRM says .038 is the max. I'm going to pick some new plugs up sometime before Monday afternoon and throw them in and hope that solves the issue.

Recommendations on plugs? The fanciest NGK's money can buy?

 

[jdub]

Nope - NGK copper plugs...the downside is you will have to change them more often.

 

[The Juggernaut]

Ok, I replaced the plugs. The new ones are NGK Iridiums gapped at around .028. This got rid of the misfire, but it still isn't boosting right. We hooked it up to a smoke machine and found a pretty big leak on the intake where it clamps to the turbo inlet. We tried to repair it the best we could for the time being but it will need to be replaced. I took it out for a drive after that and it felt better but still isn't there yet. I'd say it went from 20% to maybe 50%. There were a couple very small leaks that we saw that we couldn't do much about (the car had some shitty couplers on it) so I'm going to fix those and see what happens.

It is throwing a code though, a 52. A knock sensor code (sorry, forgot to include this in the original post, I forgot all about it) I broke the plug on the old knock sensor and bought a used one from SupraRacer. He told me he pulled it off an old engine and knew it worked. Could this code be causing the boost issue? Or is it a combo of these little leaks?

It FEELS like it's still because of a leak somewhere, the pull I normally feel when it spools up is kind of sporadic. It won't pull at all, then it will start to feel like it is going to and then stops. Suggestions?

 

[jdub]

Code 52 will cause the ECU to significantly pull timing and the car will feel like you describe. It's usually a wiring problem...Shaeff sells a re-wire kit...shoot him a PM.

Those leaks are not helping either

 

[WhtMa71]

Fix any codes you have and then make a boost leak tester and use it!