240z electronic ignition help

[vantage]

Difficult to say, i am not too familiar with the cam and valves of the L24. Which one is the intake and which one the exhaust valve? If the right one next to the chains is the exhaust valve then cyl #1 would be at the end of the power/burn phase (e.g. too late). If the left one is the exhaust valve, then cyl #1 would be shortly before the intake phase (e.g. too early).

 

In both cases it would not look be correcnt, the cyl #1 should be after the compression phase, e.g. both valves are closed. It might be helpful if you watch the cam openening/closing the valves while standing in front of the engine and slowly turning the crankshaft manually to see which cylinder is in the correct compression/burn phase while the balancer mark hits the degree marker.

[Mikez31ss]

I'll check that and get some pics after one more crank revolution.

 

The L24 is the same as the other s30/130 engines regarding valves. Here are some better pics and one with the valves marked:

 

 

 

And a larger pic:

 

[Tony D]

#1 Compression stroke is easy to verify: remove the plugs, bump the starter with your finger over #1 spark plug hole, when it blows, you're starting compression stroke. Manually advance it to TDC and start from there.

 

Your previous (most recent) photos show the position of #1 while #6 is on the compression stroke (180 out).

 

Likely, distributor out 180, rotor should be the 'other way' at that point of cam rotation.

 

Cam will 'Rabbit Ears' on #1 when in compression stroke, one valve will point up to the left of the car, the other up to the right.

 

Finger test and you will never be wrong. Observe distributor rotation, and apply wires appropriately 153624 and it will be in the correct firing order, regardless of where the rotor points. Just start at #1, and minding rotation install wires accordingly.

[Mikez31ss]

I disassembled the dizzy far enough to rotate the upper shaft around and then turned the crank to line up at 0 degrees again. This is as rabbit eared as it gets. I'm going to try to get this thing cranked up tomorrow and set the timing and then get busy with the carb seals and gaskets. Even with the mechanical pump and fuel pressure dead on 3psi... I'm still getting gas coming out the carbs.

 

 

 

 

[vantage]

Tony, thanks for tuning in!

 

Mike, looks good on the latest photo Hmm, 3.0 psi are fine for the DCOE's. Have asked my Weber guy and he told me to check the float level and function, and to check and clean the needle valve. Not very likely if you have exactly the same issue on two carbs though but probably still worth a try. Take care you dont start a fire in the engine compartment.

[Mikez31ss]

Tony, thanks for tuning in!

 

Mike, looks good on the latest photo Hmm, 3.0 psi are fine for the DCOE's. Have asked my Weber guy and he told me to check the float level and function, and to check and clean the needle valve. Not very likely if you have exactly the same issue on two carbs though but probably still worth a try. Take care you dont start a fire in the engine compartment.

Yeah I want to thank Tony as well. Always good to have the master check things out

The Webers have leaked since long before I got the car. I bought the comprehensive service kits from eurocarbs and I need to get to that as soon as possible. I did want to get the car running again and timed just to be sure any issues that come up after I work on the carbs is carb related and not ignition or timing.

I'm a little leery of doing the carbs. Mainly because I have no clue where half the parts go. There aren't a lot of parts compared to say a Holley or Rochester 4v, just some seals, gaskets, o-rings, needle valves, and mixture screws...but being a novice I'd rather not disassemble anything I don't need to. I've looked around the web and emailed Matt at eurocarbs but there isn't a service kit "how-to" available. If the parts were labeled I could find them on the diagram. Some of the parts look a lot alike. I have a Weber manual so I'll see if I can figure it out.

I'll post what happens when I try to start the engine tomorrow.

I'll try not to start any fires

[vantage]

Where does the DCOE's leak?

 

Might be a quick and easy start to remove the top cover and check out the following items before doing the next engine start:

 

- The floats (#9) do work (are not stuck or sticky) and are not punctured and filled with gas

- The needle valve (#8) is clean and functional (if your service kit contains new needle valves then just replace them)

 

http://www.webercarbsdirect.com/v/vspfiles/weber_carburetor_schematics/45DCOE152.pdf

[Mikez31ss]

Where does the DCOE's leak?

 

Might be a quick and easy start to remove the top cover and check out the following items before doing the next engine start:

 

- The floats (#9) do work (are not stuck or sticky) and are not punctured and filled with gas

- The needle valve (#8) is clean and functional (if your service kit contains new needle valves then just replace them)

 

http://www.webercarbsdirect.com/v/vspfiles/weber_carburetor_schematics/45DCOE152.pdf

The carbs leak out the front. The kit does indeed have new needle valves. I'm going to look at the DCOE parts diagram and my Weber manual and try to figure out where all the parts in the kits go.

Today is the first time I've tried to start it since my last post. It was trying really hard to start. A couple of times it caught for a few seconds but I didn't give it throttle and I think I should have. Then a neighbor came over and turned the dizzy all the way CW (advanced?) and it wouldn't even try to start. I'm pretty sure the battery is going bad. The starter was turning much slower. The neighbor left and came back with a spark tester. He says it has weak orange spark. I'm hoping that is from the low battery.

