240z still not starting

[ninjazombiemaster]

Never mind. One of the floats was messed up, I fixed it. Its still running like crap though. Backfiring from the intake and exhaust. Ive got the nozzle at 2 turns. Though, again, I've tried it all over.

[madkaw]

Check and recheck firing order. Check and recheck timing. Check and recheck all electrical connections as mentioned above.

Fill out your signature so we don't have to guess what year and model

[ninjazombiemaster]

Its a 73 240z with a round top conversion. Ive checked the firing order like 6 times. Dont have a timing light at home though. Im strongly suspecting its with the tuning on the carbs. But I just cant get it right.. I'll start rechecking things.

[ninjazombiemaster]

Oh, and for anyone wondering. I snapped a phone pic of the spark plug I pulled out, they all looked about like that. Funny, I've only put maybe a thousand miles since I last pulled them, and they were like new. But its been a damn cold winter and I've been running way too rich. I'll wrench on it some more in the morning and let you guys know what happens.

[olzed]

It's running way too rich or there is poor intermittent spark. Or both.

[ninjazombiemaster]

Okay, worked a little more today and was able to make it run a little better with some adjustments. But more importantly, I found that while at idle, if I lift the front carb piston to shut it off, the car continues to run. But no matter what richness I have the front carb set to, if I lift the piston on the rear carb, the car dies. That should mean that the front carb isn't delivering fuel for some reason, right? Well I pulled off the float and it seems to move freely, and the bowl had fuel in it. I tinkered with the action of it a bit and put it back on when it seemed right. The problem persisted.. Maybe something got in the fuel hose to the nozzle while I had it apart, and blocked it? Doesnt seem right, because it couldn't backfire out that carb like it has if there wasnt fuel in the first place. Maybe the float level is wrong? Seemed the same as the other one, though. Any thoughts? I have to be getting to work.

Also, it sounds like the rear carb is pulling more air that the front, though I can feel the suction on both of them. I was able to drive it (slowly) to work today though, thats better than its been in weeks.

Edited January 19, 2013 by ninjazombiemaster
Update

[Stanley]

On the linkage between the carbs, close to the rear carb, there's an adjustment screw. Turn that to open more throttle on the front carb.

There's more to it than that as you know (see the video), but it's a start.

[ninjazombiemaster]

Yeah, I messed with that during my lunch break and go it to open a little. Didn't seem to help the problem with front carb not sustaining the car but it got it breathing. I'll keep working with it, like you said, its a start.

[pacemkr]

just a thought,

its off topic from the carb issues, but i was having similar problems on a car recently.

the contact that takes the voltage from the high tension lead to the rotor, inside the cap, is a graphite nib that is held in place by a very tiny spring.

the car i was dealing with, the spring had corroded and would not handle proper levels of voltage. car would start but that's it.

its a long shot, but worth a quick check.

saw that you checked your condenser, etc but this spring is so hidden it would be easy to miss.

cold winters really bring out the hidden skeletons in every car, stay positive you will fix it.

[ninjazombiemaster]

cold winters really bring out the hidden skeletons in every car, stay positive you will fix it.

I'll take a look at that, thanks. And no kidding on that one.

[madkaw]

sooo, you don't have a synchronizer of any kind? "one carb FEELS like it is pulling more air", that's a tuff way to tune carbs.

[ninjazombiemaster]

sooo, you don't have a synchronizer of any kind? "one carb FEELS like it is pulling more air", that's a tuff way to tune carbs.

Feels and sounds, Ive got a good ear. I do not, though I know its a good investment. they didnt used to be different, must've gotten knocked out of place on the rebuild. Im hoping thats where my problem lies. What stores would sell on of those airflow meters?