Ok, I have a couple things here, so i will try and make this as non-confusing as i can. I'll admit, this is long, but im trying to give as much detail as i can.

Up front, I have a 1994 LT1 Camaro A4 2.73 with 70,8XX on the clock. We had a tune up done at roughly 64-65k miles. With the tune up came new plugs, plug wires, coil, freeze plugs and *fuel injectors I think*. (I wasnt the owner until 68k miles). The transmission was also rebuilt at 68,5XX miles. Im not sure what plugs were used, but the plug wires that are being used currently are (as reads on plug) "Belden Premium 7mm Cable-SAE Class F-JE". The only mods are a SLP CAI. No exhaust work, chip, nothing. I use Valvoline Oil and Wix filters, I just installed a new Wix fuel filter 2 weeks ago.

Now, this car was driven by an older couple all its life, my parents. The car was never run hard except for the occational fun on the highway or a stoplight to stoplight race. The car has never been driven in snow. When i purchased the car, i talked trash to my friends and such and decided to take the car to the track for the first time in its life to prove my point.

Heres my first track time:

60'=2.501
1/4=16.171
MPH=84.19

I was so pissed and decided to run again.

60'=2.437
1/4=15.874
MPH=87.53

Now, i didnt want to break the car or anything (i was shaking the whole time when i dragged) so i went home for the day. I figured being the first time on the track, i would automatically run slow. This was back on the 18th of July. It was about 90* out so i figured to car was hot too.

Now last Friday night, i decided to take the car back out to drag race my friend. (He has an '84 cutlass with a 400 chevy, turbo 350). I had raced him on the street and beat him before but we had installed a 3.73 gear and he wanted another piece. Here's our times. *(I'm car 78)*



I barely beat him but i was still mad that i didnt get under 16 seconds in a Z28. I ran again, this time against a Turbo Regal. (Again, I'm car 78)



Now, on this race, i floored it, no preload or stall, and at about 3-5k rpms, the car started bogging bad. It almost felt like someone was grabbing the car and shaking it back and forth. I let off the gas and it shifted into 2nd and i got back into it.



Now, my question is why is my car running like sh*t? Is it the opti or something else electrical? I have no lights on in my dash except for the occational low coolent light which is a bad sensor. Also, when im driving on the highway to college, i sometimes feel a slight chugging. I never thought anything of it but sometimes its really noticable. Misfire maybe? On another note, if im driving wide open throttle, the car stays in 2nd for a really long time. It doesnt shift till its at about 6k rpms. And when it does shift into 3rd, it makes a funny "Whoosh" sound as if someone was letting all the air out of a ballon at once. Im thinking about taking it to a local shop around here that works on mostly sports cars (F-bodies, Vettes, Mustangs, Supras, 350Z's, etc). I'd like to know what you guys all think and what the problem might be. That way, i can let the shop know and hopefully steer them toward the problem.

If i left any details you need out, let me know and i'll try and respond as soon as i can. Any imput would be appreciated.

Thanks guys,
Matt.

 

The car is going to run worse at 90 degrees than 70, so that counts for some of it. The chugging is probably missing or the opti. I know that I'm being really open about it, but I don't want to steer you wrong. My SES light never comes on either, but the bulb is burnt out, so you might have some codes or there could be something wrong with the bulb or wires and you wouldn't know. Some parts stores like Advance Auto will scan it for free, just ask. You'll probably have to hassle them a lot cause they're lazy, but some places will do it for free.

Did you check to see if the wires were arching anywhere? You can check while you have a friend rev it up cause you said it doesn't miss till up top.

Don't know what to tell you about the transmission, I had mine rebuilt so it doesn't act like normal ones.

 

Well, im in an automotive class so I can get the car scanned thursday. I dont think its the tranny, it runs smooth when the car isnt acting up and when it shifts gears, it puts you in your seat.

I know temp is a big difference, but it seems like it's running worse since July. I havent checked any wires, i had an extra one laying around so thats how i know what it was. I'm not that mechanical on these cars yet, (Only 18) and i dont want to risk screwing up anything by pulling plugs and wires and stuff. But i'll definatly get into getting it scanned Thursday.

 

Sounds like a possible bad catalytic converter, fuel issue, spark.... Get it scanned. See if you have any knock retard. Look at the cat when the car is running for a while at night. See if it is starting to glow red.

 

Don't be so eager to jump on the blame the opti bandwagon. It could be as simple as plugs or wires, a fuel filter, ect.

 

your 60 is killing you, that's part of the problem.

 

New plugs and wires were put on 5k miles ago, and a new fuel filter put on 2 weeks ago. I hope its none of those yet (plugs and wires)

 

It's really easy to burn a wire, or cut it on a pulley running it through. It's not really uncommon at all.

 

His MPH should be way over 87! You should be pulling AT LEAST 97-98mph.

 

I ran 14.9@95 with out the nitrous with a 2.4 60ft up in colorado @ 6000+ feet above sea level. Oh and I have 143,000 miles on the original opti. Your car should be running mid 14's

 

I know. Thats why im so befuddled here. If one of the wires is cut, can i see it better by jacking up the car and putting it on a lift? How would i keep it from getting cut again?

 

There is something DEFINITELY wrong with that Z28. Your 1/8 times should be low 9's, high 8's. Right now, that thing is running like a 3.8 V6.

I think the exhaust(cat converter) would be a good starting point to check on. My bro's 3.8 V6 cat clogged up and that thing was terrible on power. After changing the cat, it felt like it picked up 70-80hp. No joke.

As far as the opti....is it breaking up, stumbling, or have a high RPM miss? If not, I'm not sure I'd pin this problem on it.

 

I'm not denying that he's got other issues, I simply stated that the 60 was one problem. LT1 Cars in this area run 9.0's all day long in stock trim, so he's way off the mark.

 

Yeah, I told my mom the car was running like a V6 and she just said "well, its not made for the track you know". It doesnt seem to lose power uptop at all, it feels really strong. How much do you think it would cost getting the cat looked at/changed? Im in college and i was going to get a winter car but i wanna get this one running right first. I have about $500 to my name

I was searching around, and heard a couple times that if your cruising, and feel a "light chugg", its called cam serge. What is that?

Thanks for all the help so far guys!

 

First, do the ultimate basic stuff. Check the plug wires to be sure they are all connected to the plugs, and underneath the front of the car at the opti. If I were a betting girl I would say one of them came unplugged and the car is running on 7 cylinders.

Aside from that, get the codes pulled and go from there. When you are new to cars you might have trouble "feeling" something like a misfire or high RPM miss, so see if you can get someone who knows cars to ride in it.