I havn't posted for a while but my dad is having the first major problem with our camaro. First off, it is a 1996 Z28, manual. Everytime he pushes the gas more then half way down it feels like your about to stall (jerking back and forth). It happens in every gear but only when the gas is pushed more then halfway. In high RPM's it runs fine. He thinks it may be a plugged cat conv. or possibly bad spark plugs. This car has 149,000 miles on it, everything is still original, spark plugs and all. Any ideas on what the problem is? Thanks

 

Try a tune-up to start, plugs and wires, and see what you have. 149k on the original plugs and wires is alot. If it's not the plugs & wires then you haven't lost anything since they probably should have been changed a while back. Start simple and see what happens .

Edit: Is the SES light coming on? If so, get the codes read and let us know what they are. If it isn't tune up related, a good guess would be a dead spot on the throttle position sensor since it acts up at 0.5 throttle.

 

It could be a fuel problem. This is the easiest thing to check. A plugged cat can be it also. The exhaust manifold could be so hot they glow in the dark. I took it to a mechanic and they checked it by drilling holes in the exhaust.

 

this happened pretty much over night. It had not been ran for about a day and a half and the temperature dropped outside a lot as well. Just some added factors.

 

I would check for glowing manifolds after you drive it. That's a cheap place to start, and could indicate a problem with the cats. If it runs fine in upper rpms, I'm not sure how likely it is that it would be the cats. When my cat failed, my car would barely pull itself along and wouldn't really rev at all.

 

Good call 69. The fuel pressure is easy to test. Get a fuel pressure gauge and connect it to the Schrader valve located here http://shbox.com/1/fp_reg.jpg. The fuel pressure should be about 40psi.

 

If it runs fine in the upper RPM range, and bad in the lower range, it is not the cats. Sounds more like either a fuel problem (weak fuel pump maybe?) or a bad coolant sensor.

Is the check engine light on? Do you have access to a fuel pressure guage?

Thomas.

 

the check engine light is not on

 

ill put money on it that its a fuel filter! that happened to my good friends car and hanged it and it was fixed. exacct same discription of what you said camarochic

 

but i would strongly suggest a full tune up

 

Its been said but the fuel filter should be changed if its old. This way if it is the problem you will know and not look at the fuel pump as the problem.