A friend referred me to this site, so maybe someone can help. Let me start by telling about my car. its a 1995 z28 with a 6 spd and 112k miles. Most of the engine has been rebuilt within the last few months, including waterpump, valve springs, roller rockers, lifters, push rods, K&N intake, comp cam, timing chain, gaskets and a few other minor parts. The car has been running great, until yesterday. All of the sudden i developed a nasty hesitation. It almost feels like it has bad gas or is running out of gas. Something i have figured out. When its cold it runs like a champ. As soon as it warms up the hesitation comes. It also seems to get much worse while accelerating into or out of a curve or turn. And also seems to get worse when going over a bridge. I changed the water pump 2 weeks ago and the car has been running great since. I have checked under the car and on the pullies and dont see any kind of coolant leakage. The only thing i know of that needs replacing is the intake elbow. It has a slice in it right by the trottle body, but thats nothing new. The car has ran fine with it like that. I dont know a whole lot about cars so hopefully someone can point me in the right direction. Any help would be great guys.

 

I don't think it a gas issue, when I got a load of bad gas the car ran like crap all the time.

Might be the optispark (or the igniton coil), the other thing I would look at is if you are gettin the correct fuel pressure.

 

my opti was doing that under load, kinda like when you go up hill on a bridge. could have been that the opti got leaked on enough to do it some damage.

 

Would any of those ideas coincide<sp> with the car being warm? If it was bad gas or opti spark wouldnt it always do it? even when cold?

 

ttt

 

an opti starting to go bad but now quite bad woudl do it under load, same with bad gas, if your concerned with bad gas drop in some octane booster.

 

You say your intake elbow has a cut in it. You should get it replaced. If you see something wrong, fix it. Maybe it is not causing your problems, but trying to troubleshoot when you have things that are broken does not make any sense.

It also seems you ignored the sticky at the top of the forum about abusing TTT. I'm guessing the moderators are going to get a little more strict about it, since they left the post in plain site for all to see.