Datsun 260z stalling

[nemski]

Hi All

 

Bought a 260z recently from a friend of mine. Has a 280z motor in it, with dual SUs.

 

Problem when I got it was it wouldn't start. Thought it was out of fuel so I put about 4L in and just a little bit in the carbies to get it started, as well as replacing the spark plugs.

 

Now it starts, but backfires, with white smoke coming out of the carbies, then stalls. Engine also won't rev higher than idle no matter how much you put your foot down.

[Zedman240®]

First thing that I would do is check your ignition system ie timing/firing order. Sounds like its wayyyyyy out. If you have a timing light, clean up the scale thats on the front where the crankshaft pulley is, dab some liquid paper on the timing mark on the pulley then while its cranking, check the timing. Hope it helps!

[nemski]

I'm going to replace the fuel filter tomorrow.

 

I have a timing light but the engine won't run enough for me to time it. Might get the girlfriend to sit behind the wheel while i'm doing it

[pauly_adams]

have you checked your points, rotor button and dizzy cap. when i got my zd the ignition system was shot i had to replace everything, dizzy internals, leads, plugs etc also you could have some water in your tank it also produces the same symptoms.

 

lets us know how u go

 

cheers pauly

[Scoota G]

Maybe check out this thread

 

http://www.viczcar.com/forum/index.php/topic,2992.0.html

 

ol_skl had some timing issues as well.

[nemski]

It was running fine before I put it on the trailor and bought it home, so I suspect it's fuel related. The tank doesn't have a cap on it.

 

I'm going to have to drain the fuel to change the filter, i'll take a look and decide if I need to flush the tank.

 

Thanks for the posts guys

[nemski]

Ok so I replaced the fuel filter and it runs a little better now... not backfiring as much, but still can't get the revs up. It starts, but stalls if I take my foot off the gas. Then after keeping my foot on the gas for 30sec it kicks, with smoke coming out of the carbies, and dies.

 

Points look OK, and ignition coil is giving enough juice.

The battery is pretty dead, but once it starts the Alternator should kick in ??

Alternator is fine.

 

To me it sounds like the fuel lines are clogged to some degree... Any other ideas?

[reverendzed]

I'd pull off the fuel hose after the fuel pump and see what kind of flow you have, I think you will find it's an issue with your carbs but who knows?

rev.

[nemski]

I pulled the fuel hoses off from tank to filter, filter to pump then pump to undercarriage metal hose and all are clear.

 

What would I need to check in the carbies?

[nemski]

Found the root cause of the issue.

 

Backfiring and stuff is due to Carbies not being in tune (obviously) but the main issue was a faulty spark plug (which was brand new).

pulled the spark plug leads off each cylinder to see which one wasn't firing. Discovered number 5 wasnt' working. Chucked the old spark plug in and it worked a charm

[nemski]

OK, now it's not running fine. It's not even starting any more.

 

I checked all the other spark plugs by replacing them wtih the old ones and still no go.

[Mr240z]

Mate get a professional in or you,ll be there for the rest of the year

Outlay some cash and get it going!!! Your going backwards

[pauly_adams]

take the set of spark plugs back, i went through 2 sets of brand new spark plugs from supercheap mind u that was after i had replaced my intire ignition system. i ended up calling my mechenic and told him that i had a faulty plug, he said take them back and go else where (my mech said that they probably had droped the box causing them to fail due to them being damaged ) so i did i went to repco and sure enough my zed ran like a treat, since those two time i have never bought plugs from supercheap again.

 

my advice buy a new set of plugs from someplace that cares about there service like repco or bursons.

 

cheers pauly and good luck with it

[nemski]

Ok, finally fixed it. The Dizzie for some reason had moved all the way forwards putting the timing COMPLETELY out of whack. Moved it back a bit and it starts

 

Quick question, I want to get the timing right but there's no marker on the crankshaft. I'll mark it myself, do I mark the crankshaft at 0, when the engine is at Top Dead Centre? From memory I find TDC by taking spark plug out of number 1 cylinder and putting a screw driver down to feel the piston come up. If I can feel compression while cranking the engine, then it's the firing phase not the exhaust phase. and when piston is all the way up, i'll mark the crankshaft pulley at 0? Does this sound correct to anyone?

[pauly_adams]

there will be a small grove or a cut out part on your crankshaft pully to make it a bit easier to find id take off your dizzy cap, leave the leads pluged in bar the one going to the coil then turn your car over till the rotor button matches up with the lead going to cylender one ( the cylinder closest to the radiator ) that should put the timing mark near the timing plate. also i would put a dab of white out on the mark/ grove, cut so you can see when you use a timing light.

 

i hope this helps if you still run into trouble pm me and ill take some pics for you, one more thing please dont put a screw driver in your cylender if push comes to shove just take out spark plug one and place your finger over the hole im sure youll know when its at top dead centre.

 

cheers pauly

[nemski]

Thanks heaps for the help so far guys, you've been great. I managed to find top dead center by taking out the number one spark plug, with a torch and a 27mm spanner

 

However the engine seems to be intermittently miss firing, while sitting at the same idle speed and same timing. I'm going to do some more things (tune it properly, replace points etc.) and see how things go.

 

Thanks again