Later...I had the battery charged at Autozone. When I went to pick it up they tested it and the machine read "battery good...low charge." The counterguy said that means it's going bad but maybe they just didn't leave it on the charger long enough. He was swamped with customers and had just one inexperienced helper so who knows. Maybe the battery has enough juice left to get the car started. I also had a battery in the garage that I bought new two years ago and never used. I dropped that one off to be charged when I picked the other one up.

BTW, before I tried to start the engine I turned the crank so that the balancer mark was closer to 10 than 5 and then turned the dizzy so that the rotor was facing the #1 point on the reluctor. I hope that was right.

[vantage]

The carbs leak out the front. The kit does indeed have new needle valves. I'm going to look at the DCOE parts diagram and my Weber manual and try to figure out where all the parts in the kits go.

Today is the first time I've tried to start it since my last post. It was trying really hard to start. A couple of times it caught for a few seconds but I didn't give it throttle and I think I should have. Then a neighbor came over and turned the dizzy all the way CW (advanced?) and it wouldn't even try to start. I'm pretty sure the battery is going bad. The starter was turning much slower. The neighbor left and came back with a spark tester. He says it has weak orange spark. I'm hoping that is from the low battery.

Later...I had the battery charged at Autozone. When I went to pick it up they tested it and the machine read "battery good...low charge." The counterguy said that means it's going bad but maybe they just didn't leave it on the charger long enough. He was swamped with customers and had just one inexperienced helper so who knows. Maybe the battery has enough juice left to get the car started. I also had a battery in the garage that I bought new two years ago and never used. I dropped that one off to be charged when I picked the other one up.

BTW, before I tried to start the engine I turned the crank so that the balancer mark was closer to 10 than 5 and then turned the dizzy so that the rotor was facing the #1 point on the reluctor. I hope that was right.

 

A fresh or fully charged battery would be good, you want to have a strong spark and quick starter. With a mechanical fuel pump you need some rotations of the engine to prime the carbs, then when starting press the throttle a bit and keep it there. As the car was standing for so long, i would recommend to remove the air box and apply a bit of starter spray or brake cleaner into both carb intakes and try starting again. Make sure that the plugs are not wet from previous starting test.

 

good luck,

Adrian

[Mikez31ss]

A fresh or fully charged battery would be good, you want to have a strong spark and quick starter. With a mechanical fuel pump you need some rotations of the engine to prime the carbs, then when starting press the throttle a bit and keep it there. As the car was standing for so long, i would recommend to remove the air box and apply a bit of starter spray or brake cleaner into both carb intakes and try starting again. Make sure that the plugs are not wet from previous starting test.

 

good luck,

Adrian

Thanks Adrian. BTW I have 3 carbs

There is a "starter circuit" in the carbs but there is no cable to activate it. I'm not even sure how much it would help.

Any updates on your car?

[vantage]

sorry, i meant apply into both intakes of each carb The starter feature ist not available in all DCOEs, it depends if you actually have the starter valve in the carbs installed by the factory, so dont worry about that.

[Mikez31ss]

Ok...it's running!

I'll be back later with some questions on something though

 

later it is

Alright...like I said it runs now

The guy across the street came over to hear it running. He is a semi-retired mechanic. He said it sounds like the dizzy is one tooth off. I don't know if I buy that. The car has a performance cam, it hasn't ran in months, and it wasn't warmed up good. And the carbs may need to be synced. I think that is what he heard. Before I did the swap I took the car in for a safety inspection. On the drive home I revved the engine and dropped the clutch and it smoked the tires. I don't think the car would have that much power if the oil pump shaft wasn't lined up causing the timing to be off, would it? Not that the car is seriously powerful anyway lol.

I wouldn't know how to check if it is off without removing the oil pump. That seems like a lot of work just on the basis of someone's opinion given the circumstances. Any thoughts on that?

Also a couple of times when I drove before the dizzy swap I thought I saw a wisp of smoke near the left headlight. I tried to figure out what it was but I couldn't get it to happen when I tried. I couldn't think of anything there that would smoke so I decided it was overactive imagination. Today when it started I noticed a little smoke and it was steady so I was able to see that it was coming from a braided hose coming off the motor. The other end of the hose is open to atmosphere. We decided that it's blowby. The neighbor thinks the piston rings are probably sticking from the car sitting for so long. He thinks that if I take the car out and run it that the rings will reseat and seal normally. I think he may be right. I hope so. Was that hose connected to something in factory configuration? I'll post a couple of pics at the bottom.

Now I need to set the timing. I think around 8-10 degrees? I'll go back and check. I guess it's time to do the carbs after that. I may make another thread with pics of the parts in the kit and pics of the carbs and see if anybody will ID the parts and give some pointers on installing them so I don't open anything up that doesn't need to be opened up.

After that I need to figure out why the tach doesn't work. I would guess it won't work without getting signal from the negative side of the coil?

