So it was a nice 36 degree day out yesterday in ohio and I wanted to take the Z for a spin. Well needless to say that would not start, it fired twice, but ran for maybe 10 seconds at most. I did some googling and couldn't find many answers. I've never owned a carborated car before and don't know where to start. The car is a 72 (45k miles) with an l28 that has the original 72 carboraters and I'm unsure if the have been rebuilt or not.
Any help is appreciated.
Cold weather Start issues
-
glacier985
- Posts: 390
- Joined: Fri Jul 18, 2003 4:30 pm
- Car: 72 Datsun 240Z
90 Nissan 240SX
11 Subaru WRX Wagon
16 Nissan Rogue - Location: Central Ohio
-
evildky
- Posts: 14225
- Joined: Sat Jan 31, 2004 9:23 pm
- Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW - Location: Louisville, KY
- Contact:
Re: Cold weather Start issues
so I assume the choke cable are properly adjusted an working properly? and when you started it you pulled the choke lever, turned key it fired and dies without you touchign the choke lever again?
-
glacier985
- Posts: 390
- Joined: Fri Jul 18, 2003 4:30 pm
- Car: 72 Datsun 240Z
90 Nissan 240SX
11 Subaru WRX Wagon
16 Nissan Rogue - Location: Central Ohio
Re: Cold weather Start issues
I really don't know about the choke cable being adjusted, but I did have it all the way back when starting the car and it died without me moving it or touching the gas pedal.evildky wrote:so I assume the choke cable are properly adjusted an working properly? and when you started it you pulled the choke lever, turned key it fired and dies without you touchign the choke lever again?
-
evildky
- Posts: 14225
- Joined: Sat Jan 31, 2004 9:23 pm
- Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW - Location: Louisville, KY
- Contact:
Re: Cold weather Start issues
with the leverforward the jets should be all the way up, when you pull the cable both jets shoud pull down abotu a 1/2 inch, I suggest you verify that they are both connected and moving abotu the same amount, have you tried starting with partial choke? you might simply be flooding the engine
-
glacier985
- Posts: 390
- Joined: Fri Jul 18, 2003 4:30 pm
- Car: 72 Datsun 240Z
90 Nissan 240SX
11 Subaru WRX Wagon
16 Nissan Rogue - Location: Central Ohio
Re: Cold weather Start issues
Should I also check the valve lash? I read a couple links from google that said something about incorrect valve lash can make the car hard to start. To me that seems like a possibility since the motor has a upgraded cam and I have no way of knowing when the valve lash was last checked.
-
evildky
- Posts: 14225
- Joined: Sat Jan 31, 2004 9:23 pm
- Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW - Location: Louisville, KY
- Contact:
Re: Cold weather Start issues
the valve lash was likely set when the cam was installed, it's unlikely the cause fo your issues, it's not difficult to do but I believe i'd start by verifying that the choke cables are adjusted properly, and that the pistons int he carbs move freely
-
glacier985
- Posts: 390
- Joined: Fri Jul 18, 2003 4:30 pm
- Car: 72 Datsun 240Z
90 Nissan 240SX
11 Subaru WRX Wagon
16 Nissan Rogue - Location: Central Ohio
Re: Cold weather Start issues
Back with some results, I found a lever that moves on both carbs when you move the choke. The lever moves in sync with both carbs. I took a couple pictures to show where it is depending on the choke position.
With the Choke all the way forward.
With the Choke all the way back
I wish I knew more about carbs, anything I've worked on before was fuel injected However I recenetly picked up the book How To Restore Your Datsun Z-Car. I'll be giving it a read to sometime soon.
With the Choke all the way forward.
With the Choke all the way back
I wish I knew more about carbs, anything I've worked on before was fuel injected However I recenetly picked up the book How To Restore Your Datsun Z-Car. I'll be giving it a read to sometime soon.
-
evildky
- Posts: 14225
- Joined: Sat Jan 31, 2004 9:23 pm
- Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW - Location: Louisville, KY
- Contact:
Re: Cold weather Start issues
these carbs are su's they aren't like traditional carbs, and they are a lot easier to deal with with the air box off
on top of each carb is a little thumb screw, that goes into the piston, there is a spring and fluid that regulates how fast the piston can move up, if you reach a finger into the hokle in fronf of the carb where the air comes in you will feel the side of that piston, you should be able to lift the piston up with your finger, sometimes after sitting they simply stick
where that choke cable attaches is just the linkage, that linkage leads to the jet, when you pull the choke pulls the jet out away fomr the needle (the needle is attached to the bottom of that piston) the needle is tapered so when the chocke is pulled and the jet lowers it lets more fuel flow around the needle, the jet itself has a thumbscrew for adjusting it in and out at idle but not somethign you should be dealing with yet
on the side of each carb is a fuel bowl, fuel enters the top and the internal level is regulated by a float and needle valve, the float is synthetic and can deteriorate over time along with any bits that make it through the filter can clof the fuel bowl outlet, at the bottom of the fuel bowl is a small ruber hose that leads over to the jet, this hose can be come clogged and fuel moves from the bowl to the carb by way of gravity and vacum so it doesn't take much of a clok to make it not work
I would first make sure the pistons move freely, and if they do I'd lift them up and spray a little starting fluid in each carb and crank it and see if it fires, it should, but if it does quickly you likely have a fuel clog in the bowl of the fuel line
on top of each carb is a little thumb screw, that goes into the piston, there is a spring and fluid that regulates how fast the piston can move up, if you reach a finger into the hokle in fronf of the carb where the air comes in you will feel the side of that piston, you should be able to lift the piston up with your finger, sometimes after sitting they simply stick
where that choke cable attaches is just the linkage, that linkage leads to the jet, when you pull the choke pulls the jet out away fomr the needle (the needle is attached to the bottom of that piston) the needle is tapered so when the chocke is pulled and the jet lowers it lets more fuel flow around the needle, the jet itself has a thumbscrew for adjusting it in and out at idle but not somethign you should be dealing with yet
on the side of each carb is a fuel bowl, fuel enters the top and the internal level is regulated by a float and needle valve, the float is synthetic and can deteriorate over time along with any bits that make it through the filter can clof the fuel bowl outlet, at the bottom of the fuel bowl is a small ruber hose that leads over to the jet, this hose can be come clogged and fuel moves from the bowl to the carb by way of gravity and vacum so it doesn't take much of a clok to make it not work
I would first make sure the pistons move freely, and if they do I'd lift them up and spray a little starting fluid in each carb and crank it and see if it fires, it should, but if it does quickly you likely have a fuel clog in the bowl of the fuel line