Redwing. Nice young woman needs our help.

[siteunseen]

Please don't get mad at me for starting this thread, I'm just trying to help. 

 

Redwing, on 10 Jun 2015 - 10:36 AM, said:

Reading all I can find on my problem with my '76 - 280 Z. I bought her 3 months ago, my dream of having a Z again.
I had bought an original '71 when they first came out with a 6 month wait, and no choice of color. Luck was with me and she was the Mexican Orange. I drove her for 256,000 miles with no major problems. Just little stuff. My Super car.
Mostly my newer car is hard to restart after being driven for half hour or so. But twice in a cool morning she pulled this, and was hard to start/restart. If I wait for 15 min. or so, she will start and run fine. I cannot check with my tach, as it is not working. Will this fuel filter problem cause low mpg (20 mpg and I expected more)? Another thing that might explain my problems, is a huge whoosh when I open the fuel cap. Only while car is hot, not in the a.m. while cool.
Is this a fix I am able to do myself (I am a 72 yo. Female with some mobility problems.) I do not have an abundance of $, social security does not go far, and I don't have any savings. So I am working with her problems as I can.
Any assistance will be great fully appreciated. Thank you so much.

Redwing, on 09 Jun 2015 - 09:01 AM, said:

Hello, I am a 72 yo.female which has just purchased my 2nd Z car. I bought a new '71 back when they first came out HLS30511904. I put 256,000 miles on her. My second one I have had for 3 months. It is a 1976 280 Z, HLS30277450. I had the original title, a one owner car till sold, lived in Arizona. It has several problems which the local mechanic is not giving me confidence that he knows what he is doing. The last spark plug next to the wall, has been coated with drippings from the heater hose. He cleaned it, and tightened the hose twice. Then he replaced the hose. It still is covering the spark plug with drippings. He now says the main motor gasket will need to be replaced. Not sure what to think about that, except I think that may be extreme. So I joined here to look for ideas. This post that I am responding to, sounds like what she is doing now that the warmer weather is here. (In cool weather no problem with running perfectly.) Starting and dying, but mostly hard to start while engine is still hot. And then very large chugging, hard to keep running, sometimes impossible. I do not know if this is caused by the drips on the spark plug. Or maybe by the part mentioned in the post. Another thing I have noticed, when getting fuel, on opening the gas cover, a huge "whoosh" of air happens. Gas vapor? Never when cooler out, or in the a.m. when I have checked it. Any relation to my chugging problem? With my first Z, my Dad taught me a lot about her. So I do know some about my cars workings. Thanks ahead for any insight on this for me.

 

[siteunseen]

I don't know if you saw about the coolant drip so I'll put it here.

 

"If it's leaking coolant above the spark plug at the rear, that's #6, you may have a cylinder head gasket leaking.  You could very carefully re torque the head bolts and maybe stop it but if you have to have the head gasket replaced, that is a major job unless you're a mechanic, a shade tree mechanic even."   

 

If it's leaking above the plug, it's coming out from under the valve cover gasket.  Is it coolant or oil?

Edited June 10, 2015 by siteunseen

[siteunseen]

I've got a Mexican Orange 240, favorite car of my life.

 

[SteveJ]

Just reading that there might be a leaking head gasket, my suggestion would be to try to see if there is an old Z enthusiast living nearby (Z clubs are great resources for finding someone.) who could take a look at it. The coolant should be inspected, as well as spark plugs, fuel pressure, compression, etc., etc. 

[Zed Head]

I second SteveJ's recommendation.  You need to find a mechanic that knows how to work on these old cars.  There aren't many out there.  Both siteunseen and madkaw know what they're doing and still feel uncomfortable with their mechanics.

 

The trouble starting when hot could be the common "hot start" problem.  The "whoosh" could be a modified tank venting system (some people don't understand that the charcoal canister in the engine bay is important no matter how ugly it looks).  The leaking "main motor gasket", actually called a head-gasket, is not uncommon after many miles.  My 76 engine had a leaking head-gasket.  The head was also warped, but in the opposite direction of the leak.  That's an example of a how a small job, gasket replacement, turns in to a big one - a  head rebuild

 

Unfortunately, many well-meaning mechanics will spend a lot of your money and time before admitting that they don't know how to work on the old L6 and its EFI system.  Find that local club.  Southeastern USA covers a lot of territory, more details could lead to more suggestions.

Edited June 10, 2015 by Zed Head

[FastWoman]

Hey, welcome!  Another woman!  Woohoo! 

 

The gas tank whoosh is probably normal if you're getting it in the heat of the afternoon.  The gas cap holds pressure.  There's a vent (through the carbon canister) that will hold pressure up to a point and then release anything further.

