I'm guessing your idle problems started after going VTA? Chances are that's the problem.

Also, setting the idle to 1500 won't fix the idle dip.

 

thats very true.. i bought a TiAL bov so im going to put that on instead of the hks and see if it couldve been leaking.. im also on e85 put that shouldnt affect the dip

 

The problem isn't the BOV, it's the fact that you're VTA. Go back to a recirc'ed setup and chances are you won't have that problem anymore.

 

even though thats the way its tuned? ive always heard if it is tuned to vta properly then it doesnt matter. it still holds all the way through the rpm range other than idle

 

AFAIK unless you're on SD the only way to "tune" for a vta bov is to apply a bunch of band-aid fixes to get around the problem, however you can't go around the fact that you're dumping air that the MAF has already measured and is expecting to stay in the intake system.

 

no.. the problem is hes dumping unmetered air.. so the maf cant compensate for it, because it cant see it anymore. the only way to dump to atmosphere properly is SD.

 

rog, thanks for the help.. getting the car on sd asap then.

 

I had recirc valve when I opened this thread. then changed to vta but problem still remains. changed throttle shaft seals, EGR removed and blanked, did boost leak test, no leaks

wierd

maby MAF needs some cleaning ?

 

How can the air be unmetered if it's already in the intake system? If it's in the intake it had to go through the MAF...

He's dumping metered air that's been measured by the MAF and that the motor is therefore expecting to be there, except it isn't.

 

Having the same issue now. Just installed 1450's. Fuel Trims are at 2 low/-3 mid. Come to a light, put car in nuetral, and the idle jumps between 500 and 1500, afr's will go from 15 to "---" on my UEGO as it passes the readable range.

Also, as a side note, once in awhile upon cold start up it will do the same thing and throw a P0300 CEL; however, this again, is completely random.

Getting very frustrated with it.

 

Had that problem for a very long time on my car and I've just recently managed to get rid of 99% of it. Try playing with your injector scaling and latencies a bit.

 

Will do. I am currently at 1271 scaling for 91 octane, with latencies to get the FT's listed above. Thought about using scaling 1217 then adjust latencies accordingly for FT's and see how that does.

 

Try one or 2 steps higher and lower both on scaling and latencies. My trims were fine but after changing scaling and latencies I had very similar trims but my idle was pretty much fixed. I solved the rest with ISCV adjustments.

 

I tried higher, didnt go so well. Sounded like a machine gun it popped so much. Lol. The ISCV tables is another thing that I have to work on. Not sure it if is just me, but when I click on anything but the lookup table, I dont get anything. The popup box comes up but there is no data, or any boxes that I can change.

 

I can send you my XML for those ISCV tables when I got home tonight if you'd like.