sam95transam

Hello all,

I just swapped my intake from an LS6 to a FAST 102/PPS 102 TB from Speed Inc. and, as usual, I now have a problem. When I crank the car up, the rpms immediately jump to about ~2200 rpm then slowly idle down to about 1200 rpm. After it sits for about 30-45 secs, the rpms will begin to slowly climb to as much as 3k before I shut it off. Rpms also tend to increase if I put it in 1st gear.

What I have done to troubleshoot the problem:
1) Sprayed carb cleaner around the base of the intake, as much as the pcv lines as possible to get to. Have not noticed any difference in idle speed as one would expect.
2) Retorqued Intake bolts to ensure proper seal.
3) TPS relearn for the 102 TB.
4) Inspected all vacuum lines to ensure everything is connected.

I know people have swapped these intakes and ran the 102s without a tune, so while I know it indeed needs to be retuned, I feel that there is a bigger problem somewhere.

Any help is greatly appreciated!

Storm Trooper

iTrader: (11)

I have never heard of someone not tuning the car after a 90mm intake install, let alone a 102 (which is even harder to tune). If the car has not been tuned then I am going to assume thats the problem....

jrob56

iTrader: (39)

It should be tuned but I cant imagine not having a tune would cause the issues the OP is having. Did you unhook the battery to kind of reset it all? Try to drive it and let it learn?

sam95transam

My thoughts exactly. I plan on having it tuned as soon as I can, but the problem is that this thing is going to drive TERRIBLE on the way there.

I'll try unhooking the battery though, hadnt thought about that. How long should I unhook it for? 30 secs? 30 mins? I was going to try driving it earlier but I was scared to pull out my driveway on the busy main road

jrob56

iTrader: (39)

Idk I always just go unhook it, and go do something else. By the time I remember it it has been long enough haha. I dont know the minimum but sure 10 mins and your def good.

2000sprayedss

Did you take the intake apart and run a bead of rtv along the back corner? Ive heard of them not being sealed good

sam95transam

I did

Mike Morris

iTrader: (55)

Check the TB for sealing at idle. Make sure the flap closes and opens fully and smoothly and there is no play in it.

My6speedZ

iTrader: (18)

Check your map sensor. If your motor mounts are shitty and worn out when the motor torques it might have knocked it loose.

sam95transam

I had thought about this as well. The 102 TB (as you would expect) fully closed allows much more air in than my old stock P/P did, so it makes complete sense that it would idle higher. I was under the impression that the relearn would compensate for this. I could be completely wrong. Going back to the original post...if this is why it idles higher, what could be causing it to randomly increase idle speed after a short period of time? Just the fact that its untuned?

Sorry if it seems like a noob problem. I've done a couple of intake swaps on cars before but never really had any issues like this. I just want to make sure that when I take it to my tuner that there isn't a problem somewhere that needs to be resolved before tuning can take place.

jrob56

iTrader: (39)

If you dont get to the bottom of it, I would call your tuner and see what he thinks. What maf are you running?

HioSSilver

iTrader: (8)

I had the same problem. Wanna know how I fixed it?

garygnu

how tight is the MAP sensor.

sam95transam

Stock MAF

HiOSSilver:
Sure...but I have a sneaking suspicion I'm about to get rick rolled..

gary:
It isn't SUPER tight. It has a little wiggle in it, but I did put a bolt and a washer on it to keep it tight. I guess its possible that it wiggled loose during the install...

Thanks for your help guys, keep it coming!

sam95transam

Ok, so I went to Advance to get them to run a scan and see what codes it threw. I cranked up the car and it seemed to be running OK minus the fact that its idling at 1300 rpm. Advance was less than a mile away, but when I came back it was a different story. The car seemed to be running OK under load, but when I push the clutch in it goes to about 3000 rpms. Also, it seemed to be driving itself when I wasn't touching the gas and it sounded to me like there was a tick/sucking noise while driving. If I were a betting man, I'd say there is a leak somewhere...I just can't find it ANYWHERE.

PO122 (TPS low voltage)
PO412 (secondary air injection switching valve a circuit)
PO507 (iac system revolutions per minute higher than expected)

Here is some other info that may or may not be useful to you guys..
MAF= 2.45
MAP= 2.4

Going back to my cammed LT1 T/A, my scanmaster would read MAP at 8-9, so in comparison this seems low (which may mean low pressure=leak, right?). I have no idea if these units are the same though...

murphinator

iTrader: (2)

unmetered air getting in aka vacuum leak ?

try spraying some carb cleaner or similar flammable aerosol CAREFULLY around the intake/tb if you find a spot you can spray and the idle changes you found your leak

outkast6991

iTrader: (34)

Did you swap the valley cover bolts for button heads? Maybe it's cracked underneath and the carb cleaner isn't hitting it

sam95transam

Yeah, and I also ground the water pump. I don't know what else to try, so I guess I'll be pulling the intake back off and trying again.

Turbo306Fox

iTrader: (3)

Post up the fix when you find it

spy2520

iTrader: (3)

Has to be a leak or bad iac.