Hey guys i got a 1980 z28 with a 400 small block, and i just bought it 2 days ago it was running fine untill yesterday it wasnt idleing it just kept dieing when i let off the gas.. so i turned up the idel a little bit and i thought it was fixed... drove home and bout 5 hours later went to start it again... did the same thing, would NOT idle... I think it might be a timing problem or purhaps a dirty carb/fuel filter??

give me some input on what could possibly be the problem Thanks!

 

well if you just bought it. what i would do is..the following



id change all the plugs,cap, rotor, wires. take the carb off. and either rebuild it or clean it up depending on what you felt like at the time. change the oil and than see if the problem persist. also check the vacuum system. if you got a bad enough leak its gunna run like crap. let us know what happens!

 

How many miles are on the engine since the rebuild/replacement? To me it sounds li.ke the fuel system is failing and starving. Do you have a fuel filter on the line between the fuel pump and carb? What type of carb are you using, Carter/Edelbrock, Holley or other? If you have a fuel filter on the line just let the car sit a whi.le and then disconnect it and see if it's gunked up. If it's been sitting a whi.le the fuel in the tank could've gone bad. You can always buy gumout and try that also. If your fuel line seems to be working adequately then move on to the next step in troubleshooting which would either be carb or electrical (distributor). Atleast that's what I would check next. I don't think it's electrical li.ke the wires becau.se then you'd be missing on a certain cylinder(s) and for all of them to go out at one time li.ke that it would be difficult. If it were something li.ke that it would be coming from the distributor and then you'd need to troubleshoot that to see if it's firing correctly or at all.

 

im in the process of replacing the plugs/distributor and gonna clean the carb too..

to answer kyphur's question the motor has 45k miles on it since it was last rebuilt and yes i have a clear fuel filter but i think ill just replace it

 

ok i replaced all plugs, distributor and coil, i also cleaned the fuel filter and rebuilt/cleaned the carb, after i rebuilt the carb i bolted it back up and started the engine to make sure it worked... everything was fine with the carb but there was a loud POPING sound comeing from the distributor kind of like electrical shocking sound... so i turn the motor off and go inside to take a break come back out about 2 hours later and i go to start the engine again... the key turns but NOTHING happens.. (yes all electrical things in side the car work along with the headlights/break lights ect.) but the MOTOR wont turn it doesnt even click..

What is wrong?!?!!?

 

What kind of distributor are you running, and is it electronic or points/condensor?

 

If you replaced the distrubutor and it is running like crap and popping, you put the distributor in wrong. Or the timing is WAY off.
If you just replace the cap, you put the wires on wrong.

 

On one of my cars there was a stop on the bolts that held down the rotor under the cap down to the weights. One of the stops busted and the rotor would just flop around under the cap and would get louder and louder at high RPM's. It wasn't bad enough at idle up to mid RPM's in the driveway to even notice it but you could tell driving it and trying to bring it up to speed. Make sure your bolts didn't get stripped out on the rotor if you're hearing something like that is all I could suggest.

 

I FIGURED IT OUT, i had 2 wires mixed up.... i just started switching wires around untill there was no pop and on the 6th switch ... turned the car on and there was no popping and the motor was running clean ... OH what a great feeling it is to finaly fix this!

Now i just hope it well start better... gonna wait for the engine to get cold again

 

thats good dude. but for future reference. go check out this site http://www.boxwrench.net/ it gives you all the firing orders and torque specs for your engine. that way there is no guessing games. i did that once also. i must have adjusted everything 100 times and than i realized i got cyl. 1 and 3 messed up. man what an annoying thing, but im glad u figured it out.