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hatepotholez

Engine only runs with starter fluid

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28 minutes ago, siteunseen said:

You can remove the valve and push the pin down and shouldn't be able to blow through it. Does that make  sense? Pin up you can blow through. Pin down no blow.

Makes sense. I believe the SU DVD used a vacuum tool to check if the needle and seat were good. 

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I got a bad valve from Ztherapy once, they source them from someone else I'm sure. The pin was too short to bottom out and seal off. Bruce overnighted me another one, no questions asked. They're top shelf folks in my book!

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hard to tell from the pics, but your carb bodies look a little dirty. grit is the enemy - it will make your pistons stick, and the tiniest bit will keep the float valve from seating correctly and because the float valve tip is rubber, a bit of grit (or rust particle) can get stuck in it. clean it and try again.

as for the float bowl gasket - glue it to the lid w/some rtv which will hold it in place for numerous float adjustments. otherwise you'll be miserable with a floppy, twisty thing that won't line up.

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Thanks for the pics showing the alignment pins. They look just like the ones used on the flat top carbs.

Hope you figure out why your float valve isn't sealing...

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17 hours ago, siteunseen said:

I got a bad valve from Ztherapy once, they source them from someone else I'm sure. The pin was too short to bottom out and seal off. Bruce overnighted me another one, no questions asked. They're top shelf folks in my book!

I don't doubt that, if it's the needle and seat then i'll call up Bruce. 

11 hours ago, rossiz said:

hard to tell from the pics, but your carb bodies look a little dirty. grit is the enemy - it will make your pistons stick, and the tiniest bit will keep the float valve from seating correctly and because the float valve tip is rubber, a bit of grit (or rust particle) can get stuck in it. clean it and try again.

as for the float bowl gasket - glue it to the lid w/some rtv which will hold it in place for numerous float adjustments. otherwise you'll be miserable with a floppy, twisty thing that won't line up.

Ya, the body is a little dirty. I'll go over it with a tooth brush, carb cleaner and a clean rag. 

When you place the RTV do you place it on the lid or on the bowl? 

 

11 hours ago, Captain Obvious said:

Thanks for the pics showing the alignment pins. They look just like the ones used on the flat top carbs.

Hope you figure out why your float valve isn't sealing...

no problem and thanks!

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2 hours ago, hatepotholez said:

as for the float bowl gasket - glue it to the lid w/some rtv which will hold it in place for numerous float adjustments. otherwise you'll be miserable with a floppy, twisty thing that won't line up.

The lid, from what I read.  I haven't done it myself yet, but the next time I will for sure.  Seems like someone would've made a better gasket by now, these cork ones are pretty much once or twice then replace.  I'll try the RTV like Rossi says. ;)

 If I remember right Permatex makes one for fuel.

Yes they do;

Permatex 85420 Permashield Fuel Resistant Gasket Dressing & Sealant, 2 oz Tube

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I've thought about that stuff but I think it's too thin for the float lids.  The cork is "cushiony".  I think a synthetic material like some oil pan gaskets are made from now, MSA performance gasket, would work.  It's thicker and has a light torque, like the float lids do.  If the http://www.240zrubberparts.com/ guy, Nick I think, could come up with something?  You can still get those gaskets from Nissan, but the kit has all the other stuff with it and it's about $15.  Ztherapy probably sales just the cork and I think RTV sticking them on is a great idea.  I've read about that before in a post that somebody that raced had written, John Coffey maybe?  

If your's aren't torn, put them in a book like Mark said, then RTV to the rescue!  I know I will when I take them off again, which I hope I never have to but we know that ain't happening. :D

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Before I had my carbs rebuilt a few months ago, I opened and resealed the float bowls several times to check floats and valves.  As mentioned, the thin cork gaskets are reusable to a point.  Replacements were just a dollar and change from my local Nissan dealer.   They do seem to prefer being handled by tiny hands and sometimes get a little twisty.  As with about everything else on a Z patience helps.

Dennis

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yes, fuel-resistant rtv and glue it to the lid - much easier to get it lined up w/the fastener holes when you have the lid in your hand. only need a thin bit of rtv, then put the lid back on w/fasteners just lightly snugged and your gasket will be glued on nice and flat. don't gloop the rtv all over and let it set w/the lid off, or you'll wind up w/a lumpy gasket that won't seal due to the high points.

it ain't rocket science, just be clean & patient and it'll be fine.

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On 4/1/2016 at 5:12 PM, siteunseen said:

Awe come on! Don't leave us hanging. Is everything okay? Runs like a "scalded" dog now? LOL

sorry for the long post...:unsure:

So getting a little frustrated with the Z.

