i started my car up today and after about 3-5 mins of it sittign there and idling my downpipe was glowing. is it normal to have this at idle without havign to drive the car, or is my main cat plugged up. my boost pattern is 12..8..10

 

someone else here had a similar question. My guess is that during idle, especially upon cold startup, the motor will naturally run rich. The airpump injects more oxygen into the exhaust to help burn up excess gas. Supposedly this causes the DP to glow.

 

Air from the airpump gets injected past the downpipe, into the main catalytic converter.

Was the engine started from being cold, or driven and stopped then restarted?

Seems like there are some other issues going on here.

 

Looks like you are running lean man. Excess gas burning in the exhaust causes the pipe where it is igniting, to glow! Hopefully it is nothing serious. Check your A/F ratio. Find someone with a Wideband O2 sensor and fine tune your ratios throughout your RPM range. It will prolly stop this glowing..and free up plenty of HP.

 

it was started from being cold and liek i said was glowing shortly after, i donno anyone with a wideband o2 sensor. anythign else i can do ? car is stock thats the only mod, dwonpipe...

 

Air is Injectd BOTH at the Exhaust Ports (Port Air) AND/OR into the Primary Catalyst - The PORT Air is injected during the Accelerated Warmup System (AWS) cycle to help the PRE CAT get up to temp.

KAHREN:

TO me it does sound like an Over Rich condition during AWS. With a DOWNPIPE you can either disable the AWS as it is no longer needed (its function is to heat up the PRE CAT) or at least blip the throttle immediately after start up to drop the Idle down from the 3k set by the AWS.

 

hmmm maxpesce, that makes more sence when i started the car wit was faily warm about 50 degrees teh idle was aroudn 2.5k i bliped it i few tiems then it dropped down to 1.8k so i left it there...AWS is acclerated warm up system? and how do u disable it?

 

Check These sites:


http://www.scuderiaciriani.com/rx7/

http://www.rx7turboturbo.com/robrobinette/

 

I didn't disable my AWS, but what you can do is start it in 1st. gear. This will bypass the AWS....p.s. in regards to running lean, I have an autometer air/fuel gauge. Upon start up, it starts at lean for the first 10 seconds and slowly climbs up to rich and stays there for the next 2 minutes, and then slowly starts to to climb back down to lean as soon as motor starts warming up (at idle)