To summarize everything quickly, I bought a used 1994 Camaro Z28 about a month or so ago. So far it sounds amazing and seems to be running well, but unfortunately I'm nothing close to a knowledgeable person with motors or cars in general -- I'm more of a computer tech guy. There are only two things I know that are wrong with the car; one being that the catalytic converter is coming apart (at least that's what I've been told a clanking sound is), and the other being that oil pressure gauge is broken (but that doesn't really matter because I have an aftermarket one).

Anyway, a friend of mine wanted to race me, and being young and stupid, I decided to take up his offer in a drag race on the highway... in the rain. Luckily nothing bad happened of this dangerous event, especially considering how inexperienced I am, but I discovered that my car is not performing the way it should be. Various sources and videos show my same car doing 0-60 in roughly 5.7-6.2 seconds, but I found myself getting up to the same speed in something more like 10 seconds. My friend was driving an Acura Legend V6, and he was right next to me for the entire thing until he stopped keeping up at around 70mph. Remember, I'm no car person; I'm just looking to be pointed in a general direction of where this might be happening, and if and how it can be fixed (not that I should really have the power :P).

Here's a video of two runs because I thought it might serve a purpose:
1994 Camaro Z28 - YouTube

The first run (which is actually the second run of the night) is with a small step on the gas at first and then to the floor in a more or less failed attempt to keep the tires from spinning. The second run in the video is from stop to flooring it, spinning the tires for roughly 3 seconds.

Anyway, any help is greatly appreciated.

 

the bad catalytic converter is causing your problem ......
the engine needs to let out the hot exhaust out if not it will kill your power

(1) fix the catalytic converter
(2) stop filming your self while racing ..........

is your camaro bone stock ?

 

It is having some kind of problem around 4000rpm. The engine seems to be stalling around that RPM. It might be a cat problem. The acceleration from a cat problem, that my brother's '99 3.8 V6 Camaro had, did not hesitate at all. It simply had no power and smoothly accelerated....albeit very slowly. Also, it would not rev past 4000rpm. Something for sure is amiss with that LT1(be it engine or transmission). My brother's 3.8 was an automatic(4L60E) as well.

I don't know much about the automatic transmissions, but for sure get those two problems you know of fixed quickly before you run it hard.

Can you give us more info on any more symptoms?

What year is the Legend? Some late model V6 cars are no joke in the HP department compared to a stock LT1.

Now, I have a CC503, long tube headers, 1/6 roller rockers, and a 6 speed manual. Here is how mine is in the acceleration department for comparison. I had just fixed an oil pressure dipping problem. It starts spinning the tires at 3000rpm in 1st, but notice that the acceleration is very smooth with no hesitations.

Oil Pressure issue solved

 

I think it sounded like it was stalling at 4000rpm because that's when the tires stopped spinning, but I'm not sure. Another symptom I can think of is my poor mileage. Yes, driving like this causes bad mileage but I filled it and drove it normally to find out what I'm really getting. Most of my driving is a mixture of light city and long highways (I live out in the country), so I'd expect something like 18mpg, yet I'm finding myself with only 14mpg.

A different possible symptom I forgot to mention is that instead of losing power when the car shifts, it actually jerks forward pretty hard.

As for whether the car is stock or not, I'm not quite sure. I've been told that the exhaust is aftermarket and that some of the pipes--don't know what they're called x(--are also not stock. Just in case there are some new things you can spot, here's a picture of what's under the hood:



Might not be a very good picture, but it's dark out and this is all I have until tomorrow.

 

When you bought the car, did you change all the fluids, check the condition of the plugs and wires, scan if for codes? Any idea how old the O2 sensors are?

Maybe it's just the crappy sound on my laptop, but it seems to bog and misfire at 4,000rpm as mentioned above. If it was a plugged cat, I'm not sure it would even recover and make it up to the 5,800rpm redline.

The poor fuel mileage indicates its running rich. That can be caused by misfires, or exhaust leaks before the O2 sensors.

For starters, pull a couple spark plugs and check the condition. If you don't know how to read them, post some good photos. At night, in the dark, lightly mist the plug wires with water, and run the engine, looking for signs of arcing around the Opti, coil and wires. Best diagnostic tool would be a data log done with software like TTS DataMaster or FreeScan (which isn't "free" any more). I can also give you a link to some new free scanning software developed by a member here that can read both the PCM and the EBCM.

The only mod obvious from the engine photo is a K&N cold air intake, and an aluminum elbow (Vortech?) from the MAF sensor to the throttle body.

 

Well, I took it down to Jiffy Lube and got (almost) all of my fluids taken care of. There was one thing they said they couldn't do because of the placement of parts in the engine and that they didn't want to damage anything by removing it to get where they needed to be, and I believe that was flushing the coolant or something (I really don't know what I'm talking about...). One of the things I believe they did was replace the fuel filter, and that did seem to help a little bit with my acceleration problem -- I haven't floored it or anything -- but it's still lacking. So, could you give me some more details on that software and how to use it? Is there some sort of specific computer I need?

I'm also aware that this kind of power isn't really something I need, but if a car isn't capable of its stock potential then I wouldn't consider it healthy, and healthiness is what makes things last. ...And what's a Camaro without being an impressive performer anyway? :P

 

Based on my experience with collapsed cats on my '94, you would never get to 60 mph. I'm not saying that couldn't be your problem, and I'm sure the effects vary depending upon the nature of the collapse, but my car wouldn't do much more than idle when the cats fell apart. It certainly wouldn't accelerate, at all.