I spent the last 2 days working on it, and barely made any progress. The car still won't stay on without help of the throttle and the distributor is completely out of it's range to get it running.

Carbs:

The front carb doesn't get gas into the bowls, I honestly don't know what I am doing wrong. I bought a new rebuild kit and rebuilt the carbs. I am getting gas to the front carb banjo but not into the bowl. The rear carb is getting gas just fine. I tested the needle on the front carb to make sure it works. I removed the float and had my friend sit in the car and rev the car up and down and saw plenty of gas come out, I then installed the float and lifted it up and no gas came out. This leads to me to think the float is the issue. I think when I install the float into the bowl it gets stuck in the up position then causing the needle to stop flowing gas. By the way I am inserting the float and then turning the plate clockwise so I can get it in. I cannot install the float/plate assembly without rotating the plate counterclockwise to get it out and then clockwise to get it in.

Timing:

I have a big issue with the timing. My distributor is completely off the range, by that I mean I have to literally rotate the distributor far past the lock down screw to get the car to run. When everything was aligned, #1cyl tdc, crank at the first mark, the tong was not at the 11:25 position. This is what made me drop the oil pump and realign the shaft.

Here's what I did/happened:

-Did valve adjustments, intake @.20mm and exhaust @.25mm.

-Put cyl 1 in TDC compression stroke, checked by inserting a screw driver and saw the piston is on top, checked cyl 1 lobes and they were up and to the side. Then saw the pointer was on the first timing mark(which can be unreliable) on the crankshaft pulley looking from the passenger side.

-dropped the oil pump and reinserted the distributor shaft and confirmed the tong was at the 11:25 position with the small offset pointing towards the radiator.

-installed the distributor, rotor was at the 8:10 position or the drivers side headlight direction looking from the drivers side. Installed plug wires in counter clock wise order 153624 with #1 spark plug wire right before the rotor.

-car still didn't run but kept kicking like it wanted too.

-moved all the wires counterclockwise by 1, this made it worse and the car didn't even try to start.

-checked for spark, which there was.

-put the wires back in the original position.

-removed the lock nut and rotated the distributor past the lock nut. Car runs and maintains to stay on with lite throttle application.

stumped at this point. 

photos are of the distributor with the car running. 

I appreciate any help with this, losing my hair at this point.

 

240z distributor 1.JPG

240z distributor 2.JPG

Edited by hatepotholez

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No timing light?  I don't see any measurements.  The engineers put those degree marks on for an important reason.  It's important.  If you've confirmed where zero is, with your screwdriver method, then you can set ignition timing to its correct spot.  If you set and measure spark at the correct spot then you don't have a timing issue anymore.  When you have that locked down then you'll know that your problems are somewhere else.  Best not to solve two problems at the same time.

You're lucky in that you have an engine that runs.  From here it's a matter of confirming what's right, and making the stuff that isn't, is.

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2 minutes ago, Zed Head said:

No timing light?  I don't see any measurements.  The engineers put those degree marks on for an important reason.  It's important.  If you've confirmed where zero is, with your screwdriver method, then you can set ignition timing to its correct spot.  If you set and measure spark at the correct spot then you don't have a timing issue anymore.  When you have that locked down then you'll know that your problems are somewhere else.  Best not to solve two problems at the same time.

You're lucky in that you have an engine that runs.  From here it's a matter of confirming what's right, and making the stuff that isn't, is.

 

I do have a timing light, but I didn't use it. I was under the assumption that if everything was at zero and aligned the car would atleast idle on it's own(granted the carbs are all set) and then I can use the timing light on it. But even then the engine won't stay on within the lock nut range.

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10 degrees is a good starting point.  Zero is not the best.  

Sounds like you have the right idea though.  Get the ignition timing right, then focus on the carbs.  But even there, if once carb doesn't have fuel, that's kind of a "needs to be fixed" thing right off the bat.

I'd focus on getting the carb to function properly (gas in the bowl), and setting the timing to 10 degrees.  That's a "should idle" point, then build off of that.

As far as setting timing, even if you have to squirt starting fluid and rev the engine up and down, you should be able to see where the low point is.  Set it to 10 and assume that it's right.  Sometimes you have to make an assumption and work with it for a while.

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2 minutes ago, Zed Head said:

10 degrees is a good starting point.  Zero is not the best.  

Sounds like you have the right idea though.  Get the ignition timing right, then focus on the carbs.  But even there, if once carb doesn't have fuel, that's kind of a "needs to be fixed" thing right off the bat.

