grannyknot

Steve, you have the rear vents under the hatch glass on your /71? I found the same problem on my early Z so I had to seal up everything mentioned above as well as the inside hatch vinyl panel as you did. I still have a "shorty" tail pipe and I only smell exhaust on hard down shift or hard braking. TheGrimOne, There certainly is a more than a few aerodynamic flaws on our Z's concerning lift at high speeds as well as turbulence at the rear end that sucks exhaust fumes into the cab. As troublesome as they are I would not change anything about the outward design of my car if it would fix it. The Kammback rear end of Z's is what causes the exhaust to be sucked into the cab, there used to be lots of production cars that used the style, Zeds, Triumph TR6, Opel's, even the Shelby Daytona's. They all suffered from exhaust in the cab. As I remember, the Kammback was suppose to reduce drag, but you sure don't see anymore much anymore. Chris

This is great. Now I can put my original inspection lids back on.

Someone here posted that link a couple of years ago, maybe it was you Mitchell. I printed it off, laminated it and mounted on the wall of my shop, it's just too easy to loose good info like that.

This is the site where Siteunseen's post#8 comes from, lots of info there. Differential Ratios

Zboy, no, they can't "over open" but if your carb butterflies are bottoming out before the gas pedal is then you are stressing it and the linkage which means that metal is wearing and possibly bending. I only bring this up because while our cars are down and we can't use them we have the whole winter to make them perfect, so now would be the time to match the gas pedal stop to the butterfies being fully open. In the situation you describe with your carbs, it won't be the brass butterfies that wear but the aluminum bore they are pushed against as well as the aluminum that the butterfly shaft rides on. That will in time create air leaks and un-metered air will screwup the mixture. In the short term it is not a big deal but matching up the gas pedal stop with the butterflies isn't hard to do. Chris

Outstanding work! Did we pick the same colour?

metalmonkey, I have been watching this thread, I have a 03/70 with the last four numbers 1955. Maybe someday the low VIN will be worth something but not really right now. You got a great deal! You might want to check the archives for Honda wiper motor, it's very simple change over and gives you modern speed wipers. When you get caught in a summer down pour you'll be glad that you didn't stick to original. Chris

Wow, that's jack hammer. Just throwing out ideas, take the tape off the header and see if there is a crack in the pipe. It might be time to pull the head and have a look at things.

I agree completely.

It was either the thicker head gasket or a longer duration cam and since I already had the head off it was a pretty easy to choose. At least now I'll be able use full mechanical advance 35-37* before it would start pinging at 28*

OK, that sounds like you just raised the front of the seat and left the back of the seat low, that would keep the height down and the knees a little higher like modern car seats do. That's a better idea then what I did and that's why it didn't work for me. I have the Integra seats now and really like them but would love to try the s2000 honda seats, don't know how comfy they are but they sure look the part.

I haven't been able to get the engine running for the last few weeks so did some testing and posted a thread in the Electrical section on how I suspected the coil, with the help of SteveJ and Zed I figured out the Pertronix ignition module was fried, apparently these modules don't like to be powered up without the engine running and I had more then a few hours with the power on this winter so I could chase down headlight and fan gremlins. So I thought I would just change over to the new 123Tune distributor I had. I dropped a pencil through the #1 sparkplug hole so I could watch it come up as I turned the crank to TDC (I have done this dozens of times with no problems) but this time the pencil decided to break dropping a 2.5-3" piece of pencil inside the cylinder. Great, and it was the end with the metal sleeve that holds the erazor so I really had to get it out. After about 4-5 hrs of operating through the sparkplug hole I manged to get it out but had broken off the tip of a dental pick while I was doing it. No problem, I inserted my swivel magnetic probe into the hole and started sweeping for the tip, that's when the magnet on the end came off the probe and stuck to the wall of the cylinder, lovely. So now I'm pull the head off to retreave the dental pic tip and the magnet but I still can't bring the piston up to TDC because the magent is stopping the piston. I mark the timing chain and cam sprocket so I can get them back together again and not screw up the timing. I installed the wooden wedge to hold the timing chain and pulled the head off, it doesn't look too bad for 15,000 miles, But while the head was off I started thinking about the engine knock or ping that I have been chasing for the past 2 years. I've done the colder plugs, 94 octane gas, richer mixture but it is still there. So I picked up a Kamarie 1.5mm solid head gasket to bring down the compression to 9.5:1, At $400 I sure hope it is re-useable. After all that the head is back on, engine is running well but will have to wait a bit before I can punch it and see if the ping is gone

I know the 2 aren't related but when there is a crack in the seal of the exhaust manifold or header flange it is easy to hear the exhaust valve slap against the valve seat. #1 and #6 are the first break a stud or have the nut back off. Chris

I'd like to know how you guys delt with that big hump on the bottom of the Miata seat pan that hits the seat mounting bar as you bring the seat forward? Did you just raise the seat enough to clear it? I tried that but found my head hitting the roof.

