So as you all probably know, my mileage has "always" sucked on my car. First it was my thermostat being stuck open the first winter, then it was a bad O2 sensor, but now I guess I finally figured out the root of my bad mileage: My "replaced" LIM gaskets. Somehow, when haro and I put it all back together, something didn't get assembled right and there must've been a vacuum leak through the LIM's or something. This explains why my car would rev up and down while cold during the summer, why my mileage sucked, etc.

My DIC currently says 29.6 MPG over 73 miles. I seriously cannot believe it was that all along...

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Bye Bye:

RIP sandrock

Nice, glad to see it's finally fixed...

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Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

Maybe I should do mine!!!! Should get better over the next little while, now have a long commute to work, 98% highway,

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1999 DCM SLE- COTM Jan 2012
Planned mods... FWI, Exhaust and tips,Tinted all around

She's now gone:(
http://pontiacbonnevilleclub.com/forum/viewtopic.php?f=8&t=31352&p=312104#p312104

Just make sure you get everything sealed up and torqued down right. I think that was my problem...

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Bye Bye:

RIP sandrock

How'd you figure out to check the LIM bolts?

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2012 Chevrolet Cruze Eco - Current car

1999 Buick LeSabre Custom - Former car

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

viewtopic.php?f=9&t=30207

I re-did pretty much everything, and it solved the problem, lol.

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Bye Bye:

RIP sandrock

Glad to hear you tracked it down Ed. I know you have been tracking this one for awhile!

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Eric

2005 SLE, Greystone Metallic, 152K.

A few mods..

Who would have thought power mods would help regain some MPG's in that great of an effect?

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Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

I haven't noticed much symptom wise that'd suggest a vaccum leak, It idles at 1500 dead cold (-26 today...) and then drops as it warms up. Occasional little stutter whether hot or cold... But have been hoping to see better than 20~ MPG average. will have to see if it increases with more highway driving.

Regardless, 29 is impressive!

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1999 DCM SLE- COTM Jan 2012
Planned mods... FWI, Exhaust and tips,Tinted all around

She's now gone:(
http://pontiacbonnevilleclub.com/forum/viewtopic.php?f=8&t=31352&p=312104#p312104

Great, so now you can actually brag that you get better mileage than I do

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Jerry /// Past: 95 SSEi (June 2010 COTM) -- 04 GXP (July 2011 COTM)
91 Honda Civic Wagon DX 2WD (fuelly) -- 208,000km -- 92hp -- Autocross Warrior
09 Lexus LS460 AWD -- 94,000km -- Daily Driver
09 White Hot G8 GT -- 155,000km (fuelly) -- LS3 Cam -- GM LS3 CNC Ported Heads -- Kooks 1 3/4" Long Tube Headers -- Solo Catback Midsection -- Hooker Maxflow Mufflers -- Pat G Tune -- Rotofab Intake -- Tein S-Tech Springs -- GXP FE3 Dampers -- BMR Subframe Cradle Inserts -- BMR Subframe Connectors -- Forgestar F14 Gold 18x9 +40 -- Michelin Pilot Super Sport 245/45/18 -- Maverick Man Carbon Fiber Spoiler

What was the mileage you were getting before?

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Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

20 MPG on the spot, no matter how I drove.

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Bye Bye:

RIP sandrock

Gotcha. Nice to see you got it mostly dialed in, and that it works!

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2012 Chevrolet Cruze Eco - Current car

1999 Buick LeSabre Custom - Former car

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

Were your fuel trims out of whack?

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*Gone, but not forgotten* - Black 2000 SSEi, HIR Headlights, Angel Eyes fogs, 3rd brake light overlay, hi-flo cat, 180 degree thermostat, HS 1.9 rockers, LSx yellow springs, Intense FWI, PCM, shift kit, push rods, and 3.4 Pulley. ZZP Power Log.

No, which is the weird part. I never did check my FT's at idle...

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Bye Bye:

RIP sandrock