engine won't crank

[240Zdragon72]

I have just aquired a '72 240Z with a 280Z L28 engine. Here is where it gets tricky.... new sparkplug wires, coil, and Optima battery. Still not cranking. It all started with me and my wife trying to jump the old battery. We got a quarter of a crank but that was it. Then the next step was to put the new battery in. NOW from the ignition, I don't even get a crank. I can hear the (I guess) starter relay clicking but nothing to the starter. Took the starter off, works as advertised. Put the starter back on, still nothing. Then back to the starter....I put the jumper cables on my other car and took the - and mounted it right to the - on the starter. Then taking the + side of the jumper cables and touching the + side of the starter, I'm getting the same quarter of a turn and no juice. On the instrument panel, all the bells and lights work. BUT NO JUICE??? If I took the sparkplugs out of the engine and try it the same way would it even matter? (maybe the chambers are full of gas?? Thats the last troubleshoot opinion I got...) think it will work?

Thanks for reading my problem......Brian

[texasz]

You're on the right path I think. If the starter will not crank the engine (all you get is silence or the clicking sound) then you have a problem with the electrical. Could be a bad starter, a cable may be grounding on the chasis somewhere, bad coil (I know it's new but I have had a few things that were new be DOA), etc. I would not consider the plugs or gas in the chambers since the engine is not even cranking. I'd keep working the angle you have been and maybe someone else here will have a better idea of what it is than me.

[HKSZ]

The starter turns over but can the motor?

I'd put it into neutral and turn the motor over with a socket wrench on the crank wheel nut.

If it doesn't turn over then perhaps the bores are sticky, pull out all the plugs and spray WD 40 inside.

Another thought, you didn't happen to fry your 'fuseable links' when changing or jumping the batteries?

[Daniel]

Did you buy it like this.Have you ever had it running?carbs or F.I.?I like the "pulling the plugs".That takes away all compression ,If it doesn't spin fast then ,you have a problem.Make sure the battery ground at the starter end is nice clean and shiny metal.Also that the battery wires are good, clean .tight, haven't sucked up corrosion into the cable

[peterc]

I think that HKSZ is on the right path. First thing is to see if the engine will turn over. Use a socket wrench on the crank shaft nut and turn it by hand (clockwise) with the spark plugs out and car in nuetral. BE SURE TO DETACH THE BATTERY FIRST!!

If the engine DOESN'T turn over very easily, then the piston rings are sticking, in which case you're looking at tearing down the engine for a rebuild . :dead:

If the engine DOES turn over easily then its definitely an electrical problem. The starter is o.k ( you've already tested it), so it's probably a bad connection, corrosion, etc.

A quick way to test is to turn the key to the "on" position ( just before "start") and...(with the car in neutral of course)... use a screwdriver to short the positive/negative leads on the starter motor. This will bypass the whole key/coil/starter wiring sub-harness (i.e. you're hot-wiring your own car ).

If the car starts then you're looking for a short in somewhere between the key (in start mode) and the starter.

Good luck,

Cheers,

Peter

[240Zdragon72]

The engine will crank with the key, (now that I've installed an Optima "Red Cap" battery) I changed all the connectors to the starter. They where green.:stupid: Now the engine will turn over, but no spark. could there be a short to the coil, or should I try putting the old coil on?

Brian:alien:

[HKSZ]

Brian was this car running when you bought it?

To check your coil turn the ignition to on, pull the HT lead from the coil out of the dizzy end and expose the metal connector, with insulated pliers hold it very near to the strut nut and watch to see it arc.

Also check your points have a gap ( .45 mm).

These too will arc when opened with the ig on

Steve

[240Zdragon72]

No, Steve,

the car sat for about 4 to 5 months. He said that the hot wire to the coil might have a short to it?:tapemouth I thought I should try to trace the wire back to its oragin to see if this is true. thanks,

Brian.

[240Zdragon72]

:dead: :stupid: :tapemouth Now I think the problem exists in the fuel area. I have spark all the way to the plugs. I pulled the fuel line after the filter and tried to crank the car, No fuel. I have also found that most of the lines on the SU Carbs are rotted and so is the return line to the fuel tank at the clamp. Could it have only been the vacuum lines all along?

Brian:alien:

[HKSZ]

Try without the filter

Just another $2 part!

Steve

[240Zdragon72]

Where is the stock fuel pump located? Also, the car is equipped (I think) with an external fuel pump. Where would I start first?

Brian:alien: