need advice on 94 240sx

[osbornebe1]

Sorry if I'm in the wrong room. Nico first timer (first time chat room for that matter). I've got a 94 240sx that is surging or kicking and shutting down at lights occasionally for weeks and has now begun smoking. I've been through 3 mechanics none of their computers find anything and they have no guess what the problem is. Any suggestions would greatly be appreciated! Thanks

[wirelessalpha]

This is where you need to post:zeroforum?id=23

That said - is the smoke coming from the engine bay? Does it have a certain scent you can describe? Is the car overheating - prior to shut off?

Could be thermostatCould be head gasket (most likely)Could be faulty radiator (do you find yourself filling up the resorvoir tank?)

Faulty radiator hoses...could lead to the above problems. Might be a combination...

Then again, if you said a few good mechanics looked for that already...I dunno...I'm sure someone would have checked for leaks.

[osbornebe1]

Thanks so much for the reply.Checked for all of the leaks... seem ok. The smoke is out of the tailpipe and is very black and oily. Not using water. First mechanic (before the smoke) thought there was water in the gastank because it was as if the engine would hi a drop of water and not burn for a second causing it to puase and the lung. Have ran the tank very low and refilled severl times. Doesn't appear to be the tank. RPM ok. Other mechanic thinks it "might" be the distributor. Cost over $300. I'm not sure I want to pay that if he's not very sure thats the problem. Thanks again

[Eikon]

osbornebe1: Welcome to NICO!!!

Great to have you aboard.

A couple of ideas for you..

Have you replaced your fuel filter recently? It's possible that clogs and inconsistancies could be caused by a bad fuel fuel filter. It's a very easy and cheap replacement.

Have you replaced your spark plugs recently. It's also possible that poorly functioning, carbon covered spark plugs are causing problems with combustion. This can lead to all kinds of strange issues.. leaving fuel unburned can cause irradic combustion, smoking, jerking, etc... Should also be a pretty easy do it yourself repair.

Any idea if your fuel injectors have been cleaned recently? Try adding a bottle of fuel injector cleaner.. Another very cheap attempt.

It is very possible that you have a bad distributor as well. It could function erradically... at times not sending a proper pulse to the plugs. If it misses a pulse, you would get left over gas in a cylander from a misfire on one stroke. The next stroke would then be very rich and give you an abnormal combustion. This would also cause black smoke.

smoke: Black smoke is usually caused by excess gas burning in the cylanders. If it's consistant that means you have too much fuel pressure and perhaps you have a bad fuel pressure regulator... in other words, it's not controlling the fuel pumps flow and allowing too much fuel pressure into the cylanders. If the black smoke is inconsistant and accompanies the jerking it's most likely an issue with the issues I brought up above.

Just some ideas for you. I would start with the fuel filter and fuel injector cleaner. They are the cheapest and easiest things to start with. If they don't work, I would look into a distributor and plugs. With the help of the resources here on NICO, I would strongly suggest doing the distributor and plugs yourself. It's really not difficult work and you can save yourself a fair amount of money by acquiring the parts cheaper than a mechanic would and of course not having to pay "book time" for labor.

Good luck osborne...

Again.. Welcome to NICO.

[osbornebe1]

Best advice I've gotten yet. And the mechanics were getting paid! I'll definitely start there. Injector cleaner today and then fuel filter. I'm driving my father's mustang "toy" w/out AC and it's about 100 degrees during the day. Love the car but can't take the heat much longer. Thanks for taking the time to help.

[(Yoshi)]

That happened to me right before my injector went bad... same thing

[94_240sx]

I've replaced 3 injectors so far, but engine never shut down by itself when injectors went bad. It was shaking really bad though. All 3 times I used injector cleaner, but it wouldn't help at all, so I just replaced them. When it happens again(surging or kicking), unplug spark plug wires one at a time and see which one is not firing. If you find one, you might have a bad injector.

[(Yoshi)]

Mine only shut down right before it was realy bad and started running realy rough aka three cylinders.

[94_240sx]

Yup. That's it.

[osbornebe1]

Thanks again all!