David F

I purchased my '71 Z about 5 years ago (car found via Bring-a-Trailer ad link), fixed it up cosmetically (mostly interior), rebuilt the suspension, and got the engine running very well. I enjoyed the car as a winter daily driver (no a/c in Texas) for many years and decided it was time to move on. I really enjoyed this forum, especially the helpful members. I hope I contributed some as well. I purchased the Z for about $6900, put about $7k into it and sold it for $19k. I think I and the buyer came out ok. Before you think I undersold, the car was definitely not perfect. So, this description might give you an idea of why the selling/purchase price: Engine: not number matching, 2.6L Trans: Not original automatic. I swapped in a five speed from early ZX Body: respray was off shade. Roof sheetmetal is wavy. several small dings. Hood/nose had been hit in past and repaired with lots of body filler. hood drooped at nose (emblem recess filled in, no emblem). I restored the black interior, original dash with NO CRACKS. Interior look great! Engine purrs, lots of power, no oil leaks or consumption. Anyway, car leaves my possession on Saturday...will be a sad day. And, I will miss this forum...take care all. Replacement project is an '82 BMW E21 320i Sport (Hennarot). I am using this car to learn how to do my own upholstery work.

I do not understand the comments about the throw out bearing being the cause of the noise. When the clutch is out (i.e. not depressed) there is no load on the TO bearing. When you depress the clutch, the TO bearing comes into play. So, saying the TO bearing is making the noise in neutral makes no sense to me. My TO bearing is brand new and noise there from day one. Seems like transmission bearing noise to me.

My 72 with 79 280Z five speed makes the same noise. Clutch out, noise. Depress clutch, noise gone. All new clutch components. As others have said, my assumption is that it is not the throwout bearing as there is no load on the bearing when the clutch is out and the noise is present. If I depress the clutch slightly, the noise stops. So, I guess it could be throwout bearing slop/end play at work. But, the noise certainly sounds like bearing noise which I assume was the input shaft. I'm living with it....

I just stumbled upon this thread. Two of my favorite cars: Z's and M's. Good work.

I will expand on my earlier 3 word reply. I had the same issues. Tried two new pumps only to have them fail or pump insufficiently almost immediately. So, I installed an electric pump and left the mechanical pump in place. The electric pump is controlled electronically which means it needs a tach signal to stay pumping after a 3 second prime period when power is applied (i.e. key on). The electric pump solved the empty fuel filter issues and cold starts after prolonged period of non-use was great. But, problems soon became evident. After the engine reached operating temps and got a little warm due to idling in traffic, the engine tended to flood due to fuel overwhelming the carb float valves. So, my current solution was to disconnect the tach lead from the electric pump controller. This prevents the pump from running while the engine running; thereby, relying on the mechanical pump. But, the electric pumps still runs for 3 seconds when the key is placed in the one position; thereby, priming the carb fuel bowls. When the engine is warm to hot, it will stumble slightly on hard acceleration due to inadequate fuel from the marginal mechanical pump. I cannot seem to get the fuel delivery just right. But, an occasional stumble is better than flooding, so living with it for now.

Weak fuel pump.

I did a hybrid of above. I cut the tubes, pinched them closed and welded the pinch together.

The pump eccentric is fine. As I mentioned, when I pull the non working pumps, they don’t pump when operated by hand.

One was a Delphi MF0139 from Rock Auto. The other was a Spectra Premium from Autozone A1203MP (this pump was identical to the Delphi regardless of what a Google search indicates). Both pumps were similar in appearance to original (i.e. screw top). Both initially worked fine for about 15 minutes...then stopped pumping. Pulled pump operated arm, nothing to very little suction.

That's it, the flow guide valve. It is not connected to the crankcase, so it is simply venting to atmosphere. It is connected to the tank vent line and air filter box. I recall cleaning it up a few years ago, maybe it is stuck again. So, have purchased two replacement mechanical pumps and neither worked longer than 30 minutes out of the box. So, I kept the marginal working one and added the electric. So, what is the best mechanical pump to purchase and from whom?

When I purchased the car and went through it get it running, I cleaned the carb heat thermostat and got it working. Since then, I have completely forgotten about it. Incidentally, it is usually the rear carb that acts up. I will look into bypassing the carb heat and see if things are improved. Yesterday, I pulled the tach signal from my electric pump controller (this way, it still primes on key on, but does not run while engine is running) and relied on my mechanical pump. I drove the car 200 miles without the flooding issue. But, I was not struck in traffic. Outside temp was 80 degrees. I was reminded that the engine misses under heavy acceleration when running on mechanical pump only. When electric pump is on, no missing. So, it seems I need something in between.

I did just that, the fuel is expanding to the point it is at the top of the filler neck and escaping past the cap.

Heat shield in place, float level set via 12 turn down method, plugs are good color, and runs fabulously when not trying to flood out. Problem seems to occur when temp creeps above half-way on gauge

'72 240. Been having a periodic problem of flooding while at idle. Symptom is fuel bowl overflowing usually while sitting in traffic or after returning from short engine off period. My initial thought was that my 3psi electric pump was overloading the needle valves. But, this does not explain why it runs fine normally. So, this past weekend, I filled the tank (probably more full than usual and after the car sat in the sun for a few hours I smelled fuel and noticed fuel spilling out from the filler (with cap in place). So, I disconnect the vapor valve under the hood and blew through the vent line back to the tank...it was free flowing. So, my theory is hot fuel create vapor pressure that is overwhelming the carb needle valve during idling (low fuel demand). I am in the process of testing my theory by disconnecting the vent line from the valve (i.e. tank open to atmosphere). Main question is do you think I am on the right track and second, how is that valve suppose to work (can it be tested)?

What do you mean "bend the arm" for testing. Do you mean simply move the arm up and down? My gauge responds similarly as it reads empty with just less than half tank remaining. To me, it will be an easy fix by actually bending the float arm down so the gauge thinks there is more fuel in the tank.