Well- just thought I would see if anyone knows.... I bought the car a year ago and this is my first vette. Number one, it has magnaflow exhaust with no catts- every now and then I get some pretty bright white flames pop out the back- usually during shifting, but at any amount of throttle. (mostly when letting off the gas)

The previous owner told me he "had the idle raised"... well- 900-1000 at a stoplight is just too much for me and I felt myself really holding the brakes down just to sit- so I found the idle screw and just turned it till she hummed at around 6-700

I also have numerous known 700r4 issues...... right now she takes way too long to shift from 2-3, but 1-2 could give me whiplash- I'm replacing the converter and installing a new t/v valve and cable, and some firmer valve body springs to help

I was also told it had a mild cam installed (still use the original alum. heads)

Check Engine light comes on interm.- I had it scanned a few times and the stored code always came back as the EGR valve blah blah blah- however recently, code readers seem to not be reading the computer anymore (says its not hooked up or something to that means)

Is this a big deal? Can I be saving more on gas somewhere? I've grown used to it by now, but reading around here I see there is a lot involved with the idle screw and TPS- dirty IAC and things like that... right now she gets 18-20mpg around town (goes all the way down to 8 leaving any light or stop sign, normal driving) and around 28-32 hwy- this close to anyone else?

Should I be looking into anything or is my vette being reasonable?
Thanks a lot
Duke

BTW- I'm not interested in emissions legal (no emissions in my town) but mpg's- a little

So if anyone knows anything about this code reading crap or if there are some electronic sensors or senders I may need to be looking at.... thanks

 

Flames out the tailpipe are typically caused from unburned fuel being ignited.

There are kits you can buy to put this on your car that program the release of unburned fuel into the tailpipe, but it requires a ignition source normally.

Maybe the guy you bought it from has installed one of these.

Good Luck

 

Here is the link to the Exhaust Flamethrower kit if anyone is interested.


http://www.eatmyflames.com/faq.php

 

well, no- i've had the exhaust off a few times doing tranny work- nothing special- it doesn't happen every time- but 75% of the time when I let off she burps some flames- a quick loud pop (not a backfire though) out the back- corvette gods put a sh*t-ton of sensors and electronic dicky-doo's that control all sorts of crap- I just don't know where to start...or if I need to worry at all... just wanna keep her healthy (and my gas fund )

I clean out the intake with some good old-fashoned SeaFoam every now and then- I keep the cold K&N clean- I noticed the exhaust smells... rich- or thick... but no cats so I expect a little more makes it out...

 

Rich would give you the fuel necessary, I just don't know where the ignition source would be.

 

WARNING!!!!!!!!!!!!!!!!!!!

That's not how you adjust the idle. GM covers that screw with a plug for a reason. The process for adjusting the idle is in the archives here......do a quick search. Adjusting it correctly may even cure some of your other woes.

just my .02

 

Sweet, does it look cool at night?

 

With no cats and the idle set up(?) and lord nows what else might be changed (cam?) sounds like the ECM doesn't know just what to do. I went thru a rebuild 87' and did lots of top end work bigger valves, roller rockers, cam, custom intake, injectors and longtube headers no cats no air had a custom chip burnt (PCM for less) and (alot more stuff) then had a couple of the injectors go south and went with a little bigger ones. The car ran ok but still not quite right I found out about a guy down at Festus, Mo. and made arrangements to catch up with him and go thru the chip again. Long story short he worked wonders it runs as some would say scary fast (unbelievable) and the gas milage went up as a plus. He worked on it all day and then burnt the new chip and best $350 I have ever spent. He might be able to take a look and try to figure out whats going on. Drop a PM and I will send you his number so you can reach him. wro87

 

you have more than a couple of problems.
1. you need to properly adjust the idle with the throttle position sensor with the idle air control valve properly positioned.
2. you need to readjust the throttle valve cable on the trans cable on the throttle body on the left side of the engine.
3. you sound like you might have a leaking injector or two,
4. you sound like the check engine light should be on constantly
5. you might have a bad oxygen sensor.
you can probably save your trans by adjusting the TV cable. If you look closely on the left side of the throttle body, you will see there is a funny shaped plastic device on the linkage arm. It has a cable coming out of it,. It has also a white or light gray button sort of.
Engine off.....
If you push the button, and pull the throttle body to full throttle, then let go of the button. then look really close to the black sheath of the cable. you will see a wear mark. Chances are, that that is the real location of that cable, slide the cable to the wear mark, and it should cure your trans problems unless it is too far gone.