l16 hitachi cuts out

[ggzilla]

Its not the plug wires. They work fine, as evidenced when engine us cold.

[danfiveten]

So my old carb was pissing fuel when you idled, so it would run like shit, and you would have to burn off the fuel. I just noticed its missing a spring on the accelrator pump linkage, the metal bar that goes from the pump back, theres a spring on the new carb that goes down to a little spring holder by the idle adjust, my old carb, thats missing, the spot on the linkage is there for the spring, but no spring or anything.  Could that of caused me to be leaking extra fuel when i sit and idle? Since the spring is no longer there to pull down on the lever and keep the pump pulled up, without it its easy to push the pump down with even just your finger. 

 

Top circle shows missing spring on old carb, bottom shows spring on new carb, could that of caused it to be leaking fuel when it idled at lights and stuff?  If so im tempted to just put the old carb back on. 

[smoke]

I'm not seeing what you're looking at in those pics. Do you mean the spring that is on the accelerator pump arm?

 

The old carb was drooling from the accelerator pump squirter?

[danfiveten]

Yah on the pump arm, the old one was missing, so there was nothing pulling the arm back up, could that of caused it to be pissing fuel if the pump was vibrating around when you sit and idle?  Just thinking of possibilities here. Springs there for a reason isnt it?

[smoke]

That one acts as a throttle return spring on my carb, did you have an extra spring hooked up somewhere for that? The pump itself (the plunger) has a small spring inside of it to push it back up. Not saying it did not cause any issues with your old one, but I kinda doubt it.

[smoke]

Let's back up just a little bit, because I am getting lost. The new carb, it has a big dead spot off idle that you can't get rid of correct? Does it also idle really rough once it's warmed up?

[danfiveten]

New one idles perfec when warmed up, its just the dead spot after it warms up. Its just as soon as you get on the throttle it cuts out, if you pump it you can keep it alive and moving. When going under 30 when barley on throttle it almost feels like your dragging something behind the car, like its pulling on it from behind.  I got new wires, cap, and copper rotor coming in since some build up on the old cap and rotor.

 

 

 

The OLD carb the spring was missing, looked like it broke off, so the return spring was completly gone, nothing hooked up to the arm, just wondering if i barley pushed down on the pump it would go in, like the spring int he pump is weak, so im wondering if weak pump spring and loss of the return spring, if that could of caused it to slightly leak fuel when i was ideling, ?  Either that or the fuel bowl was over filling ?

 

  If everything i do doesnt fix the dead spot, im going to put the old carb back on after messing with it to see if it stops leaking fuel, because that will show somethigns wrong with the new carb. 

[smoke]

The very first thing I would do today is test the vacuum diaphragm on the distributor like Mike said. If that checks out good, then we can go from there. Process of elimination sort of thing.

[danfiveten]

I did that last night, seemed good, did it when i popped cap off to check points and stuff.  They had just a little bit of build up, but figured id order new cap and rotor anyway just in case to. 

[smoke]

Wow, that really seemed like it. I would go with accelerator pump, but that would not explain the lack of power at 30 mph like you describe.

[smoke]

Keep in mind that I am not completely ignoring the carb here, just in my experience, I have had a lot of 'carb problems' that turned out to be ign related. When you put a light on it, did you rev it a little and see that it was advance good?

[danfiveten]

Its not really a lack of power, just feels like something is dragging, which may be low spark or just the combination of cap,rotor, and the low end crappy plug wires i had purchased?  Im hopping when i repace the new copper cap and rotor, and ngk wires maybe i will notice a difference.  It seems like a throttle response issue of as soon as you get on the throttle its just a dead spot, but its not always the same spot, sometimes it doesnt do it, but it does most of the time as soon as you get on the gas.  Its very inconsistent, and only does it when its warm, and the idle kicks down.  

[67411sss]

I'm having a similar issue

Can I ask.. Have you sprayed starter fluid at the base(around the mounting of the carb) to see if they are any leaks, mine is leaky and it really is making it hard to get my 510 to idle and it has a hesitation/flat spot

[smoke]

Well, a weak spark or even a retarded spark will run better with a rich fuel mixture. I honestly think this is something pretty simple that is just being missed.

[danfiveten]

How i feel smoke, and when i used the timing light it was very erratic, so im hoping something with spark once the engine warms up and kicks down the idle, only thing i can thing of at this point sicne its pretty mucha  throttle response issue, so ill update once the new cap rotor and wires show up

 

And no leaks, i sprayed and have seen nothing, i had put new spacer and gaskets on and put it on as tight as i could go, the old carb was pissing fuel out of the bottom of it as well, so that was one thing i made sure of this time.  Mine idles fine, revs fine, drives fine except that spot where it feels like im pulling a trailer, its just the flat spot when i first get on the gas from a stop, or rolling after shes warmed up. Its annoying, and seems like the hotter she gets, the worse it gets.  I let her sit last night as i went in to fill a water bottle at walmart, and when i left after she sat about 5 mins, the problem felt even worse. 

[smoke]

On the the accelerator pump arm, have you tried moving the rod into the closest hole to the pivot point and see what effect that has?

[67411sss]

How is the camshaft? No flat spots or maybe something in the dizzy is worn? Fishing now..

[danfiveten]

Camshafts fine, im repalcing cap rotor and wires even though they all seem fine jsut inc ase. 

 

I put it in the closest hole, didnt make a difference. It wasnt at first, but i moved it since the original carb was that way hoping that would be the fix. Nope :( 

[67411sss]

I ask because exit64 roadster had an annoying flat spot at 2500 rpm thinking it was a carb problem when it ended up being dizzy related

[smoke]

Until we absolutely are 100% sure this is not a timing related issue, I kind of out of ideas.

[danfiveten]

Why i hope replacing the stuff makes a difference.  I called national carb, they want me to send the carb back if i dont fix the problem, but i ahve the roadster show in less than a month i cant back out of now that im being sponsored. Pissing me off. 

[danfiveten]

Yah i will update after that smoke. 

[smoke]

Like I said, if it starts getting down to the wire, I would be more than happy to grab some tools and come over, or meet you somewhere to help out. I think I could get it worked out if it was right in front of me.

[danfiveten]

Talked to Dan Hart, he still has his machine for plugging the car in from his old shop, going up there sunday, hopefully my new plug wires and cap and rotor show up by then, i also ordered through nissan a new condenser and points just in case, was 20 bucks, more expensive than rock auto lists, but for real old stock parts, id rather pay a bit more.  (even if the wife does kill me)   So sunday i will be taking her up to his place with my dad to see if whats going on. If anyone can figure it out its Dan, guys a freaking motor genius, dont think anyone in all his years of running his shop ever had issues with what he built, hell my lz 2.2 has around 300k on it and still doesnt smoke or burn or barley drip oil, and the su's he built me havent been tuned or adjusted in over 15 years and still run like new.  Glad he has time to see me since hes retired. 

[danfiveten]

Just saw that post smoke, it didnt update till now, if dan cant figure it out ill let you know, the guy has done everything for my dad over the years and is good, plus its nice he has a machine he can hook her up to, hopefully tell us right off the back.  He thinks its timing related as well from what i told him on the phone.