Help! Engine won't start! Already tried some stuff

[bippu z]

The guys over @ HybridZ wouldn't help me...

I recently bought a late model '74 260Z. It's the coupe model too. Uhm, the kid I bought it from said that it only needed a new battery and the fluids replaced. Did that first night and tried to start it. Nothing happened. It turns over great though. Through various sources I've gotten instructions to check the fuses, replace the rear electric fuel pump, replace fuel hoses, check the mechanical pump up front, replace the 10yo gas (did that first night too) and get a manual. Done all that stuff. The manual I have, said that the elec. pump doesn't start until 400rpm. The mech. pump looks to have too much play in the lever, but the offset cam lobe makes up for it, so it works. It's not clogged, and both new and old elec. pumps work.

I also sprayed starter fluid in the intake and put a little gas into the swapped 240Z carbs. Buddy o mine from wyotech put propane right into the cylinders.

Any other pointers other than replacing the fuel system? Cuz all it's done is backfire...

[ktm]

Have you checked your timing? Pull the valve cover and rotate the engine until the cam lobes for #1 cylinder are making rabbit ears. Pull the distributor cover and make sure that the rotor is pointing to the number #1 plug. Look at the timing indictor on the crank pulley and make sure that it is showing TDC as well.

Hybridz is for the advanced Z enthusiast. They expect that you already know how to do the basics. As they like to say, the site is geared for high performance modifications to the Z-series.

This site is full of knowledgeable people (Arne, Zs-ondabrain, Sblake, Tony D, jmortensen, johnc), some of who also post on Hybridz and Zcar.com.

[JimmyZ]

In your desciption above I didnt see much mention of ignition troubleshooting. I'm assuming you have spark and that the plugs are all clean??

[e_racer1999]

have you pulled the fuel lines to make sure that you're actually getting gas to the carbs? also, try putting a little oil in your cylinders. you might have washed your cylinder walls and may not be getting compression.

[Walter Moore]

... replace the 10yo gas...

That right there is a hint. It hasn't been running in a long time. Check the compression on all six cylinders. It is likely that the rings are stuck.

I am sure someone knows how to deal with that short of rebuilding the engine, but that is what I ended up doing to my 240.

More suggestions guys? If his rings are stuck and he is getting no compression what can be done?

[Nissanman]

Pull all the plugs out and crank it over.

Plug each spark plug hole in turn with a finger of your choice and it should fart nice and strong when the piston comes up on the compression stroke.

Check all of the cylinders for equality as best as you can determine.

If compression is weak, then things go a little pear shaped.

A squirt of WD-40 into each spark plug hole would help free up any stuck bits.

May take a few doses and a few days though.

You may also have stuck valves in their guides.

To free them up you can tap onto the top of the rockers with a little hammer to loosen up the stems.

Won't hurt to dose them up with some WD-40 either.

When you are happy that the engine can compress OK, you will need to check the spark etc. as mentioned.

If this sucker hasn't been running for 10 years, it may need quite a lot of coaxing:nervous::nervous:

[bippu z]

Kinda a mass reply here...

I've replaced the spark plugs. What was in there was NGK Platinums. I just got the generic equivalent from Champion. It's supposed to be just a tiny bit cooler. Um.. Spark is there, but weak. I put 91 Octane in it though. And my WyoTech friend says that compression is good. If i remember right, it was 60psi in each cylinder? Does that sound about right? I dont have my manual with me...

I'll try putting some WD in the cylinders tommorow after work.

Something I haven't done is check the hard fuel lines. I've replaced most hoses, but I'm no mechanic, so I haven't touched the internals. I know a guy who can hook up some fancy gizmos to it. Problem is I gotta tow it to his shop... so I'm trying to get as much of it done by myself.

Do you think vaccum might be a problem?

[Nissanman]

If it is 60psi per cylinder, Houston, you have a problem:rolleyes:

Needs to be in the order of 180psi non-turbo and 140psi for a turbo engine.

If everything else is OK, fuel in the float bowls should be enough to get it going.

You won't be developing much vacuum until it actually fires up so that in itself is a non-event.

If spark is not adequate, it will not fire up, so we need to look at that too.

[bippu z]

i would hope spark is good.. i just replaced the plugs. but i guess i could order a new rotor and plug wires to be safe.

i was just wondering about vacuum because i was looking at the engine a few days ago and i noticed that there were a few holes in the motor and some vacuum hoses disconnected. i dont know what went where either.. it just came that way. advice on that note?

[Fun_in_my_z]

If there is no spark going to the new plugs then what good are they? I would change the wires and check the distributor and the coil.

[holtyrd]

I have had a problem like this on my Z. There are three connections that, if not connected, the car will not start but will turn over. One is one the starter, it will be the little wire on the positive terminal. Another is the Tach connection to the positive side of the coil. The last one is the ground wire to the distributer. I'm saying this is what the problem is but it could be an easy fix.

[Nissanman]

I see what you mean about vacuum now.

Those open ports will be an issue when you try to drive the car, they will suck air and **** up the fuel mixture.

However, at this stage, you could just plug all the manifold nipples with a short length hose with the end clamped off, that should be OK for the short term.

We can sort out the final configuration of those later on.

What are the actual compression readings 60psi or what??