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Engine only runs with starter fluid

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I follow the same basic procedure as Mark. I just use a straight edge across the needle shoulder and piston bottom to get the needles flush. Sometimes I'll use the edge of a Vernier caliper if I want to lean out the idle a bit by having the Needle shoulder protrude by about .020" from the Piston bottom.

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a rebuild kit from ztherapy is cheap and well worth it. the floats are the most critical initial adjustment, as they set the fuel level at the nozzles. the float needle valves can be finicky so replacement is the ticket - they come w/the kit.

 

you'll be taking the float chamber tops off a bunch of times to get them adjusted - stick the float chamber gaskets to the lids w/some gasket cement so they don't pringle and become impossible to align

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When you order the kits, assuming they're coming from ZTherapy, get the "SUs only" DVD too. The knowledge shared in this DVD will take any guess work out of the rebuild. 

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When you order the kits, assuming they're coming from ZTherapy, get the "SUs only" DVD too. The knowledge shared in this DVD will take any guess work out of the rebuild. 

Absolutely!

 

The Just SUs DVD came with my rebuild kits, $180 I believe.  Well worth it, new nozzles and hoses are hard to find.  The DVD talks about Grose Valves with a ball instead of the pins but they no longer make those so you get the valves with pins.  It's kind of funny hearing him talk about how much better the Grose Valves are compared to the pins.  No big deal though.

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Here's my approach on adjusting the floats.

 

 

http://jarvas240z.blogspot.com/2013/06/carb-float-levels-sightglass.html

Thanks for that Dave.

 

I have my carbs and intake screwed to the wall above my work bench.  I am going to set the levels the best I can before putting them on the car.  I need all the information I can get.  :D

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Thanks everyone for the advice. I ordered a japanese kit from zcardepot. I should have ordered the dvd from Ztherapy but was in a rush.

I do have a few questions. What is the procedure to temove each carb from the thottle, how do I separate the float bowl from the main carb body and how do I adjust the linkages?

Thanks!

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There's tons of stuff on youtube.com about SUs.  They really are simple.

 

Take the 8 nuts off the intake studs, 4 per carb, and the whole assembly will slide right off.  The only connections are the fuel lines and the vacuum advance tube on the front carb.

 

Take a bunch of pictures as you disassemble them.  Two separate piles, they are the same but opposite like looking in a mirror.  :)

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IMO It's not necessary to separate the float bowl from the body unless it's leaking fuel from the connection.

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IMO It's not necessary to separate the float bowl from the body unless it's leaking fuel from the connection.

No, not at all.

 

I did it so shining them up would be easier.  :D

 

If they do leak there's a way to swap that rubber piece around.  I'd have to skim through the DVD to remember how.

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IMO It's not necessary to separate the float bowl from the body unless it's leaking fuel from the connection.

 

I understand, the only issue i'm having is when I try to put the float assembly back in I have a slight bit of twisting that has to happen. I am unsure if that twisting action changes the settings on the float. I would rather drop it in from the top directly. 

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 I don't remember having to do much twisting on four screw carbs. I've been told that three screw carbs require rotation to remove the tops. Unless there is considerable resistance, I doubt that the float setting will be changed. By removing the suction chamber and piston you can see the fuel level in the nozzle to double check the height. I have never used this method & I don't remember how far below the top of the nozzle the fuel is supposed to be. Anyone want to chime in and add some info?

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Ok, made some progress. The carbs didn't need rebuilding, the spark plugs were just really wet. Remarkably it ran very good but at high rpms. I still have a timing issue I have to deal with  :angry: I am guessing the oil pump is not aligned and I have to take it out and align it. Once the timing is done I will try and sync and tune the carbs.

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Quick update, I haven't solved this issue.

I wanted to know how to check for a weak fuel pump? I hand pumped the fuel pump and it squirted out fuel. I put it back in the car but nothing. I let the car sit over a month and the fuel level in the filter is near the bottom, I crank and see fluid gushing inside but it will not raise to the top to the output. I ordered a fuel pump from rockauto just to try it out.

 

 

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If you have screens on the carbs banjo bolts they may be restricting the flow. Mine never completely fills my glass filter after the pump. Probably not the oe one on the passenger's fender either.

