Wide open throttle bog when accelerating issue.

I have been working on an issue with my 455 in my 66'. I just insured it a couple weeks back after a winter parked in the garage. It generally runs ok and cruises around just fine but once I do a wide open throttle acceleration it starts to bog once shifted into second. When it is colder it just seems to hesitate a little at or just after the 1-2 shift. Once hot it flat out bogs down until you back out of it. If you just lift for a second it will come back alive and you can carry on accelerating. I originally was thinking it was running out of fuel so I swapped out the fuel pump. It still acted the same. I then swapped in my spare quadrajet and I am still having similar issues. I was also having some issues that when I first hit it that the car would not accelerate as hard as it should then would jump to life like a switch accelerating hard like it should. I have also had some odd issues that I would shut it down for a bit when hot and it did not want to restart. After talking with one of my dad's buddies who was a mechanic his whole life, he said don't rule out ignition. I am an accomplished mechanic myself (even though I am an aircraft mechanic by training). I think he might be onto something. I am thinking I might need to swap in a new coil or consider issues with the MSD distributor or Crane HI-6 ignition box. The issues of acting up even more when warm really points to ignition. I am not sure if I will have any more time to diagnose before I head away for another shift away at work but would like to have a plan for more troubleshooting. I thought I would throw the question out there in case someone else has some ideas.
Greg

 

Ive got an unused Pertronix II I could send your way so you can test the ignition theory. Im not going to use it and it keeps you from buying something you may not need. if you don't have a stock distributor I've got one of those too.

 

That is very generous of you Bob. I have a MSD distributor in this engine so the Pertronix unit would not work in there. I do have an option to grab the HEI distributor I built up for my wife's 430. It was the only extra distributor I had and her 430 engine came without one. I don't like the big cap HEI on the old cars just because they don't look right and are bulky. They can work pretty good though. That unit would be the quickest way to rule the ignition out. That Blaster 2 coil was used when I installed it 25 years ago so I am suspecting it might be the issue. I am going to try and swap it out first. I would be interested in that stock distributor and Pertronix though as the engine I am putting together to swap into my 66' does not have a distributor and I wanted to run it in on the engine stand before installing into the car. As I said I gave up my only spare distributor to my wife's build.
Greg

 

Just let me know. I have a distributor, the pertronix, and a Moroso advance recurve kit all of which im not using

 

Maybe we can work it out in the deal of the other stuff I want to buy from you. I would like to take it off your hands for sure. Like I said, I would like to have another distributor available.
Greg.

 

I agree Larry that was why I went chasing after the fuel pump right off the bat. I have not ruled out fuel starvation yet. I picked up a couple pieces that I need to plumb up a fuel pressure gauge. I am going to grab a gauge and a remote line kit tomorrow so I can check pressure while driving. I am going to grab a new coil from the same place as well. That MSD blaster coil is 30+ years old. It will not hurt to have a spare if nothing else or I can use it for my 55' Chevy build. I would think that pump could easily supply the fuel needed. I am wondering if the tank sock is plugged up a bit or it is sucking air somewhere along the line. Unfortunately I will not be able to do a whole lot more looking at it for a couple weeks as I am packing up to do a shift away working. Hopefully I can sort it out quickly when I get home again. When I get it sorted I will be sure to post the answer. I hate open threads without solving issues.
Greg

 

Plugged sock on the pickup tube?

 

It is certainly a possibility. The tank has always looked clean and I have never even found a spec of dirt in the fuel filters but anything is possible. I have a 3/8" fuel pickup and 3/8" line front to back. Aside from a plugged up sock it should feed a 375hp motor no problem. When I was swapping out the pump I blew back up the line to the tank so the fuel line would not keep siphoning fuel down my arm while I was working there. It seemed to blow back easy. It should of cleaned the sock up if it was dirty too.
Greg

 

I went through this with a buick 350. It simply wouldn't make any power when the secondaries opened up. It ran fine otherwise. I tore my hair out swapping carbs, fuel pumps and ignition parts. I eventually found that half the cam lobes were flat..

 

I can
t picture it pulling as hard as it does in 1st if the cam was flat. When it doesn't bog down it has decent power.

 

I had a wide open throttle issue when I was air flow limited by the air cleaner. Just a thought.

 

Same with me on my 350... I flipped the air cleaner lid without putting a taller filter on it and it ended up giving me less air flow. It was always bogging at WOT.... put the lid back to normal and realized the bog disappeared. Taller filter fixed that issue.

 

I can't picture it being an airflow issue. I have run the same air cleaner for years. It is a 14" open element K&N with a Corvette L88 drop base. It will flow plenty.
Greg.

 

try locking out the secondaries and see if it pulls all the way to 4500-5000. Assuming you're running a q-jet, there a secondary lockout lever you can zip tie in place. if it runs better on the primaries, you know where to screw with next..

 

Check the rubber sections of fuel line, the inner layer of rubber may be collapsing when the fuel pump really starts sucking, but fine normally.
I had that issue on my GS years ago, floor it and shed nearly stall, back off gas she’d recover.

 

I am confident that the small amount of fuel line at the engine side is all good as it is new and it is NHRA approved twistlock style with AN fittings. Now at the tank end the rubber is 23 years old. It is on my list of things to check when I get back home.
I am sure it is not either of the quadrajet carbs. They have both been rebuilt in the last couple years and have worked well. Two carbs having the same issue is unlikely.
Greg

 

If it is a factory 3/8 fuel line it will have a rubber section about midway and also a rubber section from the line to tank. On another note if the fuel sock in the tank was weak when you forced air through it you could have separated the sock and now when trying to pull fuel through it, it is collapsing.

 

Yep, just under the drivers door along the frame rail