Kyre - you should look into a DSII swap (aka Duraspark swap) there's stuff in the sticky about it.

Basically, you originally had a computer-controlled carburetor & distributor... by removing the carburetor (and its solenoids) this is going to freak out the computer, resulting in it most likely locking the timing in at 10° BTDC and not advancing it as RPM increases... this will result in lackluster performance and crappy mileage.

Just something to look into......

 

The secondaries are supposed to be cracked a little bit. Some air and fuel is used at idle from the secondaries.

The reason for this is to keep the fuel in the rear bowl from going stale. If Grandma drove a vehicle with this type of carb, the fuel would never be used in the rear bowl, and it would get all gummed up. You also have to be careful that when you close the secondaries so they hit the throttle bore, that they don't stick. The tend to do that if you let them close all the way till they get jammed in the bore.

I am thinking this is more of a tweaking problem with the secondary adjustment. I would close them more that you have them now, but not all the way. And then open the mixture adjustment screws on the front of the carb a little bit to compensate for all the air that is being introduced at idle.

What gets me is how they did the adjustment. You have to take the carb off to get to it, what a pain.

 

Hello, well more bad news.

I removed the carb to adjust the secondary's and they were all the way closed. I opened them a little and closed them to make sure they were smooth, then back it out till only a hair of the transfer slot was showing. reinstalled and same thing, the only way to keep it running is to stuff the cloth into the secondary's closing them off.
seems the secondary's are getting to much air flow even with them being closed off completely at the plate.

When I stuff the cloth into the secondary's the idle wil stay high unless i pull a small corner of the cloth out leaving a tiny breathing hole. as long as it has this tiny breathing hole the idle goes to about 700 rpms and stays steady.

Anymore things I can try? BTW, the mixture screws are still at 1 1/2 turns out, the linkage cable is still not connected and the linkage is all the way down, the idle screw under main linkage is back all the way out so the linkage is resting shut, if opened enough to attach the cable the rpms go to high, unless i open the hole in the cloth of the secondary's.

can I completely disable the secondary's as I never go above 55, it's a 3 speed tranny?

 

Did you say you rebuilt this carb in the beginning of this thread? I hope you or someone else didn't take the screws out of the butterflies. These are set at the factory so they seat properly in the bores. And they are also staked on the back side(buggered up) so they won't fall out in the engine.

If the staking is gone, it's for sure someone has taken them out at one time, and that might be your problem. Sometimes you can loosen them up and fiddle with them to get them to close off better.

Another simple thing to try, it's happened to me before. Look at the linkage that is hooked to the secondaries on the pass side. This is at or near the arm that bumps against the screw you are adjusting underneath. There is a screw that takes a flathead screwdriver that bolts the little arm to the shaft of the secondaries, this is the little arm that the linkage rod goes in. With the carb mounted in place, loosen this screw and re-tighten it. For some reason I have had this screw bind things up and not let the secondaries close like they should.

Don't be chicken and not adjust the mixture screws on the front of the carb. As long as you keep track where you are at, you can certainly put them back. But the 1 1 /2 turns is just a starting point. If you want it to run it's best, you will need to adjust these some.

 

The screw I am talking about is #2 in the diagram below. I believe the stop screw is #19 from underneath. Clip #109 holds the rod from the secondary diaphragm.

 

Hi, thanks for the help, The plates I never touched when I rebuilt this carb, the fast idle screw on the passenger side is right now about 3/4 of the way out. I have adjusted this in and out with no real change unless I turn in way in.

When I had it running today, I removed the vacuum line from the pcv and closed it off at the back of the carb and noticed strong suction from the carb, I assumed that was normal. not much vacuum at all from the pcv side of the line tho. guessing thats normal as well.

Thanks again

 

block off all pcv and vacuum connectors. disconnect all of them until carb is tuned and working correctly.

i am thinking the only way letting more air into the engine (partially unblocking secondaries with cloth) could ever slow down the rpm, is if you have a vacuum leak somewhere. my idea ( lol idea meaning complete guestimate) is that there is a vacuum leak, and when the secondaries are clothed off, that cloth acts as a second choke, which gives more fuel for the vacuum leak happening elsewhere, and this is leading to higher rpms.





pcv/brakebooster/any and all vacuum lines must be capped until this problem is fixed.
also you must buy a vacuum gauge, and connect it, that should be the only vacuum port used right now.

 

OK this may be a really stupid question, but the vacuum line for the break booster? that is the line going to the block from behind the break master cylinder?

So take off ALL vacuum lines and block them all off? does that include blocking lines off on the carb and engine?

What I mean is should I block the vacuum line holes from both ends as I remove them?

 

Yes it should be a rather huge vacuum line going to the brake booster from the carb or right below the carb..

Well label them first, I didn't label mine very well and now they are all confused

Then if you block them with vacuum caps at the carb/vacuum manifold that should be only thing needed, and a vacuum gauge.

When tuning with a vacuum gauge, finding the highest possible vacuum reading (maybe 25 or so could be more could be less) is best, and then setting the mixture a bit leaner, reducing the vacuum reading just slightly (about 1 inches of vacuum lower after leaning).

It is difficult to set the final mixture without all of the vacuum lines attached, so leaning (after hitting max vacuum) is probably best to wait until reconnecting the vacuum lines 1 by 1 to see if there is any major issues/leaks with a particular vacuum line).

Reattaching the vacuum lines is 1000 times easier when they are all labelled Also vacuum caps are needed at the carb/ base of carb/ vacuum manifold. (and the vacuum gauge is also needed)

i hope it works!

 

OK< I removed all the vacuum lines and capped them all off, but still wont keep running because the secondary's are taking in far to much air, only way to keep the engine running is to cram cloth into the secondary barrels.

I cant find any vacuum leaks anywhere around the carb,

When I have the cloth in the secondary's and the engine is running it has spurts where it will rev up and then back down, it does this over and over so long as it is running, am I missing something else that could cause this?

 

"the engine is running it has spurts where it will rev up and then back down, "

This happened to me once when i had the idle mixture screw turned extremely out, it seems that air got around the mixture screw and threads and the idle surged/calmed and repeated.

How does the vacuum gauge read when this happens? What about the fuel pressure gauge?

 

This is definitely an overfueling issue.

The engine starts to stall, vacuum drops (no venturi effect drawing fuel) and as the engine builds vacuum it stalls again.

Why this happened all at once is a question.

Did you change the powervalve when you rebuilt the carb?
Try this experiment...
Get the engine running and slowly turn both idle screws in until they seat.

 

Not sure about the gauge reading, I am buying vacuum and fuel gauges today and will update that info, thanks

 

Yes I install a new powervalve during the rebuild, same number 6.5


the idle screw on the drivers side (throttle linkage) is all the way out and just setting on the linkage, the fast idle screw is the same, it is seated on the cam behind the choke housing.

 

Idle mix screws is what he meant.