OK, I retimed the 71 240z, and then it started acting all funny. In my origional post about my car not having any power the car was running fine. Now it coughs gas out the carbs and dies.????
I ordered rebuild kits for the carbs, they'll be here monday. Could it be anything else that making it do this too?
Charles

 

When I turn the car on and let it idle, it will pop and then shut off. If I start is and hit the gas it will pop harder and shut off. It goes cough, and dies.

 

popping out the carbs means you are running lean. is it just a popping sound, or do you get the oh so impressive fireballs? your timing can also be an issue in this as well. also, are your carbs synched?

 

Just a thought...but with my old SU's, and
current Webers, if anything prevented enough gas to get into those float bowls,
the Z would start...idle....but then go the cough/pop/die route under throttle.
Usually got the opposite problem, something (like a fine hair) makes it into the fuel inlet jet at the bowl inlet, and it can't totally close. The fuel level slowly rose at idle and would start overflowing in the carb. Check your fuel bowl level via the sight glass?

 

Well I just got done "rebuilding" My carbs. That was a big waste of money. There wasn't anything wrong with the old seals and such, but I guess its good to have new ones in there. I'm gonna put them back on after it wuits raining.
Charles

 

With both the original SU's, and now the triple webers + 280 block, my 73-240 used to starve out esp. in hot weather under high load (4th or 5th). The old pump(s) whether mechanical or cheapo electric weren't filling the bowls as fast as the big jets were sucking the gas out, so the level slowly dropped until the car would buck, snort, and blast thru the carbs.

The Holley Blue was a great pump :-)
which has been in for over 10yrs. NO volume probs since...and I do use a small return line (the old original) to keep cool fuel always there at the carbs during hot idle/stop go, etc.....avoiding vapor lock (which could also be a prob).

 

Son of a gun!
OK so we've rebuilt the carbs, new plugs wires coil condensor and the points are good. Now it will start up, idle at like 500 and shut off. I have adjusted readjusted and started all over again on everything, and nothing seems to be working. The fuel pump is working awsome, new fuel filters. I don't see why its doing this. What the heck man. This should be a perfectly fine running car.
What the heck, any ideas?
Charles

 

From all the posts....it still sounds like it's running "lean". Any chance of air leaks in any of the hoses/diaphragms? Or, what about the big mixture adjustment nut that's under the SU carb? Don't know how stock your set-up is....but if the idle damper diaphragm leaks...used to be a factor when I had SU's.
When it does idle....does it idle smooth? Or just trundle and slowly die?

 

It idles perfectly, now. I took alittle time to start all over again sunday morning and now the car starts up, idles like a loud sexy car, but wont rev past 4000rmp? I think I know what thats all about but I could use some pointers on that one. If I go to the back of the car it smells like its running really rich. Other than those two things, looks like we got this one licked guys.
Thanks for the help.
Charles

 

On that note, what do your plugs look like now? Even modest rich/fouling...and she'll go flat around 5000 rpm, esp under load in the higher gears? New set of plugs might be a relatively cheap way to eliminate that possibility....unless you think you've found the cause. In any event, hope you can finally get the Z out.
The battery in my 73 is deader than a brick....but that's OK....it's actually still snowing here in Ontario, Canada as I type!!!

 

Yes...definitely opted for the remote regulator. You want it set for like 5psi or so (mine is that range for current webers, not sure what it should be for SU's though). Som folks have a small pressure guage installed as well, which would be handy, right on the regulator where I believe there is a spot for it. The adjustment is a slot/screw...so I'm sure you could make up something for adjustments, esp if you also had a gauge. BTW....I paid well over $200 CAD for my new pump (incl regulator) and $200 exactly for a used set (spare). Given that it's been 10yrs of inflation, your price doesn't seem bad......excellent pump.

 

Dear lord,
I went out to syncronize the carbs and they are in perfect sync, its just that they barely move the little float thing on the sync tool. The car definately isn't running lean, it kinda pops in the exhaust under load at high rpms, and the smell at the back of the car is so rich that you almost come to tears, and it burns your nose. I know that the adjustment peice on the bottom of the carbs is the mixture adjust, at least thats what the book says. I was wondering which way do I need to turn it to get it not to run so rich? I'm going to pick up my new points today. Dangit, its almost done! I took it out for a spin to see how she was doing, and that auto tranny shifts REALLY nice. I like it, but its not 5 speed that for sure.
Charles

 

I changed the points to some new ones and the car wont even F%&*ing stay running. It'll start and die, start and die, start, blow gas, and die.

 

OK,
I took off the lil face plate thing that you attach the air cleaner to to see what the hell was up. With the "mixture" adjusting nut on the bottom of the carbs where they were 1/8-1/2 turn out. The car turns on, coughs gas, and dies. With the nut all the way out, it turns on, coughs gas and dies in the same aproximate time span. It would be terably more simple to just scrap this whole motor and put in the 302 I plan on putting in over the summer sure, however I do not have the time to do that. This is my only damn car and I really need some inteligent answers of what is actually maybe going on. I ask, how can the car posibly be running lean, when it coughs enough gas to drive down my street. The thought is just not feesable. Is there anyone that has FIXED a problem like this, not just going through it.
Thank you,
Charles

 

Charles...where do you live? Just wondering who could take a first hand look at this vs over the internet. After 27years of owning my Z, I've been through a few of those probs....usually stubbing my toes kicking the tires and making up new words because it's so frustrating sometimes. If you have more than 1 problem happening at the same time (electrical, air/vacuum leak, fuel) it is really hard to shoot without someone looking at the car in its current state.
Especially if there is more than one prob compounding this. Agreed?
By the way - what do the plugs look like when you pull them? They gotta be fouled by now?

 

I totally agree with you george. I live in Austin Texas. Everybody that I've found with a z car like the 240, 260 or 280, have all done a V8 swap. So they have no experience in the L6 area. It sucks. I put brand new plugs in about two days ago, and they are pretty nasty looking now. Looks like they've been in there for awhile. Sorry about the last posts I made. I had gotten zero head way on the car and was venting. I'm gonna go edit them to kindness now.
Charles

 

Creator, I live in Whitby (the other side of Toronto from you). However...it might be worth giving Greg Whitehead a call or visit. Runs Whitehead Performance in North Toronto (Dufferin/Finch), supports at least 2 racing Z's, and has a bunch of competent Z mechs. He'll give you an honest opinion, and might be an easier trip. (Most of his guys are also OZC club members). Strongly advise giving him a shout first 416-665-2220 and see where you want to go from there?

ps - I ripped off all the stock SU/Hoses/Diaphragm crap in favour of triple webers.....and can't really complain since. Guess it was either that or a V8 decision at the time. The actual L6 is a great engine otherwise...esp with a few mods :-)