I just bought my 96 Cobra with a Nitrous Express kit already installed. It has a bottle warmer and a BMN Racing window switch. The window switch is said to be set, by the previous owner who set it up, to fire after 3200rpm, and shut off at 6800 rpm with a 1st gear lockout.

There was some confusion about the switches for the bottle warmer and for arming the system etc, but that's beside the point I guess. I was on a on-ramp at night in a rural area. I ran through 2nd, never at full throttle. When I shifted to 3rd I was at 2500 rpms and mashed the pedal.

As soon as I mashed the pedal there was a loud explosion from under the hood, a big puff of white smoke and the engine quit. I was afraid the engine was blown, but fortunately not so. However, the car will not idle now. It runs out fine and makes plenty of power. Obviously, there is a problem with the window switch for allowing the nitrous to fire at 2500 rpms. However, my main concern now is the reason the car won't idle.

Does anyone have any ideas? I don't know what other information would be helpful to include, so please ask.

Thanks!

 

Sounds like a nitrous backfire and you likely have a hole somewhere in your intake manifold and that's why your car will not idle. You shouldn't be driving it. If the manifold is busted, you don't want pieces falling down into it.

 

u could have also melted ur plugs if u were still running stockspark plugs with the stock gap....
last night, a guy on my team blew his trans am ls1 up witha 150 shot... =( it sucked soo bad. we retrieved pieces of his block, as well a smashed oil filter from the street that he blew it up. he was soo pissed!!!! and im really not sure y it blew. it was tuned for the nitrous, and he was running propper plugs and everything! poor ls1!

 

A guy on your 'team'? Interesting.

I think since it cleans out and runs okay when he gets in the throttle would tell me there is a vacuum leak somewhere, like a pretty hole in the manifold somewhere rather than a melted plug. [8D]

 

Perhaps a bent throttle plate? I would think that with a hole in the manifold the car would be completely undrivable and throwing codes. If there was a backfire I could easily see the plate itself being bent to where it lets in so much air the IAC can't compensate enough andwon't idle but at regular drivng speeds it'd be fine.

 

yeah, our team website is http://teamhavocaz.com

 

damn. that. sucks.

 

Okay... well, when I drove it... I only drove it home. It was dark, so I couldn't do a proper inspection. The next morning when I couldn't get it to idle, I left it alone and waited until I had time to look. I took a look tonightand sure enough, there was a big hole in the side of the intake..... where a hose had been blown off!

The hose runs from the intake to the air cleaner duct. Reconnected it, works fine. I'm putting my RX-7 up for sale and the N2O kit from my Cobra, gonna just buy 2001 heads, intake, cams... that kinda thing I think.