Problem with the RB... I know tell me something new

[240drift916]

Alright so my RB just crapped out on me the other day, it starts and drives fine under vacuum but as soon as it hits boost it stutters and sounds like its missfiring, boost gauge goes to zero and thats as far as it will climb. I changed plugs and checked for boost leaks, ecu is throwing code 12 maf circuit and code 43 throttle position circuit. The car ran fine ever since I got it and just recently started doing this. My question is, does pulling off both sensors to see if it affects idle and drivability a valid test for the sensors? Because if I pull off the MAF it runs even worse same with the tps. or do i need to test with new ones? Or has anyone ever had this problem before and found another solution? thanks for the help guys. Oh and yes I have been searching day and night since it happened so please try to help instead of telling me to search

[repda916]

i think you answered your own question... you know the problem why not fix it:goyou:

[modestmouse]

I know you said you checked for boost leaks but I think you need to check again. It sounds exactly like a boost problem. Get a system pressurizer if you don't have one already and start checking those couplers! I've seen couplers tear and cause this. They look fine and operate normally when under vacuum but when boost kicks in, they open up and make the engine fall on its face.

[240drift916]

yeah but I tested both sensors and they are good, so yeah I'm gonna pressure test for boost leaks now we shall see what happens

[240drift916]

Update, replaced MAF, did boost leak test had no leaks, reset ecu and still nothing, could something else be wrong that anyone can think of???

[Lozer]

You have a boost leak. oh and chekc to make sure your intake side isnt leaking also. And is you bov recirculated?

[PoorMans180SX]

Check for loose or broken hoses around the intake manifold too.

[240drift916]

yeah but i got the boost leak test done and it came up with no leaks at all, and no my bov vents to the atmosphere

[roboticnissan]

has your bov always vented into the atmosphere?? has your intake piping got a hole somewhere??

[240drift916]

yeah its always vented to the atmosphere and no there were no leaks when i got it tested

[PoorMans180SX]

Well if you're throttle is closed when you do the boost leak test then it won't even detect intake manifold leaks.

[240drift916]

Aw dam I didnt know that, thanks 180 ok I guess back to leak testing, I'll post my progress in a few days mucho appreciated everyone!

[240drift916]

still nothing guys, all lines are sealed, could it be a bad coolant temp sensor? I read a few posts over on NICO (flame suit on) and someone had the same problem, and it was fixed with replacing the cts. I was thinking maybe thats it, but its not throwing a cts code

SR ftw?

[240drift916]

bump anyone?

[AS240]

if you find out, let me know in case my rb decides to do this one day haha
sr < ka < rb lol

[S13RB25DETDRIFTER]

i just had this problem today my RB was running like crap when i shifted to 2nd gear it would backfire like crazy if i full throttle when i open my hood i notice that the internal Wastegate vacuum was off i put it back on and there my power was restored hope this helps

[nyc240sx]

if you have a greddy bov change it that would be your problem if you have a big exhaust housing on the turbo that will stop you from hitting boost too but the bov is what you should look at first