I'd focus on getting the carb to function properly (gas in the bowl), and setting the timing to 10 degrees.  That's a "should idle" point, then build off of that.

As far as setting timing, even if you have to squirt starting fluid and rev the engine up and down, you should be able to see where the low point is.  Set it to 10 and assume that it's right.  Sometimes you have to make an assumption and work with it for a while.

Ok thanks that makes sense. So this would be the third mark on the crank pulley? And then center the distributor in the lock range? I am sorry i'm asking a lot of questions, new to classic cars.

I hope changing the front float will fix the no gas issue, it always stops working when I insert the float into the bowl. The float might not be aligned. 

 

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I wouldn't worry too much about where the distributor adjustments are, if the timing light shows you're right.  All you care about is when the spark happens, not where the nuts and bolts are.  Each mark is 5 degrees so the third should be 10.  10 degrees of advance will give you a faster stronger idle than zero.  Get that set and see if you can get it to idle on its own.  Then you can tweak and tune to make it work better.

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2 minutes ago, Zed Head said:

I wouldn't worry too much about where the distributor adjustments are, if the timing light shows you're right.  All you care about is when the spark happens, not where the nuts and bolts are.  Each mark is 5 degrees so the third should be 10.  10 degrees of advance will give you a faster stronger idle than zero.  Get that set and see if you can get it to idle on its own.  Then you can tweak and tune to make it work better.

ok thanks!

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Hi hatepotholez,

I'm jumping in here at your request. Forgive me if I'm covering old ground, just read the last page of the thread to get a feeling of your problems.

Your timing shaft sounds like it is correctly oriented. To verify, rotate the crank to TDC of #1. Pull the distributor cap and verify the rotor is pointing at the number 1 wire. I am assuming that the offset of the distributor timing shaft is on the correct side (not 180 degrees out of phase).

At this point verify you have disconnected the vacuum advance line and plugged it with a golf tee.

Now what I suspect your real problem is. Your car originally came with points ignition. It is common practice to swap out a distributor from a later Z to upgrade to an electronic ignition. Mine came with a '79 280ZX Automatic distributor. Unfortunately, the timing lockdown plate was changed sometime in the intervening years. Using a later distributor with an original lockdown plate will cause the problem you speak of. Also, it is possible to install the plate upside down. You may have either or both conditions.

I have the old lockdown plate and spent too much time trying configure things with the timing in the middle of the adjustment range. It ended up near an extreme end of the adjustment range when an inner, wiser voice told me to accept what works and to get on with my life.

Hope this helps and you can get back to solving your forward carb float problem. If you are still using the mechanical fuel pump, you can manually exercise the pump with the valve cover is removed. Verify you have generous flow with the banjo bolt removed. Then verify the holes in the banjo bolt itself flow freely and are not clogged.  

BTW, manually exercising the mechanical fuel pump is a great way to prime the carbs after a tear down. Saves the extended cranking needed with dry carbs. You should have the valve cover off then to verify oil is getting to the upper deck before starting anyway.

Hope this helps,

 

dj

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I'm playing around with my float levels also, if you can call it "playing".  It's a PITA to me. :(

I rebuilt mine after watching the ztherapy video.  Set the floats as they show on said video, WAY OFF!  After reading the world wide web plus a little more I found where ztherapy says to not do it the way the video shows, different valves won't hold the float up to measure .55" from inverted lid to float roof like I had mine.  Now the way is to let the float dangle down and slowly push up until you can't blow through the supply line.  I think I finally read where it should measure somewhere between 11mm 14mm from float roof to the lid.  I decided to scratch all that and put the float and lid on top of a small glass.  Measure down 23mm from the inside bottom of the lid, down the glass and make a mark.  Pour gas through the supply and get the floats at the 23mm line on the glass.  Here's where I got the idea, thanks @Jeff G 78

Oh yeah, when you're fooling with filling the float chambers a lot, I've found that removing the plugs and taking the coil wire off works fast and best for me.  Mr Warner's way also works good but I haven't removed my valve cover.

 

Edited by siteunseen
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1 hour ago, djwarner said:

Hi hatepotholez,

I'm jumping in here at your request. Forgive me if I'm covering old ground, just read the last page of the thread to get a feeling of your problems.

Your timing shaft sounds like it is correctly oriented. To verify, rotate the crank to TDC of #1. Pull the distributor cap and verify the rotor is pointing at the number 1 wire. I am assuming that the offset of the distributor timing shaft is on the correct side (not 180 degrees out of phase).

