Ok lets start from the top,
My buddy and I just finished the Ho mani swap on my 98z. We let it idle for about 20 minutes and i would not go down in idle it would stay at 3500 rpms. We took it out for a test drive and whenever i turn then brake my rpms shoot up to 4500 and stay there. then they go back down. its really weird. Any body else have this problem? any help is appreciated. ,
Tom A and Sean
"Boost tuning"....... have you had your 8 PSI today?
future name of the winter shop!!!
i see you finally got to use that mani huh?
I may run 18s, but I can do your taxes in 10 seconds flat.
probaly a vacum leak
Im a Xbox 360 fanboy...and damn proud of it!!
definately sounds like a vacuum leak
Check the back side (side facing the block) in the lower right. Is your mani hitting that small bolt ? Thats what my problem was, sounds similar to your problem.
PSN ID: Phatchance249
small bolt on the block? or on the mani? we checked all of the vacumm lines. they are good. im gonig to check that bolt thing tommorow its at the garage riht now or id go look at it now.
"Boost tuning"....... have you had your 8 PSI today?
future name of the winter shop!!!
Yeah, it sounds like a vacuum leak based on other threads about this topic. Mine fired up fine right away and except for some sputtering that was cured by a spark plug and spark boot change, it's worked problem free for me since the spring. As for it hitting that bolt, it seemed to get in the way at first and I actually tried to grind off a bit of the rear of the mani (near a threaded hole? But, turns out I was just trying to fit it up at the wrong angle. Once it got in there right, it actually cleared the bolt without issue. Did you use a flange, or did you port match it and just use a gasket? I found the flange and 2 gaskets sealed it up nice right away.
Good luck.
sounds like a vacuum leak
get a can of propane and go around the manifold with it on and see if the idle changes if not the seal on the mani is good. IF you hear a hissing in the engine bay you most likely have a vacuum leak. If you cant find any other problems take it to a shop that has a scanner and see what the idle air control motor steps are at anywhere from 20-60 steps is normal. Did u check if the throttle was closing all the way? maybe something is bound up on the throttle cable. Ive had my intake coupler hit the tb plastic part that holds the cable get stuck. Good luck let us know what happens.
*2012 mazdaspeed3*
when i put mine on it didnt idle at all it went straight to 8k....i ended up taking mine off....but when i put on the stock on it did kinda the same thing as urs....it ended up being a vaccum leak.....r u using the 2.4 TB....if so make sure to plug the Fuel pressure nipple on the TB...
you scratch my ride IMA EAT YO CHILDREN
thanks guys ! everyones input helped and we found a small leak under the throttle body leaking massive air lol problem fixed. she sounds greater then ever
"Boost tuning"....... have you had your 8 PSI today?
future name of the winter shop!!!
