ported intake runners, now it won't idle and runs rough?!
 

Well i just got the car running good, then my ass decides to port the intake after reading about it in the archive. now that i got it all back together and everything it has problems idling (it dies) and it runs rough. everything is hooked up right , could it be a leak if i didn't put the manifold back on right?

That or a vacumn leak.

ok, i'll go over my work again...i think one of the intake gaskets is leaking though

did you put down more sealant when you reinstalled it?

Where in Ohio you from Jones? I am from Toledo originally and my brothers are at U of cincinnati and the other is at Xavier university.

Sounds exactly like a big vacuum leak.
I gauantee you left a hose off somewhere. Probably not just from a small gasket leak unless it's really bad!!! Check for disconnected hoses...

Most times a vacumm leak will make the car idle very high, not stall out....

Is your TPS set correctly.

You may need to adjust you air mixture, being you ported things out.

incorrect my friend.


I had a major vac leak and it would make my car stall out and idle very rough. Trust me I had to re-start my cr about five time on the way to school while this was happening to me. the TPS wold not make your car stall only idle funny or studder.

you might need to turn up the fuel i did when i ported my whole intake...

hahahahahahahaha


WTF are you kidding I run hella rich even with a full exhaust. it is not like he ported the engine.

Go pull a vacuum line and your idle will rise, you had a fuckin massive leak and the cpu couldn't compensate, or you had another problem..

Dpends what vacume line or what vacume leak the engine will react differently. Both of you are right

The idle will rise if it is only a very small leak, and there are NO other leaks at all. This is because the stock idle is a little rich. If, on an S4, the idle mixture screw is set properly, it won't rise.

You have a large vacuum leak.

i've had a small leak and the car stalls cold in the morning... turned out to be a small vac hose disconnected near the firewall side of the UIM

screw it i'm going to try and find a stock S5 UIM, i don't feel like messing with this, my car runs like crap now. i imagine i ported it wrong somewhere, but i'm not trying it again.

Porting it probably WASNt the problem, it was taking all that stuff off and putting it back on. You messed up somewhere, it happens to the best of us.

well i again ordered new gaskets from mazdatrix and i'll follow it closely to make sure everything is hooked up ok, and if doesn't work right then , i might just shoot myself haha

Expecially u Doty.

I porting my SE and had the same problem. I took that manifold off three times looking for vacumn leaks. I finally found that the 10mm bolt on the top front of the throttle body need to be adjusted. Its on the same piece as the OMP rod. Try turning that bolt in until it idles.

A common problem when removing and replacing intake manifolds is not scraping all the old gasket off the mating surfaces (both manifold and engine). The two surfaces must be spotless, or it'll leak. Been there...

The Throttle body hoses sometimes get pinched. Found that out the hard way.:(

for those of you who ported your intake manifold on a t2, did you notice a big difference? How much porting did you do. I have my upper intake manifold totally stripped down for polishing and was thinking about porting it.

Whatever you do you have to port-match it to the lower manifold, so you'd need to remove that too.

Re: ported intake runners, now it won't idle and runs rough?!
 

At what RPM? What is the lowest RPM you could get it to stay running? Does it run well other than the idle?