Recently tryed swapping out upper portion of manifold on a f20b to convert the iacv to the h22 usdm. After doing so i had issues with vacume lines. I got all the vacume lines finnaly planned out in a working order, but now the car does not wanna idol when cold. when driving it also sounds like a all motor blow off valve when letting off throttle at higher rpms. Ive came to believe its the intake manifold gasket for the upper plenum i took off. Older honda techs i work with said u can reuse the gasket, but i believe im in a situation where it was more unlevel then i though. So when cold doesnt wanna idol till warmed up(have to keep foot on throttle),higher rpms sounds like a all motor blow off valve when letting off throttle and releasing vacumed air, 1100-2k rpms when giving throttle it slowly surges up. giving those factors does it sound like the mani gasket is the issue, or still could be vacume line issues?

 

we cant tell you for sure, but it definitely sounds like a vacuum leak.

and please keep these kind of problems out of the all motor forum. Your leak has nothing to do with all motor performance.

 

Its not related to turbo, or other forced induction, nor one type of car in particular, so logicly it would be related to the all motor forum being its a N/A issue. And i Quote:The purpose of this forum is for technical discussion of all things involving naturally aspirated Honda engines. /end quote. And to be even really technical the f20b is a modded h22 from factory : ). But anywho the manifold gasket seems to be the culprit, so it shall be apart again tonight once more...

 

the whole forum is technical related. your post has nothing about building an engine, picking cams...etc.

questions like these are what the model specific forums are for.

 

Its not a platform specific question, its a engine specific question, hence why i didnt place it in prelude forum to start. If we are only supposed to talk about engine internals and bolts on's that are not related to forced induction then please state in policy forum.
Quote:The purpose of this forum is for technical discussion of all things involving naturally aspirated Honda engines. /end quote

To me diag problems involving a intake manifold change, would suit this category.

And yes i do like to nicely argue : ) in no means are these shots at ya by the way.

 

look under the title of the All Motor forum:

Discuss All-Motor PERFORMANCE

I'm not going to continue this discussion of where threads need to be. I am the moderator, you are the regular member. I know where threads need to go and I will do what I think is necessary as that is the reason i was brought on as a moderator.

You have a vacuum leak. Fix it.