I recently purchased a 1979 280zx n/a. I bought it not running. It had been sitting for quite sometime, and I can not get it to run. I have replaced the fuel injectors. I am getting spark and I am getting fuel, but the engine will not fire. It just turns over and over, but never fires. Anybody have any suggestions? Are there any sensors that would keep the car from starting. Any help is welcome.

 

How did you verify you are getting spark? Did you replace the spark plugs? They do go bad from setting.

I would try spraying some starting fluid into the throttle body. Just pull off the boot for a second and open the plate with your hand. Spray some fluid in there and then slip the boot back on without tightening it. Crank the engine over. It should fire or backfire. If it doesn't, I doubt you have good spark or any at all. Starting fluid is highly explosive.

 

I have checked the spark by taking the plug out and cranking the engine and watching the spark jump from the plug to a bolt on the strut tower. The plugs probably will get replaced soon though. But we are getting spark and fuel. The spark may not be big enough, but how would i check that? Thanks for the advice though.

 

like bleach said id try spraying some chemtool in the intake while you have someone cranking the engine... if that dont work.... check your timing...

 

Alright, I will try the starter fluid in the intake and see what happens.

 

you might want to ensure that the plenium between the air flow meter and the throttle body is tightly attached and free of any holes. this will definately cause the "no start" problem you are having

 

when i sprayed the starter fluid into the throttle body some of it came back and leaked through the hose between the air flow meter and the throttle body. should i replace this hose? im not sure how that would stop it from starting but i dont really know too much about what i am doing.

 

did you open the throttle up so that most of it went up into the intake manifold? ...and since all of this leaked out, I assume you didn't crank the engine over. Most of that fluid should have been sucked into the engine when you tried to start it immediatly after the starting fluid was sprayed in.

 

We did crank the engine, and still nothing. I guess it is the spark, but we are sure we are getting spark. Could the spark be to weak? And what would cause it to be too weak? We are getting new plugs today. Hopefully that will help.

 

sounds like timing... set the car on top dead center and see if the rotor in your distributer is pointing to #1 plug.. if not your timing is off...

 

I think your right. How do we go about fixing it? I have never really messed with timing before, so I need some advice on how to go about it. I know the #1 piston need to be at TDC and on the compression stroke, but how do I check if it is on the right stroke, and how do I change if it is not? Thank you all for your help

 

Weak spark could be as simple as bad spark plugs. I had a Z set for 3 months after I had bought new plugs for it. It wouldn't start and I had spark using the same test you did. After I repalced the 3 month old spark plugs, it fired right up!

 

I replaced the spark plugs today and it didnt make a difference. The spark seems to be good but im not entirely sure on how powerful the battery for the car should be. Mine has 630 cold cranking amps and i figured that that would be plenty. I plan on checking the timing next. If anyone has any advice im open to anything. Thanks for the help everyone has put forth.

 

Help me, help you... What type distributer is on your ZX? Type (a) has points, (b - usualy fuel injection models... is a transistor/magnetic spark advance). since you have ruled out the plugs, that doesn't automaticaly mean your wires are good. Older wires or even brand new cheap sets can have you running in circles... what do you have? From end to end on any plug wire (with a digital Ohm meter) should read .25 ohm or less (and go ahead and give the wire a few shakes with the meter on it to make sure you have solid continuity).

 

alright, here is a little update. We found TDC on the compression stroke, and took the distributor cap off, and found that our #1 plug wire was not where it should have been. So we switched the wires and tried again. We now can get the engine to fire, but it still will not start. What now?!?!?!?!?!? Once again we are very grateful for you guy's help and advice. And the distributor is the magnetic spark advance type.

 

if the starting fluid leaked out of the hose between the afm and the t/b when you sprayed it in there, then your hose is leaking. it really sounds like this is the problem. to be sure take the hose that runs from the air filter box to the air flow meter off. its gonna be kinda tricky. once its out take a screwdriver and use it to operate the little flapper inside the afm. have someone sit in it and turn it over and while they are doing this, push the flapper in ablut half way. it will probably be easier to do this if you also take the 4 10mm bolts out of the mounting plate for the afm. if it tries to start even sputtering, then you need to replace your hose. it took me about 2 hours to find this problem on mine once. it ran fine i changed the clutch and it wouldnt start for anything. turns out that i had ripped the hose a little. i replaced it and it runs like a champ.

 

OK... That magnetic advance is the Reluctor, remove the rotor button and look at the six point pole piece... check the air gap between the point on the pole piece and the "hump" on the reluctor, use a feeler blade... the gap has to be between 0.012 and 0.016 in. (0.3 to 0.4 mm) if it's outside of that range your car won't run. You may need to loosen and turn your distributer to line up these two points to check (especialy if your out on timeing), mark everything for quick re-alinement. There are just two screws to loosen that allows you to adjust this gap. There is also a phase adjustment possible.... but I wouldn't go there just yet.

 

Well, we ordered a new boot to replace the one between the AFM and the throttle body. The old one had a hole, and you guys claim the car wont start with a hole in the boot, so in the next couple days the Nissan dealer will call. In the meantime, I will do what MrPlaywell suggest and check the air gap. Will give an update if anything new comes up

 

Holy ****, it started. We just came home, and tried it again, and it finally fired up. It is smoking a lot out of the exhaust(maybe the gas in the oil from flooding the car so many times???), and it is leaking some fluids, i.e. water from thermostat housing, and something that is probably oil from seal around oil pan. But now we have something to work from. Thank you all again for all the help you have given us, and you can expect to be hearing from us more in the very near future.

long live the Z...hopefully

 

Did you do anything to the car or did it just set for a bit and then it started?
Fill us in.

 

Did you check or change anything?

 

Well, it happened so fast that I am not all to sure what we did, but I remember we took the boot off between the AFM and the throttle body, and opened the flap in the throttle with a screwdriver, and cranked it over. We had also put a new battery in a couple days before, and it was obviously running low on juice from trying to start it so much, so we jumped the battery while we were doing it. And it started. We let it run for a little bit, then shut it down. We then tried to start it again, without the screwdriver, and after playing with the gas pedal alittle, it started again. After several times of doing the same thing, we took the battery out and charged it. Now it starts without fail every time. It is actually really easy to start. We have been driving it around short distances, and it is still pretty rough. It still smokes alittle, and it backfires. We are going to do the timing. As for now, we have a couple people who want to buy it for $1000. We are most likely selling it if we can get that much, seeing as we only payed $250 for the car, and spent $250 to get it started.

 

Well... If I had known you were just looking to sell it........ Oh nevermind. I think I would rather watch my `78 Z burn up and have to start all over, before I'd sell it.... anyway.

 

Now hold on Mrplaywell. We never planned on selling it. We had every intention of keeping it. But we had a couple people make offers we couldnt refuse. Hell, we spent $500 and a couple months on the car, and can sell it and double our money. You will be happy to know that with the money we get from the car, we will get a new Z to work on, one worth around $1000. We are looking for an older Z, preferably 240 or 260, just not another ZX. We love Z cars just as much as the next guy, and are not just looking to make money.