Big block cutting out when you stomp it

[HotRodPC]

I've got a 70 Olds 455 running an OE 2bbl, probably 500cfm and it's rated over 300hp, IIRC It's 330hp, and if it were 4bbl, it would be 390 rated. Of course, it gets a tad bigger cam and a .5 bigger compression if it were 4bbl. But, small cfm is always OK. I know of a guy at the races back in the day, he ran a gutted 2bbl didn't lope a bit and put a spankin on many cars that were loping and 1 even running a tunnel ram and dual quads.

I still think it's something in the timing. That 16 degrees and not running a 4 degrees shouldn't have anything to do with the acc pump in my mind.

 

[Myfirstbigblock]

It's idling at about 800 in park and 550-600 in gear it had a m
750 holly on it when I bought it I took it off because it was backfiring out the carb and I couldn't get it tuned so instead of rebuilding it I replaced it with a brand new Edlebrock 650 thunder ASV off road while changing it I found the vacuum port in the back of the 1" spacer was open so I took the the spacer off it helped with the backfiring but it didn't go away then I replaced the entire ignition that got rid of the backfiring but now it cuts out when I stomp it from an idle I've got it running good as long as I don't try too do a burn out from a stop

 

[Myfirstbigblock]

Sorry wrong thread

 

[Myfirstbigblock]

Sorry wrong thread

Never mind right thread

 

[Myfirstbigblock]

This truck is is a 4X4 I'm not trying to run the quarter mile or 100 MPH down the freeway I'm looking at 5,000 RPM max in the mud I know 16* BTDC is too much but it won't run lower then that and it's an Edlebrock not a Q-jet I'm lazy and Edlebrocks are easier

 

[Myfirstbigblock]

Did you adjust the accellerator pump?

No I don't know how

 

[Jims86]

Wont run on lower than 16btdc....
When you set the timing, did you unplug and block the vac line to the distributor, and did you set it in park, or in gear?

 

[Jims86]

No I don't know how

Curt...I think you may want to splain this one...its been a while since I messed with an Eddy.

 

[HotRodPC]

It's idling at about 800 in park and 550-600 in gear it had a m
750 holly on it when I bought it I took it off because it was backfiring out the carb and I couldn't get it tuned so instead of rebuilding it I replaced it with a brand new Edlebrock 650 thunder ASV off road while changing it I found the vacuum port in the back of the 1" spacer was open so I took the the spacer off it helped with the backfiring but it didn't go away then I replaced the entire ignition that got rid of the backfiring but now it cuts out when I stomp it from an idle I've got it running good as long as I don't try too do a burn out from a stop

OK, now I get it. But no backfiring now? I see why they're saying to check the accelerator pump now. I still think it has something to do with timing. And if it still backfiring even just a little, that also can be timing, and can also be a valve. I'd do a vac test on it and see what the guage is doing. There is a diagnostic Vac Test chart here on the forum. Fairly certain it's a Sticky too. In the Engine and Perfomance section.

 

[Myfirstbigblock]

sorry i havnt been on in a while i got deployed to afghanistan but the truck is still in savannah at a budys house he says its running good he put a fuel presure regulator on it and adjusted the carb a bit but he drives a cobalt so i dont know what he considers good

 

[HotRodPC]

Well Hey, Thanks for stopping in for an update. Thanks for your service buddy. Be careful and make it back home safe, sound and in one piece.