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 Post subject: purging the fuel system
PostPosted: Sun Jul 27, 2014 9:26 pm 
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OK I'm ready to get the beast started so I did the usual carb cleaner in the intake and I got a few backfires but I forgot to purge the air out of the new fuel hoses. I read that you're supposed to fill the float chambers. How do I do that?

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PostPosted: Sun Jul 27, 2014 9:46 pm 
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You don't. No need to.

The carbs will self-purge when the fuel reaches them. All you have to do is get the fuel up to them without burning up your starter motor.

Crank it for 5-6 seconds, let it cool for 15 seconds, try it again. And again.

Spraying starting fluid into one of the carb throats (while holding the vacuum piston UP and with the throttle OPEN) will let the engine start and run for a few seconds, which pumps the fuel you need to the bowls. From there it should start on its own, if everything is OK.

Always have a fire extinguisher and a cellphone at hand when you do this, and it helps to have someone else nearby, too.

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PostPosted: Sun Jul 27, 2014 10:20 pm 
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Roger on the fire extingisher.
I never do fuel related stuff without one.
OK then I'll keep cranking it. I repeated that about 5 times and gave up for the night.
I don't see a reason it wouldn't start other than I had the distributor off but it's in the same positon because you can only put it on one way.
All those new hoses just need to get filled up.

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PostPosted: Sun Jul 27, 2014 10:34 pm 
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If you've had your distributor off and you're getting "backfires" (technically a backfire goes out the exhaust pipe. You're probably describing a flashback, which is thru the carbs), please take a moment to check the wires and ENSURE the firing order is correct.

Cylinders are numbered 1-2-3-4-5-6 from the front of the engine to the back. The firing order on all L-series engines is 153624. (You can remember that easily if you think of how old you can be to enlist in the military; 15 is too young, 36 is too old, but 24 is OK). The #1 pin is at the front of the distributor cap, closest to the upper radiator hose, and the distributor rotates counter-clockwiZe.

Trace each plug wire to each plug to MAKE SURE they are correctly wired. It's easier to mess them up than you might expect. It's fast, it's free, and it might save you hours of frustration. Don't ask me how I know. :roll:


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PostPosted: Sun Jul 27, 2014 10:57 pm 
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That's great info!
Hmm sounds like you have some experience with frustration.
I didn't disconnect any wires from the cap. I just moved it out of the way so the firing order shouldn't have been altered. I'll keep at it this week.

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PostPosted: Sun Jul 27, 2014 11:02 pm 
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Have you EVER heard the engine run with this distributor cap? In other words, do you KNOW FOR SURE that it's wired correctly?

(Your answer will be your 100th post, BTW 8) )

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PostPosted: Mon Jul 28, 2014 5:37 am 
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100 :mrgreen:
Yes the engine ran great before I took anything apart.

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PostPosted: Mon Jul 28, 2014 10:23 am 
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["....the engine ran great before I took anything apart"]

Oh, how I lOVE that saying! :D I should have a plaque made of that.

If you're getting flashbacks or backfires, you have spark to at least one plug. (That doesn't mean you have proper timing, or that ALL the plugs are firing).

The SUs make it tough to spray starting fluid past them into the manifold, due to both the vacuum slide and the throttle plate having to be opened together to spray stuff in there. The angle is tough to work with and there isn't a lot of room, either.

When I was trying to get my Z started I found it easier to unplug one of the vacuum hoses on top of the intake manifold, and squirt fluid directly in there with a 'straw' attachment on the spray can noZZle. That will ensure at least 3 cylinders get fuel, which will let the engine run for a second or two. The running engine will pump fuel much faster than the starter motor will.

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PostPosted: Mon Jul 28, 2014 2:16 pm 
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Yes it's a very famous saying at my house too. I'm also a fan of "this should only take 10 minutes". My wife especially loves that one.
Outstanding advice using a vacuum port!
I hardly got any fluid past the slides.
That will also tell me if it's misfiring.
I can't wait to get home and give it a try.
I still think I'll disconnect the fuel hoses and hit the starter to get the air out.

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PostPosted: Mon Jul 28, 2014 2:27 pm 
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["....I'll disconnect the fuel hoses... to get the air out"].

Won't hurt, but it's completely unnecessary. When the fuel moves up the line from the tank, it pushes the air ahead of it. When the air reaches the SUs, the empty float bowls have the floats sitting at the bottom limit of their travel, which leaves both needle valves open. The air simply gets pushed into the empty float bowls and out thru the vents, until the fuel flows into the bowls.

HOWEVER, pulling the fuel line (after the pump) lets you flow-test the pump itself, to determine if the pump diaphragm is still doing a good job or not. You should get repeated pulses of good strong spray, not just a trickle or spits.

That's a two man operation and one of the understated dangers of it is getting your catch bottle involved with the moving fan blades. (Again, don't ask me how I know that :roll: ).

If you're concerned that the fuel needs help getting to the engine sooner, you can squirt the fuel filter full of good fuel with a rubber syringe (like an ear bulb squeeZe thingy). Just pop the hose off the INLET side of the filter bowl and squirt some good fuel in there. That also lets you see the fuel level in the filter bowl to judge if it's moving or not.

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PostPosted: Tue Jul 29, 2014 10:47 am 
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I didn't get a chance yesterday but will try again later today.
I have a spare original fuel pump if this ones not working well.
More great advice thanks.

