low boost miss(powerlogger file)

[blackgn1]

I have a low boost miss. New since the exhaust was replaced. Really free up the flow. I'm thinking this is boost surge. Saw a little knock. I am most sure it is false. I don't have a knock problem....always runs fat! What do you guys think? Interesting how big exhaust needs wastegate hole porting and may cause surge. Proves the need for free flowing exhaust.

 

[Rafs-T-Type]

you correction stuck at 25% doesn't sound too good , your AFR crazy rich although is doesn't seem like the wideband is reading since it never moved much...fuel pressure too high maybe? You're TPS is way out of whack then again it doesn't seem like you went WOT

 

[blackgn1]

Never went WOT. Here's a WOT run just after the low boost run. No wideband yet. It's coming next.:biggrin: I only logged to where the missing showed up. Didn't want any extra log exept where the problem(missing) was.

 

[BobbyBuick]

Tune looks pretty good to me.Check your coil tower terminals grounds on engine is coil bracket tight ,plugs and wires &coil packs are most common for a miss .i have seen corroded towers on coil cause some bad missing

 

[jasjamz]

maybe it picked up valvetrain noise or the drone harmonics of the exhaust, Looks all good to me but it must be something because its repeatable.:frown:

 

[blackgn1]

I too thought the tune was decent. I'm going to go through everything when I get done working on the 87 GN I have here for major work. I've got to get this other car finished. It needs lots of attention.:biggrin:

 

[Boost231]

ohm the plug wires, my car started doing that as well. after switching all the expensive stuff like coil and module, it was a damn plug wire.

 

[mikestertwo]

Kind of strange...don't see any evidence of a miss in the log. Normally you would see the O2's spike negative if the ignition was breaking down. The tune looks pretty decent.

 

[blackgn1]

I'm leaning toward compressor surge. Really haven't tried to tune. I'm going to pull some parts off(plug wires,ect) and check a little. Going to the track this weekend to start putting a little timing and boost to it. Doesn't act up from a launch to wot. Just when I go to part throttle a sit there.