Ok in theory this cant exactly be given a answer since its more of a try and prove concept but whoever puts me in the right direction will receive $10 through paypal.

Two days ago I was driving around with my father,I decided to show him what my car would do. I shift through first and punch it in second,shifted to third and loss all power. Great my wastegate **** the bed and the boost spike caused a weld on my manifold to crack. Drove home and noticed the car was idling around 3krpm :0

Took the manifold off and tig'd the crack and put it back on. Started it and the idle was still sitting around 3krpm. It is likely I may have missed a spot,but none the less.


I have sprayed the entire intake manifold with started fluid looking for vacuum leaks. Disconnected all vacuum lines one by one and plugged them with my finger. I checked the AFR and it was still ideal. I disconncted the charge piping and put my hand over the throttle body,the car shut off as it were suppose too. I tried to loosen the idle adjusting screw under the throttle plate and still got nothing.


From the signs I have a vacuum leak but I am having no luck at all finding it,and I seriously ran my finger across the entire manifold looking and listening for a change.





If anyone can shed some light on the situation please do,again who's ever response puts me in the path of solving the problem will kindly receive compensation.

 

iacv stuck open? what engine management? can you make adjustments yoru self to help diagnose? Popped HG possibly, what did the boost spike to and what is it tuned to? Could be many things. What map sensor are you running?

 

pcv valve, or iacv bent throttle plate

 

Well I didn have much time tonight to do anything I tried the more accessible things, I unplugged the IACV and didnt notice a idle drop,just fluctiation. Im going to take the IACV tomorrow as well as the throttle body. I just think its really really strange for this to happen all because of the manifold.


Its in chrome pro spiked to 14/15 while im running 8 and on stock map. I checked the oil and it had no froath as well as the coolant was not bubbling.

 

LOL those were FIRST initial thoughts!

 

Throttle plate not closing all the way? maybe a warn out return spring on the tb

 

Could have damaged the map sensor with a sudden spike in bost pressure. there good for 10 psi and you can run a few more psi on them but i am thinking the quick spike to 15 psi on the astock map sensor could have damaged it is that possible? i know a bad map can cause all sorts of problems but still be driveable or just completely not be driveable

 

3000 rpm gotta b a vacuum leak.has to b getting the extra air from some place.

unplugging the iacv wont fix it if it is stuck open

block it off instead

sounds like to me ur throttle bodie i had a friend of mine mess his up n couldn't tell but the throttle plate was bent cause he is a noob and sprayed the nos while the car was off by mistake (i was like what was that) then bang i took a s@#$ **** my pants saw my life flash n all ,he blew crap up but no signs till he started it

so check plate

 

if its on crome pro you should have a boost cut setting. since your running a stock map and on 8 lbs i would of set it at 10 lbs which you should probably do if its not. either way the stock map will cut it at 10. how do you know it spiked to exactly 14/15.

for more info what motor is this? and what car is it in?

 

i dought that it is a vacuum leak. he said when he blocked off the tb it died, if there was a vacuum leak large enough to cause that high of an idle the engine would have kept running.

 

Exactly.

I highly doubt it the throttle plate,could be wrong but when i sprayed out the throttle body ports as well as the carbon deposits around the plate and a puddle formed untill I opened the throttle. I will check it more throughly tomorrow though.


I have replaced the map,and I know it spiked from 13-15 for after I re-welded the manifold I went and drove it and watched the boost gauge.


Im agreeing with the IACV, Ill plug off the port from the inside of the throttle body and hopefully that will be the problem,if so the first responder gets paypal'd

 

i know you said you checked all of the vacumm lines, but you didnt say you checked the throttle body, see if the gasket blew. Also i dont know if your motor has one, but check the ficv. Its right under the trottle body, there is a plastic white ring inside that will come losse and cause high idle, all you need to do is screw it back in tight, This exact thing happened to my buddies car. If you need more help finding the ficv pm me and i can go into more detail. Hope this helps

 

if you see the boost gauge peg to that doesnt mean its seeing that. specially if its a needle gauge. and not all gauges are accurate anyway. only way to really tell is by datalogging.

you check your wg and vac line to it? bov too?

 

if the throtle plate is a lil bent and u block off the throttle bodie with ur hand ten ur hand will b the new restriction between the engine intake and the atmosphere not the throttle plate now if he blocks off all other vac ports and no change either theres a crack in manifold or plate

short puttin hand over throttle bodie proves nothing since thats where all the vac is comin from

 

IACV was the problem,its not stuck open I verified this by taking it off,literally having the engine running and inspecting the IACV. The plunger its self is just leaking,tried cleaning and no result. Something is just obstructing the seat of the seal and without the special pentagon shaped tool to remove the retainer screw I cant take it apart to work,so a replacement has been tracked.



Payment sent,thanks for everyones input,better luck next time

 

so does that mean every 1 who mentioned the iacv gets 10 bucks? LOL

 

haha first correct answer wins

 

ahh ok I changed out the IACV and it didnt help. The IACV port in the inside of the throttle body outside of the throttle plate is drawing a constant flow of vacuum.

 

Do you have an FITV valve? Have you checked it yet?

 

Yes,I do I actually took one of a throttle body I had in the garage last night for me to put on when I get off work today.

 

Ok, before you put it on, take the cap on the end and you will se a plastic ring. Make sure that the ring is screwed in tight. Let me know if it works out for ya.

 

Any word on the fitv?