SU Carb Guru Needed, at wits end!

[Ghettopoptart]

First of all, I recently purchased a 74 260z from a gentleman, the car is everything i've wanted in a Z car, with the exception of a running engine. I've read up TONS of "Search button" topics, and looked all through diagrams of these darn carbs but cannot seem to figure the damn things out.

The carbs that are on the car are a set of 3 screw bottle top SU's, im assuming late model 72's that the gentleman put on there, when i bought the car, he said i could fill the bowls of the carbs up with gas and it'd run like a champ and that it had only sat up for long enough for the gas to go slightly bad, but the fuel pump wasn't kicking on, so what i did was after purchasing said beautiful car, i went to my local autozone and bought a Mr.Gasket 5-7lb fuel pump, i am now getting fuel TO the carb, but couldn't get the car to run. The engine would just spin over, can spray fuel in it, and it runs off of that like a champ. But soon as the fuel dies out, so does the motor. So in screwing with these things ( not knowing what i was doing) i found out how the choke works on them, (the lever isn't working seemingly) i could pull down on the bottom of them , and the choke applys, i got in the car, and BAM fired right up, until the vibration of the engine closes the choke, and it dies, i let it sit for about 10 min running on its own on a nice warm day (65) and then let the slide back up, and it just died , even under constant rev. I just don't know what would cause that, for them to run perfect up until that point. It had SOME bad gas in it, but the bowls looked clean and so did inside of the carb and needle , no clog between the bowl and carb, due to being able to spray fuel between the both of them and it come out both sides. I just cannot figure it out, is this so simple that im overlooking whats going on?

HELP!

[240260280z]

Pull off the filter enclosure.

Reach into each carb with your finger.

Lift an drop each piston.

Do they move with the same resistance and drop the same (location at bottom of drop and "clunk" sound)

Under each carb is a knurled knob. Turn it all the way up until it stops then turn it back down two and a half turns.

Check that the mechanism which the chokes lift and drop (called the jet), can move freely. If not then remove each jet and clean it.

[Travel'n Man]

There is a HUGH educational value of using the sites "search" feature. Not only does the searcher get to find the answer to his or her question that has been covered at least 1000 times, but it also enables the searcher to stumble on other tidbits of valuable information about the subject on hand.

[Gary in NJ]

If you want to own a Z, you're gonna have to become an expert on SU's. The good news is that the carbs are about as simple as they come.

You will NEED a few tools to make the carbs work properly. A Unisyn carb sync can be found for ~$35. If you don't have a tech/dwell meter you'll need to get one.

Read up on the operation, care and feeding on the SU's. Better yet, get the SU DVD from Z-Therapy. Chances are you are going to have to disassemble some of the pieces of the carbs to clean lube and adjust them.

[Bruce Palmer]

Question: You're dropping the nozzles by hand to get the choking function to work. Do you have choke cables connected to the linkages on the sides of the carbs to do that? As often as not it's easy stuff that'll get ya.....

Another thought: If you have choke cables attached to the carbs and the PO didn't modify the ends of the 260 choke cables at the carb end correctly that could be impeding their ability to function effectively. Shoot some pics and email them to me at Sales@ztherapy.com and I will be glad to assist.

No way connected choke cables should not drop nozzles that can be dropped by hand, i.e. not varnished in place.....

Other running issues to be adressed later. Most of which are covered in the JUST SUs DVD.

[Ghettopoptart]

Still no change, im taking them off today and cleaning them out, hopefully they'll run right afterwards.

[Bruce Palmer]

Cleaning them out for what?

[Zedyone_kenobi]

Ghetto, you want some advice.

Be patient and LET BRUCE HELP YOU!

He is the man when it comes to SU's.

[Travel'n Man]

...........agreed with the above statement - nobody knows SU's better then Bruce and ZTherapy. You could have stopped up filters in the carbs if they are still in there - you could have floats not set right - you could have bad fuel - you could have bad fuel lines going from the float bowls - you could need new needles - you could have the valves turned the wrong direction - you could have your chokes set too tight..........the list kinda goes on for a long time.............ZTherapy can help you and send you the correct parts and pieces that you will need. Be sure to get a few extra float bowl gaskets - you will need a few extra to have on hand.

[esmit208]

I respect Bruces' expertise as well as the expertise of the other forum Z owners that contribute. A little known internal part is called a GROSE JET. Be sure to check the condition of those. GOOD LUCK!

[Bruce Palmer]

There are times that even I wish Grose Jets were still around. They were super simple and even though old Scott (over) sold them as the answer to a maidens prayer, they did work well, except on 4 cylinder engines.

[Ghettopoptart]

Alright, an update.

Problem has been solved. Before I Tell you what it was, let me apologize for being a good bit pig headed on the car, its tough working on something and coming inside in search of help all hot and bothered and just outright fussy. Again, apologies to the fullest.

The probled lied in when people told me to use the air fuel mixture screw on the bottom of the carb, and turn it counter clock wise. Like a moron i turned it clock wise , untill it bottomed out, and backed it out 2 and a half turns, while i had them back on after cleaning them up, i decided to relook at it, and noticed i wasn't turning CC before, i was turning Clockwise. so i turned them correctly. And it busted right off and runs like a champ. Stupid mistake on my part.