3.4 Setup Issues

**Spartan GL** · 05-17-2010

So my Mod list engine wise is as follows

3.4
Speed Daddy headers
Cat Back Exhaust
2 Magnaflow mufflers
Wizaired Cold Air Induction
3800 Performance PCM (3.4 Mail order)
Autolite 104 Sparkplugs
Ported Supercharger, Blower and Throttle boddy
ZZP Supercharger Coupler
180* T-stat
MSD Coils
MSD Wires

Issues I'm getting is I'm getting crappy MPG (14MPG ish) and it doesnt seem to have the Boost it did before i put the new PCM & 3.4 on also the Boost gauge in the DIC only goes to half way

any ideas?

did the 1/8th in like 10.1

**TorqueAutoMotiv** · 05-17-2010

cat issue? o2 issue maybe isnt it a fresh build?

**Spartan GL** · 05-17-2010

i have new o2 Sensors, and I'm not getting any Codes from a scan

and i don't have a Cat converter I have headers and a catback with 2 magnaflows

**blueguy** · 05-17-2010

Vacuum leak...betting on it.

**OH4CompG** · 05-17-2010

Bluegtp91 took the words right outta my mouth

**TorqueAutoMotiv** · 05-17-2010

vac leaks where id check next

**Juanmiguel** · 05-17-2010

i bet on vac leak too.

**Spartan GL** · 05-17-2010

Originally Posted by bluegtp91

Vacuum leak...betting on it.

wouldn't that throw a code?

and i know the "T" fitting under the Supercharger, and the brake booster lines where else to check?

**SilvaMan61** · 05-17-2010

egr connectors lol

**Juanmiguel** · 05-17-2010

Originally Posted by Spartangl

wouldn't that throw a code?

and i know the "T" fitting under the Supercharger, and the brake booster lines where else to check?

My GTP had a couple of lines with tiny cracks and the MAP sensor vac line was completely clogged and was throwing no codes.

**TorqueAutoMotiv** · 05-17-2010

just follow all the vac lines and check the tb and so on

**gtpinsc** · 05-17-2010

is trans doing long shifts?

**SliceTheRice** · 05-17-2010

I've had vacuum leaks with no codes thrown as well.

Originally Posted by gtpinsc

is trans doing long shifts?

I know nothing about trannys. What does a long shift indicate?

**gtpinsc** · 05-17-2010

swicthing gears at a higher rpm than normal... under normal driving.. that damn T boot is a culprit for half full boost gauge and if leak is bad enough it will make trans shifts funny.

**minichopper6hp** · 05-17-2010

You need to delete your bbv solenoid, i see you have it hooked up in the pic you sent me. Also, 14mpg city is not uncommon when you have your foot on it...

**OrangeL67** · 05-17-2010

I had the same issue. It's a vacuum leak in one of them small lines over the blower.

**minichopper6hp** · 05-17-2010

I doubt it. He has replaced all those. Its the bbv solenoid stuck open.

**Bio248** · 05-17-2010

BUY A BOOST GAUGE AND STOP GUESSING AT YOUR CAR MAKING BOOST OR NOT!!

jesus christ...got all that money into your interior and you cant buy a $40 boost gauge and hook it up. that will tell you 100% if you have a vacuum leak or if you're not making 'full' boost.