Bad Acceleration??

[gsprague]

Hello All,

OK here goes nothing. I have a94 Z28 Camaro. I hardly drive it, maybe once or twice on the weekend, usually on the highway for an hour or two. I live in New England so it has been rather cold and the car just sits around most of the time. I have 40k miles on the car. Recently the car has been acting strange.

When the car is on and at a stop and i release the brake the car will begin to role, which is normal but the car will start to shake, kinda feels like an idle or transmission problem. Driving around town seems to be fine though.

Now when i get on the highway and i put the gas pedal down about halfway the engine will shake real bad and the car will not pickup at all. However, if i put the pedal to the floor the car will bypass the shaking and take off like there is no problem.

Not really sure the issue is. I think it might be my transmission or an accelerater bushing broke. Also the car does sit around all week in the cold weather. But before the shking would only happen for a short period of time till i got on the highway for a little while and the problem would go away. Now the problem is apparent and shakes at mid RPMs and doesn't pickup at all. Any advice would be great. Thanks!!!

[Christopherrr]

sounds like opti to me...that or bad wires or spark plug.

[gsprague]

Thanks, i'll have to look into that. Do you know how much a new opti spark distributor goes for, should i get a certian kind?

[PhantomZ28]

check your spark plug wired one might have gotten burned up touhing your exhaust manifold. (happened to me and felt the shakes like you) also if you got watter in the engine compartment rescentely a wre might nt be working rightand just need to gun it and blow out the moisture. but more than likely is the wires or plugs

[gsprague]

thanks, Yeah it only happens when i'm not pushing the gas and rolling from a break/stop. Or if i have the pedal have way down. If i have the pedal slightly down or to the floor it will run fine with no shakes. If it were a bad wire wodn't it happen all the time no matter where i had the gas pedal pushed to?

[PhantomZ28]

well what are your revs at? if your revs are low then the shakingwill happenbut thehigher the revs the less the shaking

[gsprague]

If i rev at about a just over 2000 RPM the shaking will shake my whole under engine and my car will not accelerate. If i gun it to about 5000 - 6000 rpms my car will take off with no shaking at all.

[gsprague]

Sorry it's been a long day at work. Here is the same post in English.

If i constantly rev just over 2000 RPM the shaking will shake my whole engine and my car will not accelerate. If i gun it to about 5000 - 6000 rpms my car will take off with no shaking at all.

[PhantomZ28]

LOL!! should relac and work on your car ^.^
but yeah thst does sound like one or 2 of your cylenders arntfiring correctely. my ar idrove for 3 days b4 a ses light came on. go and check that your plugs are all in tightly and that the wires arnt cut/burned in half but i dont think its the trans at all. hope ys get the problem solved.

[justen_shull]

I also burnt a plug wire on a header tube, and it wouldn't hardly pull up a hill. It just shook really. I had to down shift to go up hills till i fixed it. It would idle fine, although not smooth....306 comp w/1.6's. I think it is either a plug wire or opti.

[Craig 94 TA GT]

Well, if it is the opti, and you don't want to spend looooong, painful hours on it, a shop will normally charge 4 hours of labor for replacement.
Please do not go to the dealer to get an optispark unit... They will charge well over $700 where you can buy it at gmpartsdirect.com for half. The part number is 10457702.
I just had mine replaced 2 weeks ago - where I had no choice but to get one from the dealer. Long story short, over $1k in parts and labor. It still hurts...

I am assuming you're not seeing the SES light?

[gsprague]

Yeah, i'll just change them myself when the weather warms up a bit. But in the meantime i'll check to see if the any wires are shot. Do you guys recommend any certian type of plugs and wires? Thanks!!

[Christopherrr]

taylor wires 56mm and NGK tr55 plugs...I run Bosch plugs though on my TA...no reason, just couldn't wait for NGK plugs. I don't know how hard it is to change out LT1's...but my LS1 took almost 8 hours to switch...

[PhantomZ28]

8 hours on an ls1?? arnt the plugs easy to get to? their on top of the valve covers right? now i'm confuuzeled i'll check my friends ls1 later today

[brutalbird]

I've got a 94 lt1 and I've had the same thing happen a couple of times. I think it has been a fuel quality problem in my case. You are prone to condensation in the tank during colder climates, so a dollar can of dry gas may be the logical starting point. I would even suggest filling the tank at a known name gas station with the high test (of course), and dropping in a bottle of fuel system treatment. It's not a bad idea to use fuel system treatment a couple of times a year just to keep the fuel injectors clean, and make sure there is no water in the fuel. This is not only good maintainance practice, but hopefully might fix the problem. It worked for me, and being in Boston myself as well, I know you don't want to be working on that thing without a heated garage!
Good luck.