Still struggling with car at idle after 8 years

[jalexquijano]

17 hours ago, Yarb said:

Time to pull that head off where you can see what is going on IMHO.

This is sure a lot of work man! Damn those guys in californa datsun!

 

[emccallum]

It isn't too bad of a job. When I was young we used to a few pieces of heater hoses to hold the chain in place! Take your time and dont forget the two front bolts on the head. I hope you find something wrong 🙂 

[jalexquijano]

I also hope. Someone here mentioned something about the dizzy. I dont think there is any problem there.

[Patcon]

1 hour ago, jalexquijano said:

I also hope. Someone here mentioned something about the dizzy. I dont think there is any problem there.

Replacing the dizzy and pertronix is easier than building an engine

[jalexquijano]

22 minutes ago, Patcon said:

Replacing the dizzy and pertronix is easier than building an engine

What leads you to think the dizzy and pertronix is damaged?

[Patcon]

You've done valve seals and touched almost every other external aspect of this engine. If it were mine, I would replace the dizzy, plug wires and coil. If that doesn't fix the issue then it pretty much has to be internal to the engine

[dutchzcarguy]

3 hours ago, Patcon said:

If it were mine, I would replace the dizzy, plug wires and coil.

I haven't read the whole story but i guess when you reach 30 !!! pages you have done every aspect..  IF NOT.. do get yourself a new distributor and coil and stuff..  I drive a datsun 240z now for 24 years and always have a lot of spareparts hanging/laying/standing around.. i can't understand why people sell every part they have laying around when they have restored a car. I drive it summer and winter (300zxtt in the summer only also) and it's VERY HANDY to have your own partsstore!  I once bought a spare engine complete and took a car completely apart for parts as the bodywork was to far gone.

Always handy to have some extra parts as you can barter/exchange.. and your stuff keeps it's value.. once bought a good gearbox for 75 euro.. now it's 1500 euro.. 🙈
 

What people also do is exchange parts from another car and see if the problem moves to the other car.. but i guess you can't or already done that.. (I mean asked this..) 

Btw, i admire your patience, I would have stuck that car behind the wallpaper ages ago!!  (It's a Dutch saying translated! hahaha.. ) 🤣🤣🤣

[gundee]

Plug wires are likely fine. Under load is when they can break down.

His issue is at idle. Under load he says the plug cleans itself up.

Hopefully the issue is in the head and not the bottom end. Would be nice if it were just an oil seal.

[jalexquijano]

26 minutes ago, gundee said:

Plug wires are likely fine. Under load is when they can break down.

His issue is at idle. Under load he says the plug cleans itself up.

Hopefully the issue is in the head and not the bottom end. Would be nice if it were just an oil seal.

The thing is that both of the seals in that 4th cylinder were replaced last year. I posted pictures previously.  This is what California Datsun installed inside of that engine. I just want to have the parts ready to be installed once the machine shop in panama rectifies the head. Any quality gasket kit and parts to he considered?

[jalexquijano]

4 hours ago, gundee said:

Plug wires are likely fine. Under load is when they can break down.

His issue is at idle. Under load he says the plug cleans itself up.

Hopefully the issue is in the head and not the bottom end. Would be nice if it were just an oil seal.

Gundee and others,

Here is a pic of the valve intake and exhaust seal change process done in 2021. Plug keeps coming out black and this is always after traffic jams at idle.

[jalexquijano]

On 3/17/2024 at 6:55 PM, Mark Maras said:

How long does it idle before fouling a plug? Assuming (correct me if I'm wrong) it starts to run on seven cylinders, will the plug clean up if you run the engine at high revs (Italian tune-up) for a while?

Car has a new set of plugs right now. We can do a new and final test and let the car idling fo 15 minutes simulating a traffic jam. Nevertheless, we do know that plug will get fouled anyway. Do you think i should invest in a brand single point new distributor and coil before opening the head? 

[emccallum]

I would eliminate everything I could before pulling the head, especially since you have good compression, no smoking and no signs of a bad head gasket. You may want to remove the rotor in the dizzy and check the dizzy shaft for play. It should have no play. If it has play that can cause inconsistent firing. I dont know if it could cause a single cylinder to always missfire or how a pertronix would be affected. I do recall you getting better running when you were messing with the ignition wiring. Maybe swap a plug wire just to be sure it isnt one of the wires.

 

Edited April 2 by emccallum