 

Coolant leaking onto a spark plug is strange.  The head gasket ("main gasket?") is located beneath the spark plugs, so I wouldn't think it would be the source of coolant leakage onto your spark plug.  Perhaps you have a pinhole leak somewhere, and there's a bit of spray.  It wouldn't hurt to replace the hoses.

 

It's more likely you have motor oil leaking from your valve cover onto your plug (not a serious issue).  Is the liquid green or brown?  Is it sweet?

 

The "hot restart" problem is a known and typical issue with the 280Z.  There are several theories.  Mine is that the early fuel injection designs were meant for different fuel formulations than we have now, and they had issues even then.  When you shut off the engine, heat soaks the injectors, which are normally cooled by fuel.  When they get hot enough, they vaporize the fuel, and they will only blow vapor into the intake until they cool off -- not enough fuel to fire the cylinder.  The problem is made worse with ethanol gasoline (more volatile than old-fashioned gasoline), and it's even made worse by winter blend ethanol gas (which is even more volatile than summer blend, especially if you have it in your tank when you run the car during the summer).  The problem is worst if you let the car sit for 20 min.  After about another 15 min, the car becomes much more startable.  If you're in a rush, you can hurry the process by popping the hood and letting the engine cool.

 

The design problem was partially remedied in subsequent years by: (1) creating webbing between the intake runners to block airflow from the exhaust ('77/'78), (2) shielding around the exhaust -- between exhaust and intake manifolds and around the exhaust manifold ('77/'78, I believe), (3) putting vents in the hood ('77/'78), and (4) eventually providing a cooling fan for the injectors that runs after engine shut-down (280ZX generation).

 

FAIW, these cars are very easy to work on, although a head gasket might be over most people's pay grade.  You can download a Nissan factory service manual from the "reference" section of www.xenons30.com.  It's one of the best service manuals I've ever seen -- far and away better than a Hayes or Chilton's.  It's what the Nissan service departments would use, but Nissan also sold copies to owners for maybe $80.  If you prefer paper, like I do, you can probably find a used one on ebay or Amazon.  Make sure it's for your year of car.

Edited June 10, 2015 by FastWoman

[Zed Head]

Good point on the spark plug well leak.  I didn't think that one through.  Another possibility case is a cracked head.  Hopefully not.

 

My gas cap doesn't whoosh, and the system seems to work fine.  Could be that my check valve is weak though.  Copied a picture just to show all of the parts of the system.

[Redwing]

I will answer a couple of you at once. The drip is coming for above the spark plug, the liquid appears tan not green.

Before I got her, she was shipped from Miami to Jacksonville where my friends live, and they had their mechanic go over her doing things like plugs, oil, and a couple small rust spots, etc, checking her out.

My friend has rebuilt Chevys all his life. After the mechanic finished with her, she was shipped on to Georgia to me. There are a few things that I wish he had attended to, but perhaps he did not have time. I found out later his wife is very ill, so that could be part of it.

I have a book that I purchased online that covers Z cars from 1970 through 1976. it is a service repair book, written by Alan Ahlstrand. It is a very complete hardbound book far superior to the Haynes. I have referred to it a lot.

I found out that I did not have enough money to restore my 1971 z. I was told it would be $15 to 18,000.,. which I did not have. So I purchased this 1976 instead. I hate seeing my old car just falling apart.

as soon as I figure out how to do it, I will post some pictures, including one of the spark plug that has the leak on it.

Thank you all for your offer of help.

[SteveJ]

Unfortunately, tan could still indicate a problem with the head gasket (or head). Seeing it on the spark plug just means there is a valve cover gasket leak, too. The oil and coolant can form an emulsion that can look tan. I frequently see people describing it as "chocolate milk". Send me your contact information, and I'll pass it along to Chet Wittel to see if he can take a look at your car. If he can't, I may be able to, depending upon whether or not I have spare time before the ZCCA convention.

[siteunseen]

Oil plus water/coolant equals tan. Not good. I would loosen the bolts on the valve cover and pull it off. Take some pictures of what's under there.

We can 'splain the upload procedure.

[FastWoman]

Yeah, "tan" isn't a color anyone likes to see.  Rather than a "milky" tan, is it perhaps just a clear, light brown?  If so, that would just be motor oil.  A new valve cover gasket would be cheap and easy.

 

You can also pull the dipstick to check for chocolate milk, but a look under the valve cover would be even better.  If you haven't done your first oil change yet, you'd see it in the drain pan also.

[Zed Head]

Aside from engine mechanical issues, 1976 comes with EFI, unless somebody swapped carbs on to your engine.  It really could be a project if you don't find someone who knows the system.  It's fairly simple but has it quirks.  A mechanic who isn't familiar can really make a mess of things.  Once they're dialed in they're very dependable, on a daily basis.  But when they have a problem they can be a nightmare.