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Stalling issue(under throttle)

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Car runs and idles. Driving was the issue. The car would sputter under throttle. The car has about an 1/8th of a tank of gas. Could that be my issue all along? Never had any issue with the car doing 45-1hr trips in Florida April may heat. I have been reading the dirty su carb tuning. I will try some and try to drive it tomorrow. 

The battery issue is prob from the push button ignition or cig lighter. 

The electronic distributor parts were brought up and I figured changing them out anyway. 

Thanks again,

Chris 

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Restored a mk1 Sprite for some dude once, gave the car to him, the same week he started messing with a push button starter, he ended up mixing things up so much that the battery reversed its polarity.

 

Don’t even want to open up that car anymore , shame it was a great car to drive tops off.

 

Here’s an SU manual:

http://libgen.io/book/index.php?md5=650D1EFFD49B448501385D3E7FFB0444

 

Sent from my iPhone using Classic Zcar Club mobile

 

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Just played with the adjustment. Seams like the carbs are pulling the same. I will have to take the car out for a drive tomorrow. I have my mechanic friend coming to check out the battery issue. Car idles at 1k. Cant get that lower unless I am doing it wrong. Going by the dirty su adjustment. They both suck the same. The balance screw was down about 3/8" inch and when bliping the throttle the front car did nothing. I backed that out and now the balance screw / bar is sloppy but both make the sucking sound. 

I have yet to adjust the rich lean screws. Have not been able to drive. I am going to get new gas and put some in for the ride tomorrow. See what happens. 

Should the balance bar set screws be "sloppy loose"

Thanks again everyone. 

 

Chris 

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There should always be a small amount of slop in the linkage so the pedal itself is never holding the carbs open. So, "sloppy loose" may be too much, but "some play" is correct. The center screw up on the balance tube is "idle speed", and the screw on the rear carb is "idle balance". The screw on the front carb is only to control how much "throttle boost" is applied by the throttle opener system, but since your throttle opener system is completely disconnected, it should have no effect.

When you say "rich-lean screws" what are you talking about? Are you talking about the nozzle height adjustments under the carbs?

Sure wish I were closer... We'd have you fixed up in short order.   :geek:

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Same here. I'll fly you in for a weekend. Hahaha

Yes the adjustment screws on the bottom of the carbs. I was just tinkering with items and when I adjust the nozzle height nothing changes on the rear carb. I do notice the hose going to the float bowl is stuck. The one that is connected to the choke cable. And typing this probably means I have the choke cables connected while adjusting...The rear carb is cleaned. I set the needle height. The air coming from both carbs is set,(using this term lightly) to 5 on the syncroguage. Not using the unisyn. 

I am going through and reading the carb tuning adjustment threads. I need to watch some videos. 

On the rear carb no matter where the adjustment screw is the car stalls when I pick the the piston. The front carb ig elevates and settles out. The rear always wants to die. 

Chris

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LOL. I do get down to Boca every now and again, and I already looked up the travel time at about two hours each way.

Have you verified (using the clear tube method) that your float levels are close to spec?

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No I have not. I need to do that and read read read the several pages I have marked about the SU. I picked up tube but way to big. Need some smaller hose. I found the picture with the coat hanger and marking the bowl at 23mm from top of bowl. 

Boca not far from Marco hahaha. 

Does anyone have contact info for Ztherapy. I would like to see if they have the Just Su DVD hell I'll buy a VHS and tube tv... 

Chris 

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Ztherapy is on the web here >> http://www.ztherapy.com/  I'm sure you can buy the SU video from them. If you hit the "customer support" link, and then hit the "video" link, there's some talk about costs and stuff. But best to call them and order it over the phone.

I'm assuming this is the clear tube measurement you mentioned with the coat hanger?

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So you're on Marco? My neighbor just got back from there. Her was there for two weeks for vacation. Told me it was fantastic!

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It's been a minute.  I have been busy with work and no time to play. I received the fuel gauge and t for testing. I took a video. I am starting to believe my issue is in the rear of the car. Thoughts on video?

Chris 

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Video is the cad running and the gauge bouncing back and forth very rapid. Should the gauge be constant with the fuel psi? 

Chris

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That's a cheap gauge, with no damping.  The needle bounce is amplified.  Probably not a big deal to the carbs.  Hard to tell what real pressure is, but it looks about 4.5 to 5 psi.  An oil-filled gauge will give a smoother reading.

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I thought that as well. I will get one of those. I have a fuellab from my old 350z. It goes to a 100psi. Maybe a constant reading. With a better gauge is this something normal?  Jumping? Or could this be a fuel pump issue?

Thanks guys. 

Chris

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Well I am back... busy with my business and figured I would tinker(bc looking at non running beauty kills me). It takes work to get a to start after it sits for a while. Once I did start it and adjust idle screw(still no ztherapy dvd) my fuel gauge would read 3-4 psi. Once warm and idling rough(I feel) and at 750-800 it was below 3psi. I have never dropped the tank nor changed the fuel pump. I have changed the filter from the tank pictured earlier. Would I gain or narrow anything by routing a line direct from the filter to the hard lines in the engine bay and the return direct to tank? Eliminate the hard lines under the car for a test? Change the fuel pump for a new one? 

Still searching for an answer for the ole girl. 

Chris 

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is it idling OK now?

 

Going back to the beginning, it seems to me that this was the sequence, right:

1. car was all working fine,

2. you took carbs off to fit new exhaust

3. You fitted the exhaust and put the carbs back on

4. The car ran poorly

5. You fiddled with float levels, mixture screws and more

5. Eventually discovered that the carb linkage was not set right and front carb wasn't opening at all below 2k

 

I personally think it's unlikely that you simultaneously developed problems with fuel supply or ignition. Fwiw that 2 psi fuel pressure is fine.

 

I think all you've got to do is really balance the carbs properly (you don't need Ztherapy for this) and make sure those float levels and mixture settings are right.

Colourtune is a great tool to help with the mixture.

 

Eventually you will need a decent heat shield between that zstory manifold and the carbs. Without it the fuel in the float chambers will boil.

 

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@7tooZ thank you so much for the DVD. I'll be watching it and I'll see where I went wrong. I am going to toy with this end of the engine then further investigate before tearing parts off. 

Love the Z community!!!

Thank you,

Chris

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On 4/11/2019 at 8:04 PM, 7tooZ said:

Pass it on when you can. 

I will. Thank you again. Watching between GoT episodes Haha. Already learned so much from first hour. I will be taking carbs off and cleaning again. 

Chris 

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