ok guys, i've done some searching to find a resolution to my problem... i recirculated my bov, and it has helped quite a bit, but my revs are still dropping below idle after i let off the gas...

i may have a boost leak... is there a simple way to pressurize the system to check for leaks with an air compressor?

also, is there a way to adjust my tps sensor?

how can i check if my IACV is working correctly and how do i clean it out??

thanks in advance...

 

iacv can be taken off and cleaned out with some evaporative cleaner.
TPS- Just replace it. its a cheap way to rule that out (maybe even fix it).
you can pressurize the system by going into boost...hence the *PSI.
easiest way to see if you have a boost leak...go around all the couplers and fittings with Throttle body cleaner...and spray it...if the engine changes RPM rapidly...you found it. Check the charge pipe...right off the turbo. You can also use that TB cleaner on the IACV cleaning.
TIP: If you disconnect the IACV and its acting the same...you know thats not it.

thanks for searching first, i know it doesn't always yield answers.

 

is there an easy way to take off the iacv without taking off the whole intake manifold? i took a look at it today and it seems like a tight fit... i've got pretty small, but i don't wanna get started on something just to find out that it can't be done... if i just unplug the iacv, and the idle doesn't drop... then you're saying the iacv is faulty/needs cleaning? which plug do i unplug?

i've done the method you speak of spraying carb cleaner around the couplings (which you suggested in a previous thread...) and i don't notice any changes... so i'm not sure if the iacv is stuck open, clogged, or whatever....

how do you test if the tps is working correctly? when the harness is plugged in, there's no place to stick the leads for volt meter...

could this be due to my O2 sensor?? the car runs great under load... but just struggles when i let off the gas... this was all exaggerated after i upgraded the turbo to a t28... (i've got a redtop...)

 

what bov you got and how did you recirculate it

 

i've got a hks ssqv and it's recirculated back into the intake....

okay, the revs are dropping in a weird fashion... after i let of the gas, the rpms drop to 1000 and holds for a split second... then drop down to 2-300 then it comes back up... so it's not always dropping down immediately... it hangs at 1000rpms for literally .25 seconds before it drops down further.... anyone know what may be causing this???

 

is your BOV open at idle? if you are recirculating your BOV, it should be. you may need to remove a spring inside your BOV to adjust the vacuum it opens at. ideally, for example, if your idle is between 16-19in/Hg, you want your BOV to start opening at around 12-14in/Hg.

 

i haven't made any changes to the bov besides recirculating it... and it's a newer hks bov that doesn't have the adjustment screw on the back... i'm not sure if i want to open the bov up, cause i really don't know what i'm doing with it....

 

doesnt hks advertise that there bov is not open at idle? i could be wrong but thought i had read that somewere

 

lets see if we cant fix this. Granted there may be a more direct method, but i like the good old 'trial and error' way to fix something.

1. you say you have your BOV recirculated. You may want to elaborate on the method you used to plumb it back into the intake. If the return is too close to the MAF sensor, it may be disturbing it everytime it recircs. This can be fixed my moving the recirc further away from the MAF.

2. You could also remove the recirc hose from the intake and block them both off (take the BOV release/recirc out of the equation) and see if the problem still exists.

3. If you had a boost leak you'd know it on throttle, the car would break up noticeably.

Lastly, when i had an SR, it would drop low RPM's off throttle and require a blip to bring it back up to normal. I got used to doing it over time. It is nice to be able to let the car wind down in 4th gear and shotgun backfire on q.

If you live near USF in tampa, send me a PM. Id be glad to look at the car in some spare time this weekend. Good luck

 

i've got the bov recirculated back to where the stock bov recirculates to on the flex rubber intake tube...

before i put the new turbo on... when i let off the throttle, the revs would go down 1200 rpm and hold there until i stopped... then it would drop down to idle... it now no longer does that... it'll just drop down all the way down to 200 and then come back up to 900rpms... so i'm not sure if it's the TPS that needs adjusting or the IACV that not working correctly, or if my O2 is screwed up...

i'm actually in naples right now, and perhaps in the next few weeks i might be coming back to clearwater.... maybe we can meet up sometime then...