My LT1 feels slow...

[LT1drifter]

I just bought a 94 TA A4, has a new NAPA motor in it, with around 3K miles on it. I have been reading and see a lot of people with stock setups having traction issues, even when hitting second. Mine won't even sping the tires stomping on it at a stop sign, or chirp in second. Does this sound normal? Anything I should maybe check? At the moment my 2.0 turbo 240sx making 200whp feels faster, and I hope it shouldn't.

Thanks for the help.

[myersfw]

Welcome to the site, and Howdy from Ft, Worth! :LS1LT1flag:

I guess I will start with the usual questions - is the SES (Service Engine Soon) light on? Does it run better cold or warm? Any hesitating or surging, pinging or knocking? Is it hard to start? I apologize if this seems stupid, seeing as you have a new motor. "New motor" doesn't always mean new sensors. These old girls tend to need things like O2 sensors, distributor cap and rotor, coil, spark plug wires. Other things we do include cold air intakes, large bore throttle bodies, coolant bypasses for the throttle bodies, head and cam packages,and myriad of other performance oriented modifications.
My point is that the more you can tell us, the more we can help you.
You're in the right place. My car had been stored for years, and she needed more than a little help to get the kinks out, and six months later, is a completely different animal.
Post back up and let us know - glad to have you :coffee:

[LT1drifter]

Car has 180K, I'd say all of the sensors do to, along with the acessories, and water pump( getting an electric unit soon). No check engine lights, it seems to pull harder when it's cooler. Fires right up, no pinging or knocking, no hesitation. I am still new to the LT1, I hope that when they swapped the motors they did plugs and all, I will have more time this week to check out more into the motor.

[kevstoy]

maybe some dummy used thicker gaskets during the rebuild? Thicker gaskets= less compression. Less compression= less power. That's the first thing I could think of since there's no SES light on. I mean, hey, you never know...

[aajj1987]

i would have the motor checked for the specs. advance auto parts sold me a motor that was supposed to be lt1 and my mechanic said with the cam and heads they put on it. its a wonder they were 200 horses. i take it he was being sarcastic. but i wound up returning it and buying a lt1 out of a 96 z28 wrecked and the car felt like i could eat up that old motor. i would just check it out. i mean a lot of remanufactured motors may not be true lt1's just something to look into.

[LS1ZZ28]

with a generic rebuilt motor there is no telling but what gear go you have in the rear end

[scoob8000]

What size rims/tires do you have?

[heavymetalpornstarZ28]

f bodies r heavier than the 240, my guess is you need a proper tune up, have ur compression checked also ur gear might be a 2.73 rear, the LT1 is a cast iron grunt monster u wont b disappointed despite the future headaches she'll give ya

[ProjektNitemare]

u hope they did plugs wires etc?...should be on the build or install estimate sheet and if they arent then better go get em. check your coil too, and also your cat may be a little plugged after so many miles, the MAF may need cleaning, your air filter etc...all things to look into. its usually a pile up of the simple stuff that causes things like you describe, not one huge thing.

[Zupercharged28]

you check youre cats? clogged cats always slow up a car MAJOR and if they didnt put in new exhaust with 180k on the old cats? i dont wana think about it!!

[RatedZ]

i would have the motor checked for the specs. advance auto parts sold me a motor that was supposed to be lt1 and my mechanic said with the cam and heads they put on it. its a wonder they were 200 horses. i take it he was being sarcastic. but i wound up returning it and buying a lt1 out of a 96 z28 wrecked and the car felt like i could eat up that old motor. i would just check it out. i mean a lot of remanufactured motors may not be true lt1's just something to look into.

I used to work for AAP. Don't EVER buy anything from them, especially motors. Of course, you unfortunately found that out the hard way.

My dad had purchased an ATK L98 for his 1989 GTA and it was a total slug. It turns out that there was a vacuum leak somewhere. Have you checked for vacuum leaks? Once the leak in my dad's car was fixed, it felt like a totally different animal, albeit, it was still a slow animal. :)

[95Trans am]

I cant spin them off the line most of the time because its automatic. I hope thats the reason.

[aajj1987]

it depends what type of exhaust you have. i have straight pipes with glass packs. and from a dead stop mashed i cant spin the tires. i can usually catch a nasty second and roll em over at least once when i do. but the trans you have does the shifter go to low 1 or can it only go low 2. i heard something about optional gears. dont know if that would make a big difference but it may.

[myersfw]

Final drive gearing makes a huge difference! Being one of the 2.73 crowd, I can attest to a reluctance to roast them off the line - it will, but only if you really push it, aka power braking.
There's a guy who lives about half a mile from me with a '95 Formy, all loaded up with an M6 and 3.42s - he just walks away from me every time. I catch up a little when he's busy shifting. (Winding out second on 2.73s is a blast!) Since I've added a few goodies, it's not as bad, but I won't be beating him until I get into a set of 3.42s myself.

[LS1ZZ28]

sounds like 2.73's alright and it is true most of the time if your shifter does not have 1st it is a 2.73 rear gear

[RatedZ]

I cant spin them off the line most of the time because its automatic. I hope thats the reason.

Nope, that's not the reason. I have an A4 and 3.23 gears, and prior to my engine rebuild, I could put the tires up in smoke like there was no tomorrow.

[Garrett TX LT1]

Alright

LT1 rebuilds are EXPENSIVE because GM doesn't make a CRATE LT1 motor anymore so if you didn't pay more than you thought you should something may be fishy

2:73's suck if the car is an automatic your trans is probably old and that may explain why you don't get a 2nd gear scratch along with the 2.73s

You should still spin tires on the street with a 245ish tire without much problem

Drive a buddies with similar mods, if his has 100k more miles and is faster...you have a problem :)

(open an LT1 up...they really like to breath)

[aajj1987]

check your exhaust for leaks. i know a small exhaust leak on a lt1 will kiss your tourqe goodbye. but all in all worst comes to worst sell the motor for what you can and buy an ls1.

[novebmer452]

i got the same problem, i have 95 t/a, i can spin the tires from a dead stop i have ot hold the brakes down... Another problem is hard starting, it cranks for like 4secs then starts. I have a feeling its the fuel pump, but does a pump rly kill that much power? Is there an easier way beside dropping the whole tank?

[stfuad]

i got the same problem, i have 95 t/a, i can spin the tires from a dead stop i have ot hold the brakes down... Another problem is hard starting, it cranks for like 4secs then starts. I have a feeling its the fuel pump, but does a pump rly kill that much power? Is there an easier way beside dropping the whole tank?

How do you know it's the fuel pump or are you guessing? Test the pressure before and after the filter and at the fuel rail. Hard starting doesn't always mean fuel isn't getting to the engine.

[novebmer452]

How do you know it's the fuel pump or are you guessing? Test the pressure before and after the filter and at the fuel rail. Hard starting doesn't always mean fuel isn't getting to the engine.


If its not the pump what else could it be?

[96redlt1ta]

If its not the pump what else could it be?

Fuel pressure regulator