Well, my Camaro has been running fine for the last year or so since I got it back up and running, and it's been a good daily driver. However, I've discovered a problem, and I'm not exactly sure how to describe it. On the way to school today the car was fine going up the hills here in Anaheim and down them in the 40 mph zone. As soon as I turn onto E Santiago Canyon Rd and I accelerate past 40 (because it's a 50 mph zone) it starts to seem like the engine or something is slipping. Under enough acceleration it just seems like it slips. It's not a constant loss of power either, it's kind of sporadic (but not extremely noticeable). I don't know if it's the transmission, the rear end, or the engine. But honestly, when I got home (it still did it on the way home as well) I revved the engine and it just sounded awful. It was sputtering a little and backfiring a little too. For those who don't remember me from earlier, this car did sit for about 5 years more or less. I'm not sure if that has anything to do with it. The transmission fluid is fine, the oil is fine. I'm really confused. I tried to debunk it as bumps on the road, but it wasn't the same thing, there was a subtle difference. I mean, I've driven this road at least 100 times in the last year and a half. Not to mention I drove on it last week (Tuesday and Thursday classes), and I can tell that this isn't bumps in the road. My car is fine from starting from stops and going up hills. I just can't figure out why it does it at certain speeds. Anyone have any ideas?

 

One potential reason is the throttle position sensor. It may be worn in the particular spot relating to where you notice the sputtering. You'd have to measure the output voltage to make sure it changes smoothly and doesn't spike up or down anywhere. You can do it on the car by sticking a pin the correct wire or take it off and bench test it. Either way you need to know which wire to test and it's too long since I did it to remember. Do you have a manual with circuit diagrams.

 

Does it throw a code? Check engine light?

 

Hmmmmm, maybe. Yeah I do have a repair manual for the car that has circuit diagrams in the back. Guess I'll try that.

Nope. The only thing that ever shows up is my Infl Rest light, but that comes and goes with the wind it seems.

 

If you do have a slipping trans that could also throw off the computer as it may get a false speed reading.

 

Well I drove to school and back today and I've definitely noticed something. It's no longer just happening at speed, its beginning to happen when I start off as well. It's weird, it's like whenever I accelerate from a low RPM, the car feels like it's "bobbing" or something, but when the car downshifts to a lower gear to get up a hill it stops. I mean, the car is now starting to react the same way it did when we didn't have the vacuum line attached, (or whatever that pipe/tube is on the back of the intake that connects to the vacuum. When we were first getting it going my grandpa had decided to change the spark plugs and the spark plug wires, and had accidentally forgot to reattach that pipe/tube after he has taken it off. So every time I started from a stop there was a delay of some sort. We finally fixed that and it stopped doing that. The car is almost like that right now, except at low RPM's in any gear. By the way, I checked to see if it was still attached, and it is). So I'm confused now, I don't think it's the throttle position sensor, but then what do I know?

I don't think I've seen the Speedometer off anymore than it usually is (I've noticed that its about 5 mph slow, So 45 mph on the speedo means I'm going 50). And I'm able to keep up with people on the street and it still displays the same speed it usually does, though it's hard to say, I don't know for certain how fast anyone else is going. On a side note, it made a weird smell for like a second when I was trying to accelerate from a higher gear. Is it bad to run the car in overdrive when going over mountains and hills? Because I always do. That said, I did put it in drive and it still did the same thing pretty much.

 

Do you mean the little vac line that goes from the back of the manifold to a small black box attached to the firewall? That's the MAP sensor and is vital to proper engine function. It's another thing that could be bad so it can be bench tested as well. You need a vac pump, a digital volt meter and a 5 volt dc power supply (a usb port will do). Like the tps test you need to measure the output voltage compared to vacuum and make sure it operates correctly. BTW have you checked for vacuum leaks? A must before doing the other stuff.

 

Yeah, that thing, lol. I guess I'll try that. I was at the races yesterday in Bakersfield and one of the crew members on our team told me that it might be the fuel injectors. And that kind of made sense, the car was sitting for 5 years. It's been fine the past year or so and I was using that Lucas Oil fuel injector cleaner stuff. It's been a couple months since I've used it though. How do you check for vacuum leaks?

 

Start by visually checking all the hoses carefully and replace any that are cracked or split or badly deteriorated. The rubber gets brittle. Listen for hissing. You can spray starter fluid or some other volatile spray around hose connections and if hear an increase in revs it means the vapor was sucked in through the leak.

 

Ok, this is the hose I'm talking about



That was the thing that got unplugged, but was plugged back in. This isn't a vacuum line is it? Because it just goes to a green connector and I assume it provides power of some sort. So I assume that by vacuum lines you mean these other rubber pipes around the back of the engine right? The ones that go over the line I circled?

 

Thought I'd just dig my old thread back up instead of making a new one.

Right, so the problem I had before with the irregular idle, and weird vibrations under acceleration at low RPM's are still there. BUT, I have a new problem, this morning on the way to school (I have to drive up this pretty big hill to get there) the power cut out half way up it, and did it about 3 times, the engine didn't stall, but it was like I let off the gas, when I didn't. It later did it again after I was starting from a stop light. So obviously, this is a pretty big problem for me. It only seems to happen under enough acceleration really, because it didn't do it at all on the way home, but I drove extremely careful. There is also a small clicking sound that I can hear on the passenger side of the engine, and the engine is also louder on that side (but that's probably because that's where the exhaust goes out and whatnot).

I should point out that I did pass smog not even a month or 2 ago, even while I had the irregular idle problem. So I don't think that it's a vacuum leak (unless it's small enough to effect my car but not my emissions).

As for the vibrations under acceleration at low RPM's, would it be possible that my tranny mount is going bad? Because I can almost hear some clunking when it gets really bad and feels like I'm going over bumps in the road, which I know I'm not, it happens way to consistently when I'm at a low RPM. On a side note: Is it bad if the rear end creaks and such when I accelerate? No matter how fast or slow it is? Because it's kind of freaking me out that my transmission is just going to fall out of my car here eventually.

Also, I have no warning lights of any kind (apart from Infl Rest, but that's on all the time, which I guess means my airbag doesn't work right? Goes with the theme of my car really....). Oh yeah, my tachometer stopped working the other day as well, does that mean anything?

One last thing that really doesn't need to be answered unless you want to, why has the switch on the center console for my rear hatch stopped working? And how come my hatch will only close completely (grab on to the hatch latch) if I slam it down (only found that out when I got extremely frustrated and slammed it like 3 times because I had school tomorrow and it was already 9pm and had a 4 hour drive home ahead of me).

And that's about all I have to report on my car, I obviously don't expect anyone to answer everything, my main concern is the power cutting out, that I would much appreciate having answered.

 

Never mind, turns out the coil plug or whatever was loose and was causing the power to cut out. And the rough idle was caused by the spark from the middle passenger side cylinder jumping to the head or whatever. So everything is fixed. Also, the apparent creaking I've been hearing was my stupid tail pipes coming up and vibrating against the bumper.