My 81', 720 series wont stop bogging!! Help?

[Slammed720]

So i have been dealing with the issue of my 81' Datsun pickup wont stop bogging when i give it throttle too fast or when its not completely warmed up, and even then so. So i had to turn my timing to 20!!! not really enjoying listing to the high idle to my engine =( but cant drive it any other way! If i turn down the timing it bogs so much i cant drive it! Any suggestions??? It has the stock Z22 in it, with a Weber carb, Pacesetter Header, and Flowmaster exhaust!! I can Rev it up in neutral all day without bogging, but as soon as it hits the pavement, the throttle just bogs it out????

[datzenmike]

Did it run properly when you installed this Weber? Or has it run properly in the past? If not it may be jetted for a smaller displacement motor.

 

If the problem started recently you probably have a blocked jet in the primary causing it to be extremely lean. This could be dirt or water sucked from the tank. Is your fuel filter good? I've had the element come loose inside and let all the crap past.

 

Some bogging is normal specially when cold. The Weber is much larger than the stock Hitachi and this is what a larger carb does. Excessive bogging at low speed in, say second, while stepping on the gas while going around a corner in town could be a bad accelerator pump. Engine and air filter off, look down the carb and work the throttle You should see a strong sudden squirt of fuel into the bore. If not the accelerator pump needs rebuilding. What happens is the engine is going very slow and when the carb is opened there is in effect a huge vacuum leak. It takes vacuum in the venturi to suck fuel in but because the motor is going so slow this fails and the engine only sucks air. The accelerator pump dumps extra raw gas into the intake to help the motor transition from this low speed lean mixture and help it get going on it's own.

[albyneau]

So i have been dealing with the issue of my 81' Datsun pickup wont stop bogging when i give it throttle too fast or when its not completely warmed up, and even then so. So i had to turn my timing to 20!!! not really enjoying listing to the high idle to my engine =( but cant drive it any other way! If i turn down the timing it bogs so much i cant drive it! Any suggestions??? It has the stock Z22 in it, with a Weber carb, Pacesetter Header, and Flowmaster exhaust!! I can Rev it up in neutral all day without bogging, but as soon as it hits the pavement, the throttle just bogs it out????

 

 

Need more info as Mike suggested~

 

Another thought might be a weak/faulty ignition system. Putting a weak spark under load will literally "blow out the candles"....

 

Scott

[elmerfudpucker]

some pics, and more info please.

[datzenmike]

Two things to check, won't cost a cent

 

Valve lash, even if you check it cold there should be some wiggle on the rockers if there is any clearance. Be sure cam lobes are down and the valve closed when checking. Tight intakes will act like a vacuum leak and have poor manifold vacuum.

 

Pull the intake and exhaust plug wires off, one at a time if you want. Stick an old plug in the end and ground to the exhaust manifold. Have someone crank thew motor and look for a spark. If one of them isn't firing replace the first fuse on the left in the fuse box. Replace don't trust looks. This motor is designed to run with both plugs. If one side isn't working it will act like it needs more timing. Stock timing is 3-5 degrees, 20 is just wrong.