I received my 123Tune distributor a few weeks ago and with the kind help of Mike W I have programmed it, installed it and the engine is running well. I modified one of Mikes curves to a curve I think is conservative, 8* static at idle up to 29* total advance at 3200 rpm. That will allow me to toodle around town for now and make sure all of the other changes I made to the car this winter are working before I start the final tuning of the carbs and timing. The instructions were translated from Dutch to English so there are a few awkward sentences and some missed steps. The most important being, after you have installed the unit and powered it up you are turning the dizzy clockwise just until the green LED lights up (putting the Hall effect sensor in the perfect spot for TDC), this is where you HAVE to tighten the screw and lock down the unit so it won't move again but there is no mention of that. But now you know or you have figured it out soon enough. Here are few pics, the unit is quite small, smaller even then the original 240Z dizzy but very well made. The only real problem I ran into is my sparkplug wires from DatsunSpirt are measured and cut so that the #1 distributor posistion has to be about at 7-8 o'clock. This is my stock dizzy, This where the 123Tune unit sat at TDC, So after rotating the oil pump driveshaft 90* I ended up with #1 TDC back in the old posistion and all of my wires fit perfectly.

Well, the water is fine here in the deep end, the engine is running well now, thanks guys. Chris

I kinda doubt any god could care less. I understand your desire to rollback the ODO, I have rebuilt a few cars and bikes where the ODO was the only thing on the vehicle that had those kind of miles on it and it bent my nose out of shape knowing that I was not allowed to. BUT at the same time, I wouldn't buy a car that had been rolled back. If there is no historical record you could be buying some hodge podge of thrown together parts. You and I and probably many of the members of this forum could spot that kind of deception but the general public could not. There are many things I would like to change about the great country of Canada, but it hasn't been a nanny state for a very long time. Nanny State is usually a term thrown around by right wing morons that haven't bothered to do their own reshearch and rely on someone elses opinion.

That's a felony charge where I live.

I think the Pertronix module is fried, I tried your test above using a spark plug in the centre wire and there is no spark also, with the Pertronix module hooked up to the coil I only have 11vdc between the coil + and true ground but if I disconnect Pertronix neg wire I get full 13vdc between coil + and true ground. I have this lovely new 123Ignition distributor here ready to be installed so I thought I would get the engine running nicely just like last fall then change over to the new distributor/ignition module and minimize any possible screwups. Well I guess I'll just jump into the deep end and find out what happens. Thanks, Chris

Zed, just did the your test, ignition pwr on, jumper from the neg side of coil tapped quickly against an exposed terminal from the centre post of coil - no spark of any kind. Same test again with the neg jumper coming from the body ground - no spark. There is 9vdc there, how can no spark happen?

If I were start over I would buy everything possible at rockauto because of their prices, then Z car source and MSA would be last on my list.

Zed, running Pertronix ignition. Steve, using the 200ohm scale resistance between pos and neg is 3.3 ohms, Using the 20K ohm scale resistance between the centre post and neg is 9.4, With the power on I get 9vdc between pos and neg and 8.8vdc between the centre post and neg.

Yeah, that really shows. My comment in post#3 is mostly how I feel about rattle can paint jobs. I see so many of them at car shows, just makes me shake my head.

High side and low side? Pos and neg I understand, are you refering to the centre post terminal of the coil?

Have been trying to get the Z started the last few weeks with no luck. It was running like a top last fall before I put it to bed, the only things I've changed over the winter that might effect the ignition system is that a 140 amp alternator was swapped in and new MSD plug wires - DSI Spark Plug Wires | | Datsun Spirit, Inc. were added. I have checked and rechecked all the usual suspects then I set up my remote starter so I could crank the engine and watch the actual spark from the plugs as they are pulled and grounded against the head. The first 2 sparks are big and fat, after that they peter off to a very tiny spark as I continue to crank. That sounds like the coil to me, but it only has 4 months use on it from new! It's a Pertronx Flamethrower 3ohm. Battery is fully charged, gas tank was topped up in Oct. and stabilizer added, 4month old plugs were pulled and soda blasted to clean them up, air filters have been removed for start up. Thanks, Chris