On my way home today I was driving my normal speed (55) then when i hit the gas my z28 felt like it had just died;rpms went to 1000 then a back fire in the carb and everything kicked in and took off (this was all with in 2 or 5secs). I went to a stop sign everything was fine normal idle i hit the gas and it took off like normal. got to the next stop sign, hit the gas and then it did the dieing back fire thing again. anyone know what would cause this.

83 Z28, 305, stock cam (i think),edel brock preformer carb, preformer eps intake, mallory vaccum dist.,10 degrees btc, 1,000 rpm idle in dirve, 700r4 trans, stock rear end, stock heads, stock exhust manifolds.

 

Check the plug wires? I had a plug wire that wanted to "almost" pop off a plug every so often - it would stay attached, just not fully "engaged" enough to always make the spark - sometimes it did, sometimes it didn't, and when it didn't, you could really tell - like you described. I squeezed the end a tad with the pliers, popped it back on the plug, and all is well.

 

Done a fuel filter recently?

 

I put a new filter on about 2 weeks ago it looks fine.. I will check the plug wires again after work. an the way here today it seems to have gotten worse. now if i use a 1/4 throttle it does the back fire thing.

 

It is fuel related.

You probably won't find anything about the plug wires that will cause this.

How much fuel is in the fuel bowl if you drive the car, make it do it, and while it's doing it, shut the motor off and take it out of gear and coast to the side of the road without allowing the fuel system to fill the carb back up by idling? The object of this exercise being, to see if the carb fuel bowl is being drained dry while driving, and the fuel system can't keep it full.

 

Might be the accelerator pump. With air cleaner removed and eng off, look down the carb from above with a good light (open the choke plate if it's closed), and move the throttle open rapidly. You should see a healthy squirt of fuel into the primary throttle bores. If you don't see a good healthy squirt, the pump is bad, or the float bowl is going dry as prev mentioned.

 

If it runs good once it gets over the rough running part and hits the high RPMs i very highly doubt its a fuel pump/filter. More like stated above, the accelerator pump. The engine goes lean, dies out to a point where its got enough fuel to catch up then it spools up.

Or something to that effect...

 

I'll take a look at that...Yesterday i advanced the timing to 12 degrees and after that it ran like a bat outta hell. but then this morning it started back up again... I will take a look at the accelator pump before i leave work today.. to all

 

ok the accelerator pump is working fine... But if the torque converter is going out could it stall the engine just long enough to cause the back fire thing?... only reason i ask is cause at one point on my way home when i hit the gas the rpms went up with out any speed increase.