madkaw

Where do you figure your power band is at? do you have forged aluminum psitons? If you do have a 'race cam", how well do you think the SU carbs will keep up with it? Have you done a searching on the Datsun motors and their limits.

cool!

I got to say, when I decide to move on to FI, I will miss these carbs. Yes there is a little fiddling to do, but i'm a fiddlerLOL Once you get these tuned right they are a real joy and VERY streetable. These perform better then my SU's and have the added tunability and power not capable on the SU's. Don't bother wanting triple carbs unless you are willing to spend money on an O2 sensor(wideband) to do some real tuning. I know for a fact that my carbs run a lean 15-16AFR at cruise in 5th gear. 4th gear is more 14ish ready to pounce into the 13 teens in WOT application. Idle is almost where I want to make it. The car starts easiest with a rich idle-12-13, but the car will idle at 750rpm in the 17-18 range. The o2 sensor will also troubleshoot for the difference between ignition problems and maybe a loose jet;) My latest find of altering the bleed tubes has made these carbs smooth as FI. My red-loctite filler for the bleed holes did not hold up over the winter fuel emersion. Just one hole opening up on the bleed pipe was felt while driving. The transition hesistaion started again, and I immediately suspected the bleed pipes-and i was right. I need to experiment with solder and filling the little holes in the brass pipes. I might actually go a little further and temp fill a couple more holes to see how things react. The only thing to make these about perfect is to be able to come up with a closed element filter or an evap system to capture all the fuel fumes that come out of the huge bowl vents. My trick of turning off the gas and running the bowls dry BEFORE entering my garage cuts down on 90% of the fumes. Soon will by dyno time. I need to play with my timing some more. I'm going to butt tune for best power and then take it to the dyno. i'm running a fairly aggressive timing now, but might be able to step up a bit. The timing will be nice for off throttle and cruise conditions also. Shooting for about 50 degrees advance during cruise! Should be able to get some serious MPG at that rate. Thinking i wouldn't mind a set of 44's or 50's on a L28 with a big cam for fun. feeling pretty confident I could tune it well.

240=260 I thought as far as body. I thought the bumper was slightly wider and had a different angle for the fillers and that prohibited it from being brought in closer the body and looking correct. Like I said, my memory is questionable. I was trying to use 240 mounts on a 260 bumper too, so that's the difference-maybe. So if you just put the bumper up against the facia it tucks next to the body cleanly?

I believe I tried modifying or mounting a 260z bumper on my 240z years ago. The bumpers are shaped differently-subtle difference, but enough that it won't just contour to the body lines by bringing it in closer. The angle is different to compensate for the fillers used on that year. If my memory serves me right there was too many modifications that had to be done to the actual bumper itself to make it worth while. Example-cutting it at the center point to bring the angle in tighter to fit the body lines. My memory has failed me before, but I think it's a lot more then just modifying mounts

Hi Arne, glad the porsche has is staying fun-good luck

An experienced Z guy and a good tune up does wonders. Sounds like a good day!

Don't forget you don't have a stock motor so stock specs might not work for fuel.i wouldn't be afraid to go 2mm richer

Yep with a .044 gap

So what numbers did it dyno out. Don't be afraid to tweek those floats . These engines like a rich mixture I swear.

PM'd you

Sounds like a weak spark. Check voltage while running . Check all grounds and associated wiring . 10volts only at the coil?

I'd say you have a bad starter . It's hard to get a good remanufactured starter these days. It's better to have an original starter rebuilt at a local shop somewhere. I've gotten 2 bad ones in a row from autozone

Throw out bearing or something in the clutch let go. It's hard to nail down noises since they like to travel around these cars. Try the above suggestions regarding the clutch.

Yep- the crank will have to be positioned correctly, but it will come out of there

Fatten her up and feel the power :0

Starter was changed to fix this issue or the issue started after new starter?

Mike If you are interested I will send you my dizzy complete with coil module everything that worked perfectly before I took it off a month ago. I would suspect your ignition, but this would eliminate that part of it. PM me if you want to try it. I believe my set up is from an 81

Just had some thick black plastic laying around and RTV'd it to the opening under the panel.

So all this time the majority of my issue has been the interior hatch panel not be sealed . It is night an day difference now that I have put plastic underneath the panel and sealed things off. It's not perfect but 99% better. So I am going to go along with all those folks that say it's nothing to do with exhaust tip length or lack of spoiler - it's an exhaust leak.

I would say it's time to eliminate the fuel system. either drop the tank or just drain it into a pan to see what gives. Pull the fuel sending unit and check both supply and return-blow thru both. I would remove the fuel rail an make sure the return side is not obstructed. Pull the inlet sides of the SU float bowls and check the filter there. Also check the fuel hoses from the float bowls to the carbs to make sure they are not collapsing under heat. The ignition next Good luck

I have heard more pros then cons on the additives. It's more of a matter whether it will fix the problem then doing damage. IMHO I would give it a shot!

Well I have been driving my Z around for a couple of weeks now with no dizzy-seems weird. I have a lot of tuning to do, but it will be clean laptop type tuning:cool: I used some basic timing specs based on how my zx dizzy was curved to get me in the ballpark. I need to tack my 17 year old son with me to punch in numbers as I am driving to dial it in better. But right now, it starts easy, idles perfect and has as much power as before. The lack of wires associated with the old ignition set-up sure cleans things up.

Well I'm going to tag on to this older thread because I think Derek had the best idea for trouble shooting this issue. I had actually bought a fog machine over a year ago when they were cheap(after the hallowen holiday). It really is a cheap, fast clean way to diagnose the exhaust fumes. I tried the "suck" method first, but it left too much to question. Inside the car with not much room to move around and it being dark, it was too hard to tell where the fumes originated from. Now the "blow" method was much better. It really only takes a couple of minutes to set things up and start trouble shooting. What I found and yet to be fixed, is that I have a lot of air moving thru the latch assembly. It looked like a steam engine coming out of there. Perfect spot to suck up those swirling fumes around the back. I haven't finished examining everything yet, but the only way fumes have access thru this point is by leaking around the vinyl panel on the hatch. The low pressure in the cabin must be sucking air around this panel(which is NOT air tight-mine anyway) and thru the hatch assembly. It would seem to me that the easiest fix here would be to seal the hatch panel by sealing some plastic sheet behind it-agree? I also noticed smoke around the left tail light , where some previous bodywork was done. Also noticed a lot of smoke out the pillar vents, but I think they are too far from the exhaust to be sucking anything in. I will update as I try to fix these

Like John said and that you admitted of not doing the proper bleeding of the MC. You will be chasing your tail if you don't eliminate that first. There could be many possibilities but always suspect air. If you have been bleeding the brakes by yourself with a vacuum, then get someone to help you do it the old fashoned way-pump,pump,bleed!!