philek9

What should the rpm's be on Idle with a mild street port and 3mm seals done by rotary power? I purchased the car and it idled sporatically (sp?) from 700-900 after its been warmed up. However, I took the car for a smog check today and it failed but the smog guy tried to pass it for me. He adjusted some idle screw and told me this is how the car should idle (1500rpms) Could you guys confirm what the idle rpms should be when fully warmed up? The car sounds a lot better at 1500 rpms than 600-800rpms but not sure if this is right. Let me know.

`sl!mXP

my aggressive street port w. 3mm seals done by rotorsports racing usually idle around 900 rpm but sometimes will idle upwards of 1100rpm.

and it wouldnt even register on the emissions machine.

A ported engine wont pass as easily and wont idle as smoothly, also you can expect to pull in a little less vacuum then a regular engine.

Mr rx-7 tt

iTrader: (5)

You have a couple of issues.

1) Jeff builds a good engine that will idle smooth and pass emissions, so your idle problem is a computer, fuel, TPS or vacuum leak problem.

2) The above issue is probably causing you to fail emmissions.

3) Drive the car over to Jeff on Monday and he will set you straight.

philek9

The smog tech is saying I need to replace the O2 sensor as it's pushing too much fuel and possibly change the CAT. It currently idles at 1500 rpms now where it used to idle at 600-800 before. Should I change this to back to 600-800 before I drive it back to Jeff?

Mr rx-7 tt

iTrader: (5)

Just drive it over to Jeff.

If you end up later needing a cat buy a hi-flow from one of the vendors here.

nocomply24

why would you trust a smog guy with an rx7? you know you can barely trust mazda certified people with that car! take it to whoever did your port and work on engine and ask him...not the smog guy.

yuichiror

iTrader: (1)

Listen to Mr rx-7 tt, he knows what he's talking about.

mono4lamar

iTrader: (32)

yeah listen to mr chris rogers...

Mr.kidD

Im having the same issue. I know it's not a vacuum leak or gasket leak Bkuz I sprayed around with carb cleaner. my engine is also street ported with 3mm seals. it's got 2000 miles. what did this guy Jeff say?

wstrohm

Don't know your car, of course, but good luck assuming "spraying around with carb cleaner" will find all leaks. My near-stock '94 was gradually increasing idle speed over months. Turned out the OEM fiberboard lower LIM gasket was toast. Replaced it with the upgraded S/S gasket and idle went back down to 720 rpm where it should be. Big job (for me) but worth it.

Narfle

iTrader: (16)

800-900
15-20 inHg vacuum

Generally speaking a streetport will idle higher with less vacuum than stock. The more overlap: the higher the stable idle and lower the vacuum.
Also, it will take a while for the engine to break in. The compression and idle should improve over the first 1,000 miles or so.

arghx

iTrader: (3)

Umm quick question.

Did he hook up an inductive clamp to a leading plug wire to get a tach signal? Or did he hook it up to a trailing wire? His machine may not have been reading the tach right. It has to be hooked up to the trailing.

Mr.kidD

yea its got 2,000 miles now. I'm not sure if i mentioned i have a microtech but i do and my bac valve is disabled so i just adjusted the throttle position sensor and my idle is around 1,200rpm which is good for me haha. i'm guessing a lower idle raises emissions because i never noticed the faint exhaust thats now coming out before. i guess thats just how it is with ports but regardless can i get in trouble for this? will a cop see that and stop me??? the smell isn't bad which is weird...