Hard to start and weird to drive 240z

[Reverend]

See this video http://s578.photobucket.com/albums/ss224/Spacereverend/?action=view&current=Video0012.mp4

It explains the symptom better than 1000 words. Sorry for the bad quality (and the video is sideways) but i think you'll hear what i mean. It stalls when throttle engaged. In the end of the video it backfires when i tried to accelerate it rapidly but the bang was so big that it muted the microphone for few seconds

Edit:

How much gas there usually is on the fuel filter? In mine there is about half inch. Before that video i needed to manually operate fuel pump before getting it started.

Edited June 14, 2010 by Reverend

[Reverend]

Anyone?

[Gary in NJ]

I keep coming back to the throttle plate shafts. Did you ever actually check them? Did you change anything on the balance tube? It sure does sound like a vacuum leak to me.

[Reverend]

Throttle plate shafts seemed okay. Rear carb was behaving strange sometimes, it stayed about 5mm higher than front carb after reving..needle was straight when i last checked it.

I've been discussing this same thing in other threads also and i tried to move the vacuum advance as suggested by sucking in the pipe that goes to dizzy. It didnt move a bit. So i'll start by renewing that

So where i can get new vacuum advance? I searched BD's and Motorsport auto but i didn't find them..

[Reverend]

Next thing i do is set timing right. How..? I have no idea. I have the chance to do it by myself or take it to expensive mechanic. I'd rather do it myself.

So im asking for you mighty Z-wizards to explain how to properly set the correct timing. Also does it effect on timing if you remove all smog equipment? I havent yet done that but i just might do that someday.

[1970Datsun240z]

Hey El Reverendo,

Do you have a timing light and/or a dwell meter?

Also I would recommend getting a Haynes repair manual like the one I have pictured. This has helped me out a bunch.

I have all my smog equipment removed and I would imagine that it would affect the timing if you were to remove it after adjusting your timing. But I'm not entirely sure on that one.

John

Edited June 24, 2010 by 1970Datsun240z

[Gary in NJ]

How..? I have no idea. I have the chance to do it by myself or take it to expensive mechanic. I'd rather do it myself.

Do it yourself because it's easy AND fun. Once you own the equipment, it's free.

1. Locate the timing mark on the harmonic balancer and mark it with paint, or white-out, or grease pen, or anything you have that will stick. This will make the job much easier.

2. Warm the engine up. Make sure the idle is correct. Shut down the engine.

3. Disconnect the vacuum advance at the distributor. Plug the line (I use orange golf tee's - this way it stands out and I don't forget to reconnect it).

4. Loosen the bolt on the shaft about one full turn; the bolt is about 1/2 way down the shaft on the right-hand side (as viewed from the left side of the car).

5. Connect your timing gun/light (inductive clip on the #1 ignition wire near the spark plug. It will also have a pos. & neg. that connect to the battery terminals). Get the gun and wires arranged so they can't get tangled into any moving parts. For that matter, wear a short sleeved shirt too.

6. Start the engine. Get the gun about 6 inches from the timing marks (keep you hands and wires away from the fan and belt). The strobe light will flash just as the painted timing mark passes to timing tab. While observing the light and marks, slowly rotate the distributor cap back and forth until your painted mark is across from the timing tab.

7. Once you are happy with the setting, shut down the engine. Tighten the bolt on the distributor shaft and reconnect the vacuum advance.

8. Reset your idle and make any and all final adjustments - then re-check the timing one last time.

Edited June 24, 2010 by Gary in NJ

[tlorber]

I say close the hood on the car and take a new pic for your avatar! Could be just bad kharma.

If indeed you find it is the carbs, you might ask Z therapy about buying just the rebuilt throttle bodies. I did this from them for my roadster and it was less than 1/2 the cost of the entire carb setup.

[Reverend]

I say close the hood on the car and take a new pic for your avatar! Could be just bad kharma.

Might as well be I started to dismantle all smog equipment after consulting few "old skool" mechanics. Im quite sure it have some positive effect on engine behaviour even it might not solve the actual problem. After that i'll check timing.

Now im stuck in this situation: i was trying to remove the air injector tubes along the manifold but they are rusted in place.. Im quite sure theyll snap broken if i try to use too much power.

[Reverend]

Little update. I needed to make this DIY patent in order to move the car to it's new home. I've removed everything except that injector tubes and air pump (its not connected anymore). Car starts okay and runs better than before. Carbs are running VERY lean atm but it's somewhat drivable.

BUT now it leaks exhaust or something from the engine, im quite sure that my patent doesn't leak. If car is runned inside, you have to wear gasmask. Its that bad.

I didnt have this problem before removing smog.

[Chris Thomas]

I have a 240z: new engine, new carbs, new fuel pump, new points, condenser and coil. Car start OK when cold (or after it has cooled down), but will not start after it get hot. I thought vapor-lock and put ice packs on the fuel line... didn't work. I'm really stumped... should I continue to look at the fuel system or the electrical system or what?