I've been driving a lot of l67 cars lately, trying to replace my Durango that somebody totaled for me. Does anybody know why some of these engines pull like a freight train, and others seem just plain weak? I have my suspicions, but don't want to mention them until the jury is in. I'm hoping it's as simple as I think it is. The engines have all been stock, and running smoothly. No apparent issues with them.
Thanks, Gas.

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Black 2000 GTP. Still stock, only had it 2 weeks or so. Straightening everything out first.

Mabe cheap oil changes, clogged fuel injectors, some how loosing compression.

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All sho no go...

Any neglected motor is going to lose some ponies from the stable over the years. Also, a butt dyno isn't the most accurate rating system

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

Matt pretty much nailed it. My 04 Monte always seemed like it pulled harder than my GTP but then again it had far less miles on it and I didn't know exactly how the GTP was maintained (I just knew it was in good shape but not excellent like my Monte).

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98 GTP (RIP 11-5-09); 73 Z28 Camaro (350, TKO 600);01 Monte Carlo SS (L36, L67/L32 hybrid in the future)
"Death smiles at us all; all a man can do is smile back"

Also, the PCMs are adaptive, so if you use 87 octane fuel, it will adjust timing for that versus allowing more timing when you consistently run premium fuel.

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One Big Ass Mistake America

I was thinking about the fuel issue myself. I'm not sure how these PCMs work. If I put some 91 or 93 in it, would it immediately restore the normal performance, or should i expect it to take a few tanks?

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Black 2000 GTP. Still stock, only had it 2 weeks or so. Straightening everything out first.

It would probably take a few tanks to do it unless you unplugged the battery long enough for the PCM to reset.

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98 GTP (RIP 11-5-09); 73 Z28 Camaro (350, TKO 600);01 Monte Carlo SS (L36, L67/L32 hybrid in the future)
"Death smiles at us all; all a man can do is smile back"

Battery reset FTW. Assuming the plugs and all seem to be good.

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Black 2000 GTP. Still stock, only had it 2 weeks or so. Straightening everything out first.

So would an N.A car get 10 more HP from running 89 octane as apposed to always running 87 octane? I tried the experiement for one tank once and only got better fuel econemy or atleast thats all I noticed.

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All sho no go...

I think it's just for boosted cars. I know if your car is intended for 87, running higher doesn't really help power (unless your getting KR for some reason)

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[url=http://www.xboxlc.com/profile/austin0150]

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yeah like i said slightly better fuel econemy but it didnt feel any different really.

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All sho no go...

I run premium in the 97 during summer because I can throw more timing at it in HPT and hyper mile the shit out of it. Whatchu know 'bout 37+ MPG?

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

For the original topic, it could be the factory freak thing. Some are just quicker. Therefore reason says that some will probably be slower too.

sent from my driod x, via my fingers through tapatalk

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2001 white gt coupe with enough crap to make it run mid 13's with 3 bad pistons
2002 40th GTP sedan mostly stock

Some engines got higher lift rockers, too. Some are 1.6 and some 1.66.

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One Big Ass Mistake America

cams too. the stock cam on the 01 had slightly more lift thent he official GM spec

also transmission if a trans is worn the car will feel slow case in point the GTX vs. the GTP the 99 GTP rips compared tot he GTX even though the GTX had headers and a CAI but thr trans was warn not noticeable untill you have a car witha fresh rebuilt to compare to like the GTP

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92 LeBaron Convert: Turbo 3L 97 Grand Prix GT 4dr "Frankenstein": L67 4t65 swap
97 Grand Marquis: Summer DD 99 Grand Prix GTP: Top Swap Beater

factory freaks

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i suspect the 99 is one of these. it is just nuts how quick it is compared to other GTPs and it has 196,000 miles

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92 LeBaron Convert: Turbo 3L 97 Grand Prix GT 4dr "Frankenstein": L67 4t65 swap
97 Grand Marquis: Summer DD 99 Grand Prix GTP: Top Swap Beater

Maintenance of ignition system components. Some cars have coils or ICM's on the way out which can also cause them to lose power. Bottom line is there are a lot of variables. It all depends on the motor's history.