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PostPosted: Wed Jul 30, 2014 7:34 pm 
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Well Mr Murphy paid a visit again.
I tried and tried turning it over to no avail.
The following tests were all done with new fuel.
I primed the carbs with a bulb syringe through the inlet hoses and still nothing.
I should at least get something with the carbs full right?
I disconnected the fuel in supply line and put it in a gas can then disconnected the carb inlet hose, turned it over and nothing came out. So the pump may not be working.
Will lack of fuel in it ruin the diaphragm?
It's got to be something simple I'm missing.

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PostPosted: Wed Jul 30, 2014 10:31 pm 
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Well, fuel does serve to keep certain parts wet. Lack of fuel in the pump *eventually* allows the diaphragm of some pumps to dry out, yes. Also, dry carbs can experience deteriorated gaskets and (I'm told) rubber seals. And old gasoline turns to varnish if given enough time. Those are all reasons I insist on running my Z several times during the winter.

So your pump may indeed be dead. Everything mechanical wears out eventually, so it's no big deal if it died. But if you successfully put good fuel into the bowls and still got no joy, I would suspect something else.

First, check to ensure you actually have a spark at the plugs. Not hard to do ~ pull a plug and put the spark plug wire back onto it, then lay it on top of the cam cover so the metal part of the plug grounds against the cover. Turn the engine over and watch for the spark. [If you don't get spark, we'll move back to the distributor]. If you have spark, take that opportunity to squirt some starting fluid directly into the spark plug hole, then replace the plug. Spin the starter and see if you detect any signs of life. If it tries to start, you can probably eliminate the ignition system and move back to the carbs.

Remove the top of one fuel bowl and look all the way down into the bottom of it, past the float. If you see water balls floating around in there, or if there is brown looking lacquer down there, you'll need to get it all out before your car will run. Take a peek and tell us what you see, then we'll go from there.

If it ran fine before you took it apart, and you haven't turned the jet screws at the bottom of the SUs since it ran last, don't mess with them now.

["I disconnected the fuel in supply line and put it in a gas can then disconnected the carb inlet hose..."] I'm trying to picture that....to test the pump you should disconnect the hose btwn the pump and the fuel rail, which technically would be the 'fuel OUT' line. A 'fuel IN' line would be btwn the fuel tank and the pump. Are we on the same page?

Can we know how long it has been since your Z last ran please? ALSO ~ I recall you installed a new fuel rail you got from Vinny? Yes? Did you blow compressed air thru it to make sure there were no insect nests blocking the tubes?

Frank

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PostPosted: Sat Aug 02, 2014 9:06 am 
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I love this. It's like a personal message conversation between two Z dudeZ, yet it is now available for the whole world to Zee.

You guyZ rock. Can't wait till I get my hands on a 70s Z. Some day. 8)



Side note: Webmaster/PreZ Hagani: this website IS backed up on a hard drive somewhere where no one but the Z Gods can access it, right?!? :roll:


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PostPosted: Sat Aug 02, 2014 10:16 am 
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This whole website is awesome-cool. 8)

When Ross formulated this Club, he had the foresight to ask the best Webmaster he knew (our Prez Jimmy) to set up a website which we could all communicate on. Over the years we have exchanged help and advice here and shared many joys and sorrows of Z ownership. The Club website helps to keep us (a *little* bit) sane over the Z-less winter months and, in doing so, has helped meld us into an extended family.

Jim did such a successful job with the CTZCC website, he was stalked by several other Z clubs (and one or two Dodge Neon clubs), who wanted to rent him or buy him or outright kidnap him to help get their club up to airspeed.

If you just read back over the years of this Tech Talk forum, you can find outstanding examples of scarred-knuckle Z owners, offering advice and the benefit of their own mistakes to newbie Z enthusiasts. I think I love this forum a little more than most of our other discussion topics. But it has served to instigate other great subjects of discussion, too.

Several years ago our Texas member Jim Arnett decided to photo-document his 1970 Z restoration project from start to finish, and suggested our now-present RESTORATION AND REPAIR TIPS forum. It has been a smashing success ever since, and we've met a lot of very interesting members who have joined from far-off places with great restoration tips because Jim started that forum.

And Ross instigated our current CONCERN FOR MEMBERS forum, where we try to watch out for each other during times of personal trials. It has taken us to a few hospital bedsides and a few funerals, but has pulled us more tightly together as a Z family.

And AirJockie had some bad experiences with a few of his local vendors and decided to warn us not to trust our Zs with them. His honesty resulted in our present VENDOR RAVES AND GRIPES forum, which has become a well-trusted guide for Z owners looking for outside services.

Casual readers who stumble over this website find SO much traffic on it, they might think we are an "internet-only Z club", which exists only in hyperspace. In Z-desolate places around the globe, it must be difficult to imagine that a tiny little state like Connecticut has such an active Z Club that we all know each other, meet with each other, and still have the most-active Z website on the internet. More than 700 members. More than 600 cars. Most of us know most of us. Whenever any one of our members strays from the herd and wanders off to distant lands like Salt Lake City, this website helps keep us in touch, because "You can't quit a Free Club".
This whole Club rocks.

That's what you 'youngsters' are inheriting from us old guys.
Don't drop the torch when it's passed to you.

Frank T
Knuckle-busted Z owner

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