I'm new to 240's and mechanics in general. I bought a 71 240z that was running fine but I let it sit a couple months while moving and now it won't turn over. I've started to buy basic tools and am now moved in and want to get my weekend car running. I'm smart enough to figure out it has spark but am hesitant where to go from there. I've never worked with a carburetor and would like to start learning.

I've been looking online at carb cleaning sites assuming that might be the issue, but don't know how to be certain or which precautions to take when removing/cleaning the carbs.

You might want to check if you are getting fuel to the carbs. Could be a dry fuel pump which can take a long time cracking to get fuel back up to the cabs.

Good luck, take your time and dont give up;)

EuroDat is on the right track. You have spark, now you just need fuel and air. Is the fuel filter on your car clear? If so can you see it filling up with fuel or see the fuel moving? If not your pump may be going bad, could be a clogged fuel line, or possibly bad gas. Is your fuel pump mechanical or electric? Have you try spraying some starting fluid in the carbs and seeing if the engine fires up? Where in TX are you located?

Since it was running fine a couple of months ago, you probably have a fuel issue as pointed out above. Don't start taking things apart just yet, check out everything above. Good that you checked for spark. Do a visual on the carb linkage and choke actuation to make sure everything is moving properly. Don't grind on the starter for long periods or it will overheat and burn out. Keep us posted.

Hey guys just had a chance today to check this again. I bought some starting fluid so I'll give that a shot tonight. I don't have a clear fuel filter so is there an easy way to check for fuel flow?

I'm in Corpus. I was in Austin last weekend to see family. I saw a nice grey/black 240 up there driving around south congress. Motivated me to get back in the garage this week.

Edited October 2, 201212 yr by Haehl

Iwill jump in here. I had the same prob. It would run fine if I started it often, but if it sat, it wouldn't start. It turns out it was the electric fuel pump.

I would agree. Prob a fuel problem..

First, make sure there's gas in the tank. Sounds dumb, but its easy to miss if you're focused on it being a mechanical problem.

Next, Nissan designed the Z with two fuel pumps. An electric pump at the tank and a mechanical pump on the front of the engine (right side). Turn the key to "ON" and make sure the electric pump is running. you should be able to hear it. If not, buy a universal pump from any auto parts house. Just make sure it is for a carb veh and not for fuel injection. (I should also add that you need to make sure that the PSI is correct for your application [i.e. twin S.U. carbs, tripple Mikuni's etc..] There are a lot of threads on here to answer that question for you if you search it).

If that's not the prob, remove the fuel line AFTER the mechical pump and turn the engine over. There should be fuel pumping out (be sure to have a container for the fuel to go into. I used a throw away tupperware container).

As stated above, you need 3 things for combustion, fuel, air and heat (spark).

Hope that helps.

Chris

I'm new to 240's and mechanics in general. I bought a 71 240z that was running fine but I let it sit a couple months while moving and now it won't turn over. ...snip... I'm smart enough to figure out it has spark but am hesitant where to go from there.

You mention it will not turn over, then you say it has spark. Do you mean that the engine WILL turn over, but that it won't START? Not trying to beat you up over it, but not turning over would say bad starter or need new battery or at least charge the old. You wouldn't be able to tell what kind of spark you had.

Spark says the engine (and therefore the dizzyy) is rotating and that is why you're getting spark when you check, but without it starting, you're back to fuel or air.

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...snip...

Next, Nissan designed the Z with two fuel pumps.

No they didn't.

While they always had the provision in the electrical system for an electrical fuel pump, at least as of the 71 on.

(Haven't been able to locate a good 70 diagram, the "Basic" S30 diagram did NOT show the electric pump.) They NEVER installed BOTH an electric and a mechanical pump as far as anyone has reported.

The electric fuel pump was more heavily relied on once the problems with vapor lock surfaced in the 73's and on.

However, since the OP's car IS a 71, it is highly doubtful that he's equipped with an electric fuel pump unless it was added later.

Even then, running BOTH an electric AND a mechanical pump would more than likely generate MORE problems than solve, that's why the dealers would block off the mechanical when activating the electric pump feature and not run both.

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FWIW

E

Well, I don't know about diagrams, but My 73 had both.

Either way, it is simple to check. The electric fuel pump (IF SO EQUIPED) will be mounted in front of the tank. So jack it up and take a peek.

You mentioned you didn't have a clear fuel filter. Maybe you should invest in a fuel filter in with the design of the original that's also see though. They sell one that works great at Autozone for about $4.00. You could also try unhooking one of the fuel lines past the fuel pump and see if anything shoots out. Also, how new is the fuel pump? They function with a rubber diaphragm that can dry out and crack over time. That might of gone bad while it was sitting and you'll never get fuel to the engine! When was the last time the car ran fine and was safely drive-able? Like stated above, there could be a clog in the fuel system which can be fixed by blowing it out or soaking them with a strong carb cleaner.

It's nice to hear of another Z in Texas. Do you have any pictures to share of the car?

Chase

One way to see if there's gas in the float bowls: pull the hose (if it has a stock air cleaner) off the float bowl vent. Get a little straw from the wd-40 or carb cleaner spray can and stick it down the vent hole. It should rest lightly on top of the float. When you push it it goes down 1/2" or so - you can easily tell if there's gas.

I got in the garage to start looking into possible problems and it wasn't hard to find a few quick. The battery was dead so that's at autozone being charged now. The rest are marked in the picture below.

The red circles mark a hose that broke in half. I'm guessing it's a brake line. The brakes have never been great in the car but I hope it hasn't been like this since I bought it. I guess I'll have to replace that and learn how to put brake fluid in the car. Any suggestions on type of fluid and links on how? The guy at autozone suggested going to a local hydraulic shop to get a line made to replace the current one.

The green circle is where there was a vacuum line coming from the back of the air cleaner was cracked and no longer on that metal part circled. Would this be the cause of my starting problems?

The yellow circle is just some random wire hanging and just wondering if it should be there.

The orange X marks a cap that just pulls right off. It doesn't screw on easily just pulls off. Do I need a new cap?

Also, where is the fuel line I should attach the clear fuel filter to?

Do I spray carb cleaner directly while they're still bolted on or do I have to remove them first?

Thanks guys. I'm learning its just a slow progress. Hopefully I can get back into the garage tomorrow but I probably can't get that brake line until Monday if work doesn't get in the way.

Here's a picture when I bought it. Since this picture I've raised it up a bit to make it more drivable

Edited October 20, 201212 yr by Haehl