Hello, I recently purchased a broke down 94 z28. I had the car towed to the house and put a new starter on it and it fired up. Well it took a little while to actually start but after that it would start somewhat easy. I took the car on the road and it seems to run ok under acceleration. My problem with it is if you are just cruising on the highway at say 50mph around 2000 rpms it will start hesitating but if you get on it, it seems to clear it out and it will run ok for a while. It also does this when the car is just sitting there at idle but if you "blow it out" it will run just fine for say a minute or two. If you let it idle it will load up and eventually die and it hard to restart. My question is why is this? There is no service engine light on while all this is going on.
I changed the plugs from Bosch (worn out) to NGK TR55. The car had MSD 8.5 wires so I just cleaned them up and examined them and didnt find any flaws so I reused them.

Any suggestions would be greatly appreciated

Thanks
Chad

 

Monitoring it with a scan tool would be helpful.

 

Fuel filter maybe? Its a cheap thing to buy and real easy to install. I agree wit a scan tool also.

 

My guess would be leaking injectors. Did you have them cleaned before you restarted the engine?

 

I have replaced the fuel filter this did not help.

Injuneer, how do you clean the injectors? I have never done this.

Not sure if I wrote this in the first post. but there is a strong fuel odor at idle when it starts to act up.

Thanks for the help.
Chad

 

I would have the injectors done by a professional. There are ways of doing it yourself, but a good shop can pressurize the system with a solvent and get it done right. Check them first though, you can pull the fuel rail off with the line attached and turn the key on. If you are dripping fuel from anywhere, you have a leak.

 

Its probably cheaper to buy a new set of injectors than clean them. I had a set cleaned and flow matched by TPIS many years ago and it was $30/injector.

 

There is a company that does it for 12$ an injector.

 

The name of the company would be kinda helpful.

 

Did they flow match?

 

I have used this guy and have gotten great service http://www.witchhunter.com/

 

The good thing about TPIS was that if they could not get one of the injectors clean or to flow within a reasonable match, they would substitute another injector from their stock. I got back 7 originals and 1 replacement.