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I can see two equally solid steams of fuel when manually activating the throttle with the engine running or not running. Streams strengthen as throttle is applied when running...all that appears to be normal.
I just crawled up into the engine bay with a can of carb cleaner...this time i used the little straw...and when I shot the back of the carb the engine died completely. Looks like a leak between the manifold and spacer or the spacer and carb. I can't imagine this leak hasn't been there since I've owned it so I'm not sure it is related to my issue. I'm guessing it very well could be. Looks like I'll be pulling the carb.
I guess that explains why backing the mixture screws out more than 3 turns has no added effect...it can't get rich enough. Funny though, it smells like a mosquito sprayer...but I'm pretty sure that's an exhaust leak (next sub-project)...I digress...
So, if I'm following the symptoms correctly, could it be that starting from a stop or accelerating under any type of load is pulling more air through the apparent leak than the engine can provide in fuel to balance the mixture? Would that explain why flooring it yields better results? Due to the extra fuel being dumped in to help compensate?
Just trying to wrap my head around carbs 101...
Thanks for the help with this. Hopefully a positive update by the end of the weekend.
Yes, you have it nailed. When you take your time accelerating the vacuum never goes below something like 8" of vacuum. But, when you floor it the vacuum will drop to something less than 5" of vacuum. However, the power valve opens at something like 6.5" of vacuum and will enrichen the mix significantly at that point.
So, when you take it easy you are using the fuel coming out of the idle + cruise metering systems, and that's not enough with your vacuum leak. But, when you floor it the power valve opens and gives enough fuel to the mix to let the engine run well.
Disconnected the choke spring as suggested. No change. Still dies on acceleration.
Thanks for humoring me. I'm officially stumped.
The fuel pump volume test results you posted are a little low, but i don't really think such an issue would cause the symptoms you have. Still, it is below specs so I'd be okay gambling your $30 on a new fuel pump to see if that is any help.
Unfortunately (or fortunately, depending on your point of view), we have reached the end of my troubleshooting knowledge in this field. What I know about carburetors could easily fit in a thimble, with room left over to hold everything I understand about women.
Edit: While I was typing, I see you posted about finding a major vacuum leak. Ignore my comments about the fuel pump. My last paragraph is still valid, though.
Removed the carb today to fix the leak issue. Didn't see anything obvious but there was pooled oil in the back recesses of the intake, near that area. I guess it's either the hose from the PVC or the gasket(s). I'm replacing all of it anyway.
I decided to remove the intake and valve covers, since I'm making the effort, to do a little spring cleaning. A coat of corporate blue never hurt anyone. Had to remove the distributor to allow clearance to lift the intake off of the front left stud. I noticed that the cap is marked with a '1' for the #1 cylinder location...verified that matches what the manual I have suggests. However, the plug at this location went to my #8 plug. Am I missing something? Does the DSII conversion change something I'm unaware of? My #1 plug wire was 180* across the distributor from the marked '1' location......
If someone pulled the dist. out they installed it 180* off and why the #1 tower went to #8 plug. Some find it easier to do this than pull the dist and turn it 180*
Could be they is where the oil pump drive lined up.
Dave ----
I decided to remove the intake and valve covers, since I'm making the effort, to do a little spring cleaning
I'd suggest not getting too deep until you resolve the original acceleration issue. Even though you found an apparent vacuum leak, it is still there. Now you're running into problems with the plug wire routing and you've got all sorts of other things disconnected, too.
It would be SUPER easy to accidentally induce a new problem, such as cracking a vacuum line during reassembly. Talk about a troubleshooting nightmare. This thread might change from "idles fine, but poor acceleration" to "backfires when trying to start and caused my teenage daughter to run off with an oxygenated fuel lobbyist".
I'd suggest not getting too deep until you resolve the original acceleration issue. Even though you found an apparent vacuum leak, it is still there. Now you're running into problems with the plug wire routing and you've got all sorts of other things disconnected, too.
It would be SUPER easy to accidentally induce a new problem, such as cracking a vacuum line during reassembly. Talk about a troubleshooting nightmare. This thread might change from "idles fine, but poor acceleration" to "backfires when trying to start and caused my teenage daughter to run off with an oxygenated fuel lobbyist".
Just looking out for ya.
I agree with you. I'm guilty of all of the above. Once I start tearing things apart it turns into "well, I might as well do this too" and snowballs from there. I'm trying to throttle myself...pun intended. I did find a shredded vac plug on the tree at the back of the intake though...so that's two leaks.
Is there any sense in ripping the carb apart? I've cleaned/checked the bowl and float area earlier. I suspect there may be some blockage elsewhere but I don't want to get too carried away (as you mentioned). I didn't see anything abnormal in the bowl so is it likely I have junk in the fuel passages?
KR does have a good point on doing too many things at ones and really causing other issues.
For now leave the 180* dist as it does run the way it is and look into the first things you posted about.
After you fix all vac leaks and re-adjust the carb, check timing take it for a ride and see how it goes.
Now this "no acceleration" is it slow to accelerate and low on power? Has a bog or heasatation on acceleration?
Just got thinking of something and your dist swap. I did say check timing above and that is at idle what is the mechanical advance & total advance on it? You will need a dial back timing light to check them. This will effect acceleration. Dave ----
KR does have a good point on doing too many things at ones and really causing other issues.
For now leave the 180* dist as it does run the way it is and look into the first things you posted about.
After you fix all vac leaks and re-adjust the carb, check timing take it for a ride and see how it goes.
Now this "no acceleration" is it slow to accelerate and low on power? Has a bog or heasatation on acceleration?
Just got thinking of something and your dist swap. I did say check timing above and that is at idle what is the mechanical advance & total advance on it? You will need a dial back timing light to check them. This will effect acceleration. Dave ----
It's more of a "die out" than a bog on takeoff but it's sluggish/boggy at speed.
I plan on leaving the dist as it was since it starts and runs as is. I have no idea how the timing is currently set. I've never had to work on timing before so I'm a little intimidated but it needs to be checked. I've crawled around under the hood and can't see any timing marks on the pump housing/timing cover. The balancer does have a fresh white mark on it where it's apparently been done recently though...I just need to find the timing scale. It's pretty jammed up with radiator hoses and pulleys down there...
Yea that scale is a little important to do timing right.
Might be able to make a mark someplace to use a timing tape to check timing. Thing is you don't know where it is you are starting at so you could be 5* to 15* retard and why it has the bog and is a slug. Doing the above you would be able to tell if the advances work (I forgot vacuum advance before).
If everything else checks out you can try and bump the timing up by vac gauge or ear. Just don't go too far advance as it can cause issues.
Dave ----
Does this spacer gasket look correct? It leaves an air gap (bottom of top pic) that leads into the spacer channels and ultimately the carb barrel(s). Not sure if that's normal. The hose barb was connected to the PCV...
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