Mark Maras

A good rad. shop can re-core it. I've always used Mac's in Portland but there must be a good shop in Bend or Redmond. Here's my tip. Pick up a mechanics pad at Harbor Freight. It's a trifold cushion about 5' long that makes everything much less painful. It also works great for under dash work if you remove the seat.

Take a look at the front carb.The likely culprits for the first three sooty plugs are; sticking fuel nozzle, misadjusted choke cable, mixture screw adj. or float level.

It sounds like valve train to me. I'd pull the valve cover, start it up and use the prev. mentioned hose to find the source of the sound. I've used the hose for years. AmaZing tool. Works well for checking the carb. balance too.

There is one more vac. line from the base of the front carb to the vac. diaphram on the dizzy.

The hoses into the back of the air filter aren't vacuum lines. They all vent fumes from the float bowls and the engine to be burned. Vacuum lines are usually found coming from the base of a carb or the intake manifold.

It sounds like valve train noise to me, I'd pull the valve cover & see if the oil tube is squirting, drooling or leaking. It should be squirting oil out uf 12 holes in the tube. The lower compression on #s 2 & 4 would have me rechecking the valve adj on those two.

The tic tic sounds lindicate the plugs are firing. I'd pull #2 or 3 plug & ground it to actually see what, if anything, is going on. Compression? Recheck the valve adj. & compression to eliminate that possibility. That leaves FI. I'm an SU guy but basic injector function must be easy an easy test. I'd guess disconnecting the injectors one at a time.

Check the inside of the dizzy cap boots & the spark plug boots to see if the connectors have pulled back. If this is a consistant no fire in two cyls. it is isolated to the wires, cap, rotor or plugs all of which are new. Swap #1 & #2 plug wires & see if the miss changes to #1. This problem is usually a poor elec. connection, especially when you have new components.

Assuming you've done a recent complete tune up, the front carb sounds like the problem. Check the following; fuel nozzle sticking in the down position when the choke is off. cable adjusted to allow nozzle to return, float level ( you'll need a new gasket), compare piston drop in both carbs(oil cap in & out), everything OK then turn the mixture screw clockwise 1/2 turn, this will lean the mixture in that carb. clean the plugs & drive it. Check back.

The ratcheting, You can hear it, can you feel it as well? What part of the car is it coming from? Can you feel it in the shifter, the body, the seat or the pedals? Also, have you noticed any changes in the car previous to this noise? Any info you can share, no matter how trivial, will be a big help.

A couple of questions. Are all the windows up when this happens? Can you change the noise using windows or vents? The reason I ask is my Camry thuds my eardrums above 60 mph with the left rear window down. Yeah, left only.?? This may be the same noise as the Audi prev. mentioned. My answer is as simple as rolling up a window. Is it possible you have air leakage into or out of the cabin that could be causing it?

Point Float. Racers back in the 50s & 60s would cut a small piece of neoprene rubber & wedge it behind the movable point. This was a common way to eliminate point float from the list of things that could go wrong, or at least it did no harm & made them feel better. The neoprene usually came from a wet suit back then.

Nice find and welcome to the club. The members here are eager to share their knowledge with others. Check out the forums on whatever Z topic you wish. You'll find hours worth of reading there.

OK, I haven't researched them, just repeating what the PO told me. I obviously have some homework to do, If they're not DGV's, what are they. Anyone recognize them? They came as extra parts with my 74 & are set up for a Z.

Here are the pics of the DVGs The PO said 1 carb has a bad diaphram. Unfortunately he didn't remember which carb it was. I assume it's probably an accelerator pump diaphram, but that's just a guess on my part. I don't have plans for them at this time, Maybe way in the future but I have plenty to work on before I start swapping carbs out of boredom.

I'll post a pic of my DVGs tonight when I get home from work.

Having experienced clutch seizure, The noise is a lot like small plane prop. & HP drops about 25%. I drove my Z with a flex fan (no clutch) over 100k miles and had no complaints. Mine has a 2" spacer which sets the fan 1" from the radiator instead of 1 5/8". Fan diam. is 15" & acually gets quieter at higher RPMs. If you watch it as you rev the engine the blades flatten out. The individual blades are quite large 3 1/2" x 5 1/4". At the time I thought I would add a shroud but didn't need it after all. My orig. fan had steel blades & weighed a lot. with the FF, the engine reved noticeably quicker. TomoHawk, I don't ever remember my fan clutch, for the few years that it lasted, cycling as you described. Confession, I drove the car daily without a fan in the summer time for 2 weeks. This is what I learned. RPMs are heat. Duh! Keep the revs low and shut it off instead of idling. I found that at 10 MPH or above I could keep the car at the normal temp. this way. I came to realize that it doesn't take much speed at all to make a fan useless. i wasn't entirely sure if the FF would solve my overheating at idle but i was totally satisfied.

Being an old timer :-) Everything you've been told is correct. You can get as deep into advance curve theory as you desire but if you just want to have a good running car, retard the timing until it won't ping at anytime or perhaps barely when lugging the engine ridiculously low. It doesn't take many pings to break a piston ring in an old engine. (Hi-Lux PU, rarely pinged). I think you may want to put away the timing light. If you time it by ear you'll know it's right.

I believe it's time to break out the 3' garden hose stethescope. You'll be able to listen down in the tunnel & find out if the noise is coming from the outside before removing your console. I'm still unsure if the noise changes with the clutch pedal in.

Just checked PicNPul here in Portland. There is a 76 in SE P. & a 77 in Sherwood. I don't know if it's worth the drive. I'd be glad to drop by the SE P. one & see if the ex. manifold is still on it. I can also check Sherwood if SE P. doesn't have one.

Go for it. I can understand your desire for a trouble free DD. I drove my 71 daily for 23 years with SUs and it was the most reliable car I ever owned but I did take care of the carbs with regular maintenance. It was all new and fun back then. The Holley will give you everything you want without the tinkering. I've never seen the air filter arrangement for this mod, there can't be much room between the carb and the hood.

I would definitely tell the fuel station owner of problem you've encountered. He needs to know, for all the obvious reasons. As far as what to do next.? I think the 4 litres of methanol and dropping the tank, from your list above, are probably over kill. Everything else on your list sounds good as well as adding some methanol to your first tankful of gas.

Retirement, a fresh Z and summer on the way. Life can truly be good.

Fan measurements, The 2 stock fans that came with my project 74 both measure 16" + or - a 1/16th. they are identical to each other except 1 is steel & 1 is plastic. Fan to rad meas, is 1 5/8". 71 Z is still around & has a 5 bladed flex fan on it. Fan diam. is 15". Alum. spacer is 2". Fan to rad meas. is 1". Individual blade meas, is 3 1/2" x 5 1/4". It is going on the 74 soon. We'll see what the future holds.Mark in Portland

I didn't experience any noise and the cooling was great. I suspect a lot of the negative opinions are not from experience. As I said before, I had NO problems and would install another one in a heartbeat. Mine was great. I'll measure my stock fan and get you some more info on it when I get home tonight. Mark in Portland