I dont think I would do that, I think I would pick up an aftermarket 2bbl replacement in a larger CFM.

I will be sure to do that. It was liveable during the summer as 90% of the time it left the light with no hesitation only rarely did it. Now with this cold weather it feels like its doing it 90% of the time and running fine only 10%.

 

I have seen the EGR gaskets burn out causing a vacuum leak. If you want to experiment and take it out of the picture, get some thin aluminum and make a solid block-off gasket for the egr, and bolt it between the egr and the mounting to block it off temporarily.

Since you have done so much work to the carb, what timing are you running? Have you played with it any?

I have also had a problem like this, and it was my fault. There are two passagways in the intake that connect one exhaust passage in the one cylinder head, over under the carb to the other cylinder head. Exhaust runs through this passagway making a hot spot right under the carb to keep the fuel atomized. I listened to too many hot rod stories, and blocked mine off to keep the carb cool. That was a bad decesion. It made the engine really cold natured with lots of hesitation and bogging. I undid the block-off plates and everything went back to normal.

 

Honestly I cant remember the timing I think the emission decal said 18* BTDC which is what I set it at. It also said + or - 2* which I tried 2* more advanced which should in theory improve low end power. But right now I am running it at what the emisson decal said for the timing.

I also bumped the idle speed up a little I had it idling at 500 RPM in gear now its idling at something like 650 RPM in gear.

I honestly have been thinking of either cutting out a block off plate at work and just block it off, I already dont have a converter thats been hacked off, and I planned on removing the air pump down the road but that wont be till I get replacement heads or I pull the motor to tear it down and find out what else the engine shop cheaped out on.

 

18 BTDC is way to high for most emissions engines. It might have been 8 BTDC.

 

It could be, My Mercury though I know for a fact its 15* BTDC and thats an emission engine, with the primative map sensor that this car came with plugged in that uses manifold vacuum to advance timing more than the vacuum advance on the dist, it is actually 22* BTDC total timing at idle without the vacuum advance attached at the dist. Runs great and gets great fuel economy.

But I might be thinking about that 351W for the 18 but I will check the tag on the truck to see what it says.

 

I know my 351w complains like crazy on startup if it's over 12* BTDC.

 

Really? Might be cause I have a yellow strain relief DSII on my 351W where as my 302 in my truck has just the blue strain relief DSII

 

It'll drag the starter down pretty dang good past 12* BTDC. I have a blue grommet box. I run manifold vacuum and 10* BTDC for starting. Runs real good that way.

 

I try to run as much advance as possible but I try not to go too far past what is indicated unless the starter doesnt drag when starting the engine after its hot.

 

Mine is specced for 10* factory. It did run a little better at 14* BTDC all throughout the power band but the starter really hated it. So I decided to put it to factory and then run manifold vacuum to make it run smoother and better at idle.

 

My 302 is manifold vacuum my 351W is ported vacuum. But I screwed up on my 351W cause while I was disconnecting the vacuum advance the primative map sensor economy booster is plugged to manifold vacuum so I never was setting true base timing. While I thought I was at 15* BTDC base timing I was really at only 6* when I disconnected the economy booster. I set it to 17* BTDC as it said 15 + or - 2* and with the economy booster plugged in it went over 20* BTDC. Not sure what total is with the vacuum advance on the dist is.

But that engine runs damn good and pulls hard. I just need to resolve my truck, I will be checking the EGR this weekend if it doesnt wash out like the weather people are saying.

 

You do not figure official "total" advance with the vacuum advance in the equation. In other words, when you read on the web and in books that total advance should be in the 30ish range on most engines, they are not figuring in the vacuum advance. With the vacuum advance, the total advance can be in the 50's. The engine will take that much advance with no load on it.

 

I know mine is in the 50's at cruise speeds with the vacuum advance in.

 

I checked the EGR valve today, poured water ontop of the valve and slowly the water seeped past the valve into the EGR valve.

Went to two stores none of them had a EGR valve on hand, and they said they dont sell block off plates cause its highly illegal to touch the emission systems.

Looked online for a block off plates but they are way too thick so I will either be purchasing a new EGR valve or just make one out of aluminum to bolt in as a solid shim between the EGR valve and the mount.

I also looked at the emission decal it does say 8 degrees timing and thats what its on as I set it to the sticker.

 

A plate made from a pop can will work for a while - long enough to figure out if that is the problem.