You might put a gauge on the end of the supply side coming off the pump and see what it reads? Either turning the motor with the starter or working the arm by hand. You could get a cheap gauge at Lowes in the pool filter section.

 

 

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There is an eccentric that runs the fuel pump. Is yours tightened and good. If you take the valve cover off you should be able to see the eccentric pump the fuel pump using a remote starter. Make sure the car won't start or it will make an oily mess. 

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The eccentric is the arm that goes against the off center cup on the cam sprocket bolt, right? I've wondered if that off centered cup came unwelded from the washer would the  pump still work? It wouldn't would it? Just curious.

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Actually the off center cup is the eccentric that goes against the lever. If the bolt is loose or the cup were to break somehow the pump would quit working. If the pump is working, unhook all the lines from the exit port. Check for flow, add one line back at a time checking for flow. When the flow stops, find the reason, there is the problem...

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so a little update. 

Car is running on it's own but only will stay on if choke is on.

Some things I did.

-installed a new mechanical fuel pump.

-adjusted floats to be parallel to lid cover per SU DVD.

-installed new needle and seats, end of line screens, fuel pipes and hoses.

-adjusted idle nuts to 2.5 turns.

 

I am still noticing gas leaking from the rear carb vents. This does happen after 10 minutes, compared to 5 minutes before the carb work. I will check the rear float again. 

The front damper is not dropping down. I cleaned the needle but it seems the issue is not between the nozzle and needle but with the pot and damper. 

Gas is coming out of rear carb's throttle area. The damper action is perfect, it goes up and down with engine vacuum unlike the front one.

 

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 Needing the choke when the engine is warm is a sure sign of a lean mixture. Inadequate fuel supply, wrong float setting, are a couple of the more obvious reasons. They may need the mixture adjustments opened up 1/4-1/2 turn more, however, the overflowing carb and the sticking piston have to corrected first.

 Does the piston stick at the bottom of it's stroke? If so, it is likely nozzle misalignment. When aligning the nozzles, adjust them to the top. That way when you drop the nozzle screws down 2 1/2 turns later, you'll have a little extra clearance to ensure the needles don't stick in the nozzles. 

 If the piston is sticking higher up, carefully inspect the damper and chamber for scratches and or dents. Not only is the piston supposed to drop but it should drop at the same rate as the other carb.

 The overflowing float bowl is likely caused by a defective float, float pivot or too much pressure. (You already replaced the needle and seat) One way or another the needle and seat are not closing the fuel off when the float raises.

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On 3/14/2016 at 4:03 PM, Mark Maras said:

 Needing the choke when the engine is warm is a sure sign of a lean mixture. Inadequate fuel supply, wrong float setting, are a couple of the more obvious reasons. They may need the mixture adjustments opened up 1/4-1/2 turn more, however, the overflowing carb and the sticking piston have to corrected first.

 Does the piston stick at the bottom of it's stroke? If so, it is likely nozzle misalignment. When aligning the nozzles, adjust them to the top. That way when you drop the nozzle screws down 2 1/2 turns later, you'll have a little extra clearance to ensure the needles don't stick in the nozzles. 

 If the piston is sticking higher up, carefully inspect the damper and chamber for scratches and or dents. Not only is the piston supposed to drop but it should drop at the same rate as the other carb.

 The overflowing float bowl is likely caused by a defective float, float pivot or too much pressure. (You already replaced the needle and seat) One way or another the needle and seat are not closing the fuel off when the float raises.

 

Ok more progress.

 

I rechecked the rear float, it looks the pin was half way out. I carefully reinstalled the float and no more leak.

 

Now the front damper is a real pain. The damper drops perfectly into the nozzle, theirs a nice fast clunk so no issues there. The issue is the pot and the damper. I was using emory cloth on most of the areas and got it to be perfect in my hands, but when installed it would not drop at all and stick. Then I went at it again with emory cloth and WD40 and like an idiot I dropped the plunger and the pot on concrete. Now even though with the sanding the assembly goes up and down perfectly in my hand it does not when installed on the carb. 

When is the choke activated? When the handle is up or down? 

 

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