strange idle problem.... cant put my finger on it...
 

ok so ill start my car and it will idle at around 1000 rpm on a cold motor, and when i pull out of my garage it jumps to 1500 like it should. but when i come to a complete stop it drops down to 1000 again. the same happens on when the motor is at operating temp.

the car is a civic ex coupe gsr OBD1 t3/t04e 450cc on a basemap from http://www.-------------/.

i just replaced the iacv for a brand new one, so i nkow thats not the problem. ALSO, when i drive, i will decellerate at like 3500 rpm's and the car will backfire canstantly and my wideband reads 18:1. at wot it reads about 11.4 so thats good for a basemap. i just dont understand why it backfires like that and why my idle jumps up to 1500 when i am moving and back to 1000 when im standing still.

also on my boost guage it reads from 23-24 vaccum and it used to read 26 so maybe it is a vaccum leak??? could a vaccum leak cause this???

one last thing, i have an 11lbs spring in my 38mm tial, and it only gets up to 8 psi for some reason... i dont understand that either. all couplers are tight, no cracks in then, intercooler is brand new, ic piping is new. i have a greddy type s bov knock off but im not sure if that is leaking. also i used new gaskets except for where the turbo connects to the mani, i just used gasket maker stuff. you think the heat was to much and just deteriated (spelling) the gasket maker stuff into the turbo and out my exhaust???

so i think i have a vaccum leak, so im gonna try to find that and fix it, but would that also be the reason why im only at 8 pounds instead of 11??? again i have an 11lbs spring (big and red)

thanks for the help and replys
regards,
MIke

Re: strange idle problem.... cant put my finger on it...
 

sounds like a basemap, and your car needing a tune bad!!

It depends where youre getting the boost source from for you w/g. if its from the compressor housing thats probably why youre only seeing 8lbs, tap into your i/m and that should fix that issue.

then you have the gasket missing in between the mani and turbo, which is probably going to if not already cause spool issues. get all of that fixed and you should be golden

Re: strange idle problem.... cant put my finger on it...
 

its tapped from my fuel pressure reg.

yeah, a tune is next on my schedual. thanks for the help!!

Re: strange idle problem.... cant put my finger on it...
 

Yes that exhaust leak will cause it to not spool to it's full potential, which may be why you start running rich on the basemap. Where does it start to build boost? You need to fix that leak between the mani and the turbo. Your turbo will try and make those 11psi or die trying, so it will spin it's heart out trying to make 11psi and you could fry the turbo potentially. Does it hold steady at 8psi or start growing slowly in the upper gears?

Re: strange idle problem.... cant put my finger on it...
 

im gonna fix that this week hopefully. it read 8 pounds, and kinda jumps from 8-9 like it wants to go higher.

how could you explain the backfiring when i decellerate then?? just the basemap i am on?? when i am at part throttle my A/f is around 12.3:1 so i know that is way to rich. could that be it?? or just a vaccum leak?? im still stumped on that and why my car will idle at 1500 when i am moving, but come to a stop and it drops to 1000.

thanks again
regards,
Mike

also i noticed, that when i drive my car, turn it off.... come back 20 mins later, it starts fine, then when i give it a little gas, it starts to roam between like 200 at 1000 and it cant find a place to idle. it died on me one time when i was going to work like that, idle got to low and just died

Re: strange idle problem.... cant put my finger on it...
 

Actually the basemap may be fine the rich AFR's may be due to the extra air from the vaccum leak.

Re: strange idle problem.... cant put my finger on it...
 

so those are all signs or a vaccum leak you think???