At this point verify you have disconnected the vacuum advance line and plugged it with a golf tee.

Now what I suspect your real problem is. Your car originally came with points ignition. It is common practice to swap out a distributor from a later Z to upgrade to an electronic ignition. Mine came with a '79 280ZX Automatic distributor. Unfortunately, the timing lockdown plate was changed sometime in the intervening years. Using a later distributor with an original lockdown plate will cause the problem you speak of. Also, it is possible to install the plate upside down. You may have either or both conditions.

I have the old lockdown plate and spent too much time trying configure things with the timing in the middle of the adjustment range. It ended up near an extreme end of the adjustment range when an inner, wiser voice told me to accept what works and to get on with my life.

Hope this helps and you can get back to solving your forward carb float problem. If you are still using the mechanical fuel pump, you can manually exercise the pump with the valve cover is removed. Verify you have generous flow with the banjo bolt removed. Then verify the holes in the banjo bolt itself flow freely and are not clogged.  

BTW, manually exercising the mechanical fuel pump is a great way to prime the carbs after a tear down. Saves the extended cranking needed with dry carbs. You should have the valve cover off then to verify oil is getting to the upper deck before starting anyway.

Hope this helps,

 

dj

Thank you DJ,

I have never considered the distributor being different. It does have points as those are new and I adjusted the gap per the FSM. I will remove the distributor and check the number on it to confirm if it's original. Also I wish the lock plate was upside down, it isn't as the marks on the plate and the marks on the distributor match. 

If the distributor is the original one, what else would it be? 

One thing I did not do is remove the vaccum line. The golf tee should be inserted when the engine is running and the timing light at 10 degreees btdc.

41 minutes ago, siteunseen said:

I'm playing around with my float levels also, if you can call it "playing".  It's a PITA to me. :(

I rebuilt mine after watching the ztherapy video.  Set the floats as they show on said video, WAY OFF!  After reading the world wide web plus a little more I found where ztherapy says to not do it the way the video shows, different valves won't hold the float up to measure .55" from inverted lid to float roof like I had mine.  Now the way is to let the float dangle down and slowly push up until you can't blow through the supply line.  I think I finally read where it should measure somewhere between 11mm 14mm from float roof to the lid.  I decided to scratch all that and put the float and lid on top of a small glass.  Measure down 23mm from the inside bottom of the lid, down the glass and make a mark.  Pour gas through the supply and get the floats at the 23mm line on the glass.  Here's where I got the idea, thanks @Jeff G 78

Oh yeah, when you're fooling with filling the float chambers a lot, I've found that removing the plugs and taking the coil wire off works fast and best for me.  Mr Warner's way also works good but I haven't removed my valve cover.

Thanks for the link.

The front bowl has driven me crazy. The crazy is part that the rear carb is fine, something happens when the float is put back into the bow. Either the float gets stuck or the pin comes out on one side. ughhh so frustrating. 

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12 minutes ago, hatepotholez said:

The front bowl has driven me crazy. The crazy is part that the rear carb is fine, something happens when the float is put back into the bow. Either the float gets stuck or the pin comes out on one side. ughhh so frustrating. 

I don't know if this will be helpful to you in any way but it's a simple trick to test the float "floatability".  On the lid there is a vent/overflow hose connector.  You can use those little red straws that come with aerosol cans like WD-40 to stick down that connector and then it rest on the float's roof.  With that you can see if the float is moving freely.  I actually left one in and watched it raise and lower ever so slightly while I revved the motor.

There should be a small tang coming off the floats hinge that keeps the float from dropping beyond the wall of the float chamber.  It hits the mounting "legs" where the pin goes in.  If it's bent wrong it'll make getting the float back in the chamber a little tough.  You can sort of eyeball the tang the pin rides on in this picture.  Before I learned the "Just SUs DVD" had some old instructions that are no good with the valves they now sell my tangs were ramped up almost to the top of the pin holes.  They should be way down like the picture.

float.png

 

That connections is closest to the carb body and looks similar to this only it stands straight up, vertically.

Image result for fuel hose connector

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35 minutes ago, hatepotholez said:

One thing I did not do is remove the vaccum line. The golf tee should be inserted when the engine is running and the timing light at 10 degreees btdc.

I'm scared of that radiator fan so I always put the golf tee inside the hose end off the distributor, not the end coming off the front carb, before I crank mine.  If you get those marks on the pulley facing down, you can slide under the car and paint those marks with White-Out or whatever to make them easier to see.  The first one from the left is 0, it's a little bigger notch also, then 5, 10, 15, 20 etc.

Image result for 240z timing marks

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