LIke the subject says, can an Airfoil cause a poor idle condition by blocking the IAC passages??

I've got the weirdest floating idle problem all of a sudden. (intermittant, will idle fine for minutes, then start floating and possibly stall, then idle fine for a bit, then ...)

The SVO injectors may have something to do with it, but the O2 voltage looks kinda normal, I fatted and leaned out the fuel and no difference is made..


-- Joe

 

Check for a vacuum leak from putting the airfoil in, no they don't cause idle problems.

 

On LT1 cars, the answer can be yes if the airfoil is solid (hence obstructing the area behind the airfoil). The area behind the add-on airfoil is connected to the IAC plumbing system.

I don't know if this applies to TPI cars because I don't know if the throttle bodies, and/or IAC plumbing, are the same or not.

Try removing the airfoil. They're only good for a few hp at max rpms anyway. FYI.

 

Hi,

Thanks for the replies, first off.

The reason I added it was because I figured it would help the air entry on my supercharged application. I have no problem removing it..

I also added some bigger injectors, btu the car should run poor if they were at fault. It actually pulls harder.

The reason I asked, is the comp-cams airfoil I used seems to totally block off the IAC passage, so how does it get air to idle?

I guess it could be a million problems,. but I checked over and over again for vaccume leaks, none.. And th einjectors don't seem to leak down, right now I have FP set to 40lbs, but was set to 45, 50, 35, etc, none seem to make a difference.

-- Joe

 

Anesthes,
Some of us on this forum have made our own airfoils and someone else is interested in maybe buying one. It's not too hard. I made my own and it works fine. You just have to make some holes for air to get through for idle. Email me for details if you're interested. BTW, my car is an 89 305 tpi if it makes any difference.

 

If you are burning your own chips try lowering the fuel injector setting a little. The SVO injectors do not seem to run what they are rated at. Do a search and you will find many who have experienced the same problem.

 

I did a few searches, and couldn't find much on a weird idle problem.. I need to get soem prom equipment, I'll prolly buy soon..

Thats a good pulse width for the SV0 injectors??

-- Joe

 

Do a search on SVO injectors. What size did you buy, 24, 26, 30?

If you can get me this info I can give you a good starting point for setting the injectors we may even be able to get by on adjusting the fuel pressure.

 

I'm running the 24#ers..

I'm surprised there is only a problem under idle though... I should prolly reset my TPS and IAC adjustments eh?

-- Joe

 

Well after looking at your combo. I am suprised this is the first problem you have had. That is a great setup! I would leave the TPS stock unless you have no means necessary to alter your chip.
You probably need to bring your idle up wirth the cam heads and super charger. 800-1000 rpm would help. This could easily be done in the chip, but if you do not have the means to do it in the chip you can possibly get around things by adjusting your TB blades and then getting the TPS back to .53 and then set the IAC.
I would also try bringing the fuel pressure up to 45psi. If you could set the injector constant in the chip I would set it at 22 or 21.

 

Think so?? Its been runnign great without any prom mods..

I'll be getting the chip stuff soon.. 45psi without vacume connected eh?

I made a 52MM throttle body but I havn't gotten around to putting it on yet.. I guess I should prolly do that as well.

-- Joe