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Technical Areas => Questions and Answers => 4th generation cars (1993 to 2002) => Topic started by: Michael on July 23, 2007, 08:51:06 PM

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Title: Hesitation On A '94 Firebird
Post by: Michael on July 23, 2007, 08:51:06 PM
I purchased a 1994 Firebird with a 5.7L LT1 and it is having a problem with running properly.

I changed air filter and fuel filters.

Here is the take on it.

When first started it runs perfectly fine. Purrs like a kitten. Then after it warms up, it starts loping. It chugs and pukes during acceleration, unless you floor it or actually give it gas like you mean it.

I took it on the highway to see if I could get a Check Engine Light... I did.

I floored it and ran her to around 85 - 90 and the Check Engine Light Came on and then it ran perfectly again. Didnt have to floor it to actually cruise.

After maybe a minute or two... the light would go off and the engine would return to the gotta floor it to go state of mind again.

She sucks gas like theres no tomorrow also. You can litterally watch the fuel gauge drop. It's sad. lol, especially with the cost of gas in Dallas.

A friend of mine has a scanner and we pulled three codes from it... A/C Compressor, O2 Sensor & O2 Sensor Right Bank running lean.

I knew about the A/C... its a switch thats bad... it works after you hit the dash fonzy style.

I bought a new O2 sensor and spent a few hours trying to replace it and gave up and called a shop to do it for me.

I havent had it done yet... supposed to take her in tomorrow.

My question is...

Can I rule out vacuum lines and fuel injectors if the check engine light comes on and car runs perfectly?

Also, would a fuel pump do this? I couldn't see how it would.

The car has all the power in the world. It will burn tires from a dead stop with no braking then throw second gear scratches all day long with no hessitation whatsoever. It will even throw a third gear scratch.

I ask this because the shop I took it to was hesitant to change the sensor... after seeing the engine lope in the compartment.

I just dont see how an injector or fuel pump would be bad if you can floor it and it'll run fine then when the light comes on it runes perfect. Makes no sense.

Any help or suggestions would be kindly appreciated.  :-\ ??? :-\
Title: Re: Hesitation On A '94 Firebird
Post by: maggotpez on July 24, 2007, 11:40:41 AM
You have 4 02 sensors 2 b4 cat 2 after try to replace all.  Also look up the LT4 knock module might not solve all your problems but it does help at higher RPM's good part is they are like $40.  Back to the 02 sensors they sit pretty open on your exhaust just unplug them unscrew they from pipe they add new.  Ill see if I can get you a picture of them soon.  Hope this helps.
Title: Re: Hesitation On A '94 Firebird
Post by: TunerTools on August 18, 2007, 05:20:33 PM
Michael, did you get the O2 sensors replaced yet?   and did that clear up the problem?
Title: Re: Hesitation On A '94 Firebird
Post by: 00furybird on February 23, 2008, 10:41:43 PM
i reacently had a similair problem with my 00 and it turned out to be the catalitic converter dunno if this helps or anything but i had to change my 02 sensors as well
Title: Re: Hesitation On A '94 Firebird
Post by: cdc_customs on June 23, 2008, 09:42:00 PM
I had the sameproblem on my 95. Turned out to be the egr valve. I replaced it and the car runs great now.
hope this helps.

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