Edited July 13, 2010 by Mikez31ss

[vantage]

Congrats, well done!

 

Distributor "one tooth off", that would have the same effect as being not properly set to the correct static timing. Your engine needs to settle in and the timing is not set yet, so no worries here.

 

Timing, 10º should be good. Let the engine warm up (stay below 2-2.5K), then set the timing to 10º using the strobe light. Do a test drive and also check if the engine pings on load but you should be good with that setting. Should be no problem to go up to 15º static advance with out the vacuum connected (i assume that you ignore the vacuum advance with your weber setup). Max advance should be 36º-38º at 2000-3000 RPM, you could check that with a variable timing light if you can borrow one.

 

I cant make out where the tube comes from in the photo but crankcase blowby sounds quite likely, the smoke should vanish after some hours of (gentle) driving when the engine has settled in again after the long rest.

 

 

Regarding the tach, you have a four wire tach where one side of the coil runs through a small loop at the back of the tach. So...

 

• 
   
  
• When you remove the four pin connector from the tach, does the car still start? (It shouldnt) Then we need to take a look at the wiring.
  
• If the car does not start with the connector removed, the wiring appears to be correct. Then remove the tach and check out the white wire loop. It runs through a white piece of plastic which is fixed by a small metal clamp. Make sure that the small metal clamp is not bend and connects to the small metal counterpart on each side.
  
• While you at it, also make sure that you can measure +12V between the black and red/yellow wire at the back of the tach while connected to the car wiring and with the ignition on
  

Edited July 13, 2010 by vantage

[Mikez31ss]

Check it out Adrian

 

[Leon]

That hose looks like the one for the positive crankcase ventilation (PCV) system. It should be plugged into the PCV valve. I see that your running triples and don't have a PCV valve so you can route the hose into a catch-can. Not the best solution but it should work.

Edited July 16, 2010 by Leon

[Mikez31ss]

That hose looks like the one for the positive crankcase ventilation (PCV) system. It should be plugged into the PCV valve. I see that your running triples and don't have a PCV valve so you can route the hose into a catch-can. Not the best solution but it should work.

I think you're right Leon. I first thought it went to the air pump which was removed long ago.

What would be a good solution? Route it into the intake somehow?

[Leon]

I have triples as well that I will be installing and I was thinking of using the hole in the intake that's provisioned for the vacuum advance for the PCV instead. I don't know how many vacuum provisions you have in your intake, but I have one for the brake booster and one for vacuum advance. I won't be using the vac advance (I'm using the ZX dizzy for my 240Z as well) so I figured that tap is good for something. I'll have to check the threading of the PCV valve and see if I can screw it into the manifold. If not, it can probably be connected in between two lines with one routed to the block and the other to the intake manifold.

 

Like I said, the catch can is your other solution.

[Mikez31ss]

Adrian...the timing was at 20degrees. Now it's a shade under 10. No pinging. Matter of fact it seems way rich. It seems good other than the hellacious lope and a little smoke. The vac advance is capped.

My car will start with the white connector unplugged. Bad news I guess. There is 11v between the black and the red/yellow. I never get 12v at any connection. Maybe my meter is off.

The white wire loop looks great. No corrosion or bent parts. I can't see anything wrong with it.

 

Leon...I've only got the brake booster port. When I remove the carbs I could probably drill a port in the manifold. Looks like a boss is there on #2. Is it a good idea to run that hose into just one cylinder? I guess if the blowby clears up it wouldn't make much difference.

 

I have a catch can left over from my 300zx cars but it's a pretty janky part.

[vantage]

My car will start with the white connector unplugged. Bad news I guess. There is 11v between the black and the red/yellow. I never get 12v at any connection. Maybe my meter is off.

The white wire loop looks great. No corrosion or bent parts. I can't see anything wrong with it.

I think this is good news as your tach might still be functional Voltage between black and red/yellow is good, so your tach receives power!

 

• Measure the green/white wire on the connector to which the tach is connected and ground, do you see ~12V?
  
• Please check which wire color is connected to the Ignition coil (+) terminal (should be black/white)
  
• Also, is there an disconnected black/white or green/white wire next to the coil/ballast somewhere?
   
  

Regarding your meter, do you get 12,5V when you measure the battery while the engine is idling?

[Mikez31ss]

Hey Adrian...how are you doing? Hard to believe this thread is so old

 

I found three wires in the harness cut and taped up near the coil.

Green... for the noise suppression capacitor?

Green & white...must have been for the ballast resistor.

Black & yellow... Has 12 volts with the key in "run". With the key off it has continuity with the green & white wire.

 

A shorter black & white wire w/ a female connector was hanging loose. No power.

A longer black & wire wire was connected to the coil positive. 12 volts.

A black wire was connected to the coil negative.

 

One thing that I'm curious about is the way the coil was wired when I got the car.

There was no ballast resistor so the resistor wasn't shorted obviously but the wires that should have been connected to the resistor weren't connected together.

And the coil was a "use with ballast resistor" type.

I'll check the green/white wire on the connecter later.

 

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