 

Jiffy Lube???? Next time, try replacing the fluids yourself. It would be a good first step toward learning more about your car, with the added bonus of reduced cost, and certainty as to the specifications and quality of the fluids used. Have a friend who is truly knowledgeable about engines, transmission, etc. watch you and guide you. Learn how to do it, and move on up the ladder.

 

Sorry for the late reply -- I've been extremely busy with school since the last day is just a few days away.

Anyway, yes, Jiffy Lube. I will admit that I didn't know that it was something that's frowned upon, but in my own defense I'll also have to say that the only reason I went there was because it was a gift from my father, and he wanted all of my fluids and everything else to be replaced and checked, and he made sure that they gave me the best thing they had. As far as doing it myself in the future goes... I'll try, but I don't really have any connections or friends that actually know anything about cars or mechanics; anybody that's available to me only claim to know a lot about cars, and I know that because they're all young teenagers and made stupid mistakes on cars that even I wouldn't do... I don't exactly trust them. I could grab some tutorials online or something and just be careful with what I'm doing, but that could be just as good as having an inexperienced friend help me, maybe even worse.

As far as my problems go, it all seems to be orbiting around the cat (bad mileage, bad acceleration, ect). My friend's dad heard it when I drove over to his house and he said to just pull it off completely. Then I called my stepdad and he said not to take it off, but to just clear out all of the broken and loose parts inside of it to get rid of the rattling (he might have said to scrape it all out completely, I don't really remember) and he's thinking of having somebody he knows come out here and do that with me. I live outside of the smog area, so I don't believe I need to worry about tests or law issues or anything else like that. But does this sound like it could solve my acceleration problem?

 

I didn't mean to come across as trashing Jiffy Lube. I drive a company car, and they have us take them to Jiffy Lube. On the other hand, I think everyone who comes to a site like this has a strong interest in treating their car the best they can, and from my experience in dealing with car dealers and auto shops for more than 50 years, I simply don't trust most of them.

If I do it myself, I know exactly what parts or fluids were used, and that they were installed correctly. I've seen too many dealers and shops screw up the simplest tasks.

When my Formula was new, I took it into the original dealer for a couple minor warranty type items, and to have the rear axle lube replaced (required at first 7,500 miles only). When I got the car back, they had charged me for an oil change and filter. I asked them why, since I didn't authorize that work. They said it was a mistake on the bill, and took the charges off. When I got home, I looked under the car. The oil filter I had recently changed had definitely been removed (it was scratched and dented) and the same damaged filter put back on the engine. I guess when they pulled the filter off, and saw that I had written the date and mileage of the change on the filter, they realized they made a mistake, and tried to cover it up by putting the filter back on. It was also obvious the oil had been changed. Since I was using only Mobil 1 synthetic, I was pretty sure they had not used synthetic to replace it.

Went back to the dealer, asked for the owner, and stood and watched while they replaced my filter with the same oversize AC Delco unit I used, and filled the engine with Mobil 1. The owner turned out to be an OK guy - he told me how he managed to pick up one of the six 25th Anniversary T/A convertibles with the manual trans, and had it stored in a warehouse out in the desert.

Point is, don't trust anyone with your car, unless you absolutely have to. There is a huge amount of pleasure in spending the weekend working on your car, and starting it up and listening to it run. I started working on cars before I could drive them, then worked in a gas station/shop part time all the way from high school, through college and then even 5 years after graduating. It was great to have a place where I could put the car on a lift, and have access to just about any sort of tools and equipment I needed.

 

If the cat is bad, your only options, or the only options of which I'm aware, are to remove it or replace it. If it has collapsed, it will definitely impact performance. Personally, I'm surprised it's driveable. Do the manifolds glow after the car has run for awhile and do you have metallic shavings coming out of the the exhaust?

 

I can see where you're coming from with your stories in dealers. Even though I don't work on cars myself, I do work on computers, and I can relate with what you're saying. My mother had trouble with her computer a few times, so she took it to a store to get it fixed. What they did to it was not the right thing for solving her issues (completely formatting the hard drive and doing nothing else, not even hardware diagnostics), and out of anger she asked for a new computer entirely. She got one, unfortunately for a pretty price, but a few years later when I started to pick up on how these systems work, I came to the conclusion that the computer they put together for her was only a touch above trash. I've seen computer shops and companies (Alienware and Apple especially) that invest too much in one part and not enough in another, making the system have less actual performance and be more expensive, and then on top of all that, they sell it for far more than it's actually worth. Because of this, I build all of my own systems and I even build all of my friends' computers too. If there's a problem with any of them, 99% of the time I fix it myself.

As for my car...
I'm not sure about the glowing, but the sound is very loud (a friend said he heard it over my engine when I was coming down the road, and my exhaust is LOUD) and I have seen a lot of small metal shards coming out of the pipes. The 'check engine' light actually came on at some point but then turned off again. And it's strange; the performance sometimes has a nice kick when I press down on the gas a bit hard, and other times it feels weak. Same goes for the noise -- sometimes it clanks, sometimes it doesn't. I feel like it just needs to get knocked loose, and I really hope this is what's causing my issues along with my bad mileage. Speaking of which, what kind of mileage should I expect with no cat?

 

Welp, I got my car fixed, so there's nothing to worry about anymore. :P Thanks for all the advice though, everyone.

 

It would be a good thing to let us know what was wrong in case someone in the future has similar problems and finds this thread while searching(plus im sure people are curious). Glad its fixed and be wise about racing on the street as the car can get away from you and if your not experienced in a slide or when the back end tips out it could be fatal(plus any bystanders and cars next to you)


Posted from Camaroz28.com App for Android

 

I apologize. When I said my car was fixed, I was talking in terms of the catalytic converter. I recently found out that my car still has very poor acceleration, and I have started a new thread regarding that.