Bad misfire needed solved yesterday

[truckman]

I posted this in the 2.8 section but not enough traffic fast enough.

Long story short i blew a fist size hole in the motor of my car and was forced to finish my truck in record time. start new job tomorrow and can't barrow the girls car any more

Got it all up and running and ran in to this problem, (copied post from other thread)

Little history on the motor its a remain 2.8 in a 85 ranger w/ 27,000ish on it has a comp cams stage 2 cam, shorty headers, offy intake and holley 390cfm, dura sparked w/ the GM 4 pin unit.

Now for the problem i put a new dist. from napa in after i trans plated the motor in to my new truck. got a new ign. modual, new cap rotor and plugs and wires.

Go to fire it up runs ok at idle set base timing at 10deg. go to take it for a drive it runs ok at low rpm like just a little throttle. Put it under any load it will kick and buck for a few secounds then cough and take off but misses sounds like its missing on 1 maybe 2 cylinders let it go back to idle it runs fine and free revs fine a lil pop out the carb every now and again.

this made me think timing but i've had it was far as 10 deg retarded to 30? but could not fix the broblem

I've played with the timing for 2 days and had now luck I've never had this problem before with this.

I'm looking for suggestions to fix the miss fire.

Thanks,
Zack

 

[feellnfroggy]

Dont retard the timing try advancing a little, also, the stuttering and buckin-- is it poss the carb is jetted wrong and its running too rich?

 

[truckman]

i mistyped i've set it as far as 10deg ret. to 30 deg advace

Carb ran fine when it was in the other truck i haven't changed any thing 2 it.

 

[BlackBII]

I'd run it under load and then check the plugs. Check if it is running lean or rich maybe. Perhaps the carb needs a cleaning or the accellerator pump aint pumping

 

[martin]

sounds to me like it's running lean when the manifold vacuum drops. Perhaps the power valve is not working. If the carb has been dry for a while it's a distinct possibility.