stuttering or bucking?

[Jo4450]

I have a 93 Z28 with 93,000 miles on it and whenever the engine warms up to normal running temp the car always seems to stutter or buck when i accelerate at a moderate rate. The engine basically just dies when I give it like half throttle untill i let off the gas or when i give it all hell. Does anyone have any idea why the engine just dies like that? I would like to know if its happend to anyone else and what they did about it to fix it.

[mattinator1973]

My guess is either fuel pump or fuel filter. Also check plugs and wires. Wires might have crack in them causing arching.

[GeoZ28]

changed the fuel filter and the PCV valve.. then see if it still does it... and what grade gas are you using?

[Extinct]

Hey,
Go to V6 Performance Forum....Engine Tech....vibration.
Join the club of Camaros with this problem but can't figure our what in the hell it is.
See ya on the road,
Matt

[Jo4450]

I use 92 octane, but does this actually make much of a difference? What would happen if 87 octane is used?

[Lyle A]

It won't run as good as it should. High octane fuel is for high compression engines like LT1's

[L88427BigBlock]

Start with your fuel filiter, thats the cheapest. Befor your car gets to running temp does it run ok. It sounds like your plug wires, did you drive the car this winter.

[93PlumZ]

Bucking and stuttering sounds like the infamous condensation problem in the optispark distributor. Look for a slight voltage drop as the coli and ignition system is overloaded and crossfires.

[Dave_29]

Hey JO
I had the same problem with my 95 it ended up being the fule pump..But like Big Block said start with the filter first you never know you may get lucky......

[advizr]

I agree with most. Eliminate the easy first. As an owner who has replaced two opti's, it is great to be optimistic. However, I see too much on this board about fuel, EGR, PCV and Vacum as the cause of surging and bucking. Let's be logical, Is the problem intermitent, or regular. Does it happen at a certain RPM range or engine temp? Have you recently changed gasoline brands? Most hesitation problems that occur like clockwork within certain temps and RPM ranges are most certainly electrical. Plugs, wires, coil( don't forget the tiny little ICM mounted with the coil, then possibly OPTI, in that order!!!!

I am not omitting the possibility of a fuel related problem, but they are more irregular in occurance.

[Carlos01SS]

Don't forget the O2 sensors!!!

Isn't this exciting???

Stuttering? Bucking? Coughing? Farting? Loss of power? Is it happening between 1000-1500 rpm and/or 4500-5800 rpm or possibly throughout your rpm band sporadically?

First thing you do is to check the plugs & wires, make sure they are not fouled up or the wires are cracked/damaged/whatever!

THEN

Change the following, probably in this order, I THINK this is cheapest to most expensive

1.) Fuel filter.
2.) EGR valve.
3.) O2 sensors.
4.) Coil.
5.) Plugs &/or wires.
6.) Fuel Pump.
7.) OptiSpark...BUY NEW & also change the waterpump to a NEW ONE, might as well upgrade to a 160 stat...


Hopefully you won't have to reach #7.

Is that about right guys?

If you DO end up at #7, then at least you'll know that you will have new stuff to match the new Opti, so that's a nice thing.

Good luck!:D

[jester4736w]

Had the same prob wit my old Z... I'd say check your cat, u'd be suprized what a plugged cat can do.

[maquina001]

Did you ever get the problem fixed? I'm having similar issues; you can read about it here... http://www.z28.com/forum/showthread.php?t=103003

I don't stall, however. And also I get no codes. None.

[Carlos01SS]

Did you ever get the problem fixed? I'm having similar issues; you can read about it here... http://www.z28.com/forum/showthread.php?t=103003

I don't stall, however. And also I get no codes. None.


In a way I got it fixed, I ended up changing just about everything including all the sensors, only thing I didn't end up changing was the fuel injectors, but it still bucked and stuttered in high rpm...

So, I sold it. :yahoo:

FIXED!!! :lol:

Then I said fuggit and got me an LS1, no issues since...

[bakesz28]

I had a similar problem. After changing plugs, wires, O2's, Seafoam, TPS, fuel filter, PVC, it turned out to be the EGR valve. Plugged fullo****************, problem solved. whew....