3.0 running terrible at part throttlew

[tomritt]

Ok, so I am just finished up my 1700 hr project and I can't get the thing to run properly. Its a 74 with a 78 3.0 on factory cis. The car used to run fine 2 years ago. Its is pretty much the same as before with the exception on an msd 6al, and a bosch 044 pump. Driving the car, on light load it hesitates and backfires like mad, and then at about 4k rpm, it feels like it runs out of fuel. At wide open throttle the car runs great until it hits that wall around 4k rpm. I have verified timing is correct, I have take the cis and intake off the car and replaced the boots, injectors seals, intake gaskets, and verified there are no vaccum leaks anywhere.

I do still need to verifiy the timing is correct, can't find my timing light, but have tried rotating it slightly to see if the problem got better or worse and there seemed to be no difference. I do still need to check my fuel pressures, but thought id see if anybody else had any advice or ides.

Thanks in advance for any suggestions!

[stlrj]

Running the original shielded ignition wires?

[70SC]

Check for H2o in your tank /system. Clean & flush. CIS Hates water or debris Check the injector spray patterns. Good luck . I just had my fuel distributer rebuilt, Cleaned & flushed my fuel tank/system ,New fuel lines ETC..... Now it finally runs GREAT . Lots of low end power,all the wayfrom 1500 to 7,000 R's. Nice cold start , First click of the key every time

[70SC]

[tomritt]

Hmm that's a good point, I will check for debris. The car has clewitt wires now, and a new fuel filter. I had the tank out cleaned and Recoated so theres was no water in the system but I wouldn't be surprised if there was debris in the fuel head

[Flat6pac]

Sounds like youre running out of advance on the distributor when you hit a wall at 4000. Pull the distributor and remove the pod and see if there is about 35 degrees of rotation available. If not let me know.
Bruce