280ZX Stalls and Restarts an Hour Later

[XoXSciFiGuy]

Hi, I'm a newbie from the Seattle area, but definitely a Nissan guy. I own a 1997 D21 XE KingCab with a mere 112,000 miles. It''s like new, has NO issues at all. Wife drives a 1998 Pathy, but she's going for an Xterra soon. 

The problem I have is with my just-purchased1982 ZX. (Two seater, five speed, non turbo) Starts up and runs great, sure. A few blocks later, it just dies cold. Engine cranks, but no start. An hour or so later, it starts right back up and then does the same thing a few blocks later. 

This one is worth fixing up, too. Body straight, no issues with clutch, engine, no smoking or knocking. Only 126K on it, new five speed tranny, and a paid a measly $1,000 for it. It even came with a box of parts...brand new fuel pump in the box, fuel filter, set of wires, plugs, cap and rotor...and I'm putting those in tomorrow. After I do...the engine will start up of course. I will let it run until it dies and then check spark. If spark is good...it almost has to be a fuel problem...and we can eliminate the pump and filter...so if it dies after all that...and spark and air are good...what do you think? Regulator? Fuel damper by the pump? 

I'm pretty sure it's not the pump because even after it dies with the one installed right now...you can still hear normal whirring and shutoff of the pump when you turn the key to ON. 

Any suggestions would be appreciated. My thought is that if it gets good spark AFTER it dies...and still won't start after all those part replacements...could be the fuel regulator maybe?

ABOUT THE Z PICTURE:  This was a picture of the car when I bought it. Since then, we did polishing compound, clay bar treatment, and clean and wax. I don't think this is the original color, either. Paint code shows Jade Grey, but the door jambs and underhood show darker than this...which looks more like a Forest Green to me. They definitely don't quite match, but whoever painted it did a clean job. At first, I thought it was just sun-faded and it really WAS Jade Grey, but the outside paint is just way too even to be sun faded. And when I picked up some touch up paint for it using the paint code...it matched the underhood, the door jambs, yes. But not the body, which is definitely more of a green. Notice the hood is oxydized. That's why I used the polishing compound and the clay bar on the body. 

Edited August 26, 2018 by XoXSciFiGuy

[dutchzcarguy]

Nice car for a few penny"s!  was it hot weather?  I ones had that problem with low fuel on a hot day, it's getting to hot under the hood and fuel evaporates in your lines on the engine and it stops.. after some cooling you can start it up again..    At low fuel the fuel gets hotter and you end up with to hot fuel.. this is not the case so fast with a full tank..   also has your car the fuel injector cooler, that plastic tunnel thing over the valvecover?  that also cools the fuel ..

[XoXSciFiGuy]

No, not hot weather. No FI cooler, either. I don't think it's a heat problem because the car will only run about five minutes before it stalls. Starts back up an hour later. I still think it might be the fuel regulator. After I change out those parts, I can narrow it down. Was just wondering if anyone had a similar problem. 

Picture posted below of my July trip to the Olympics in the D21. 

 

Edited August 26, 2018 by XoXSciFiGuy

[Patcon]

Start with a fuel pressure gauge. You need some real information. That will tell you if fuel pressure is dropping off when it dies or if it's spark. Spark could be a bad module or coil overheating.

Could even be rust in the fuel tank or several other things. You may have to add a test port in the fuel line after the under hood filter

[siteunseen]

When it's running again pinch the fuel lines, checking to see how hard they are.  If you can squeeze them fairly easy then there's low pressure.  Check the supply to the fuel filter side and then the output to the fuel rail.  Won't add any cost to that high price you paid. 

[XoXSciFiGuy]

I will try those things and get back here with the results. 

[XoXSciFiGuy]

Well, I switched out the fuel filter and the three fuel lines around it. (They were pretty old) Still does same weird thing. Starts right up when cold, no problem. Runs maybe three minutes...dies flat on its face and won't restart for an hour or two. But when it DOES restart...it fires right up quick. I have never seen this before, but neither have I ever owned a Z until now. 

Pulled some interior trim parts from the hatch area and glued the vinyl back down on them. Will start it up tomorrow and let it run until it dies...and then do the spark test. Tell you what, though...even though I relieved the fuel pressure prior to switching the filter, a LOT of gas came pouring out of the lines. I don't think its having any fuel pump problems. I still think its either fuel pressure regulator or maybe coil overheating. I should know more tomorrow. Had to work today so I didn't have a lot of time to work on it. 

My OTHER rig is a 1997 KingCab XE, two wheel drive, with a measly 112,000 on that. Now that truck...it has ZERO issues. I mean everything works like a dream. 

I was wondering if it could be the cold start valve? Maybe if its bad...when the car warms up a bit it would die like that?

[Zed Head]

On 8/26/2018 at 12:12 AM, XoXSciFiGuy said:

. My thought is that if it gets good spark AFTER it dies...and still won't start after all those part replacements...could be the fuel regulator maybe?

The ZX distributors and ignition modules are known to be flaky.  The distributor has a magnetic ring inside with six spikes that ride very close to the six spokes of the reluctor.  The bushings are weak and tend to let the points contact, breaking the magnet.  You can usually see that by eye, wiggle the rotor and see if things move.  

The ignition module on the side is electronic and overheats when it goes bad.  One test for that is to spray the module with some sort of cooling spray, or apply an icebag to it.  If it responds to cooling that's a sign.

It has many of the signs of bad electronic ignition.  The coils are durable though, the other parts, not so much.

[siteunseen]

To add to Zed Head's informative post.  A cheap can of keyboard cleaning spray, $.99, is a good cooling spray.

The magnetic do hickey.  Good read on rebuilding one, lots of info.  http://atlanticz.ca/zclub/techtips/distributorrebuild/index.html

Edited August 31, 2018 by siteunseen

[XoXSciFiGuy]

Well...I got a new ignition module shipped to me...and it was the two-connector type, wrong one. (Returned immediately) THIS ZX takes the THREE connector type. Still same problem though. Runs for a few minutes and then dies. No spark on the restart attempt. A few hours later it will start up. I have noticed the length of time it will run is getting shorter every time though. 

Correct module ordered. Should arrive in a few days and then I will update. I bought a new coil but didn't yet install it. I noticed it was smaller than the original coil already in the car, although I'm not sure if that matters. 

NOTES: These pictures were taken BEFORE we brought the car home. Since then, all new air and fuel hoses have gone in, new plugs, cap, rotor, wires. Carpet replaced. New oil and antifreeze. Engine bay was detailed as well. 

Edited September 9, 2018 by XoXSciFiGuy

[Zed Head]

On 8/31/2018 at 10:49 AM, Zed Head said:

The ZX distributors and ignition modules are known to be flaky.  The distributor has a magnetic ring inside with six spikes that ride very close to the six spokes of the reluctor.  The bushings are weak and tend to let the points contact, breaking the magnet.  You can usually see that by eye, wiggle the rotor and see if things move.  

The ignition module on the side is electronic and overheats when it goes bad.  One test for that is to spray the module with some sort of cooling spray, or apply an icebag to it.  If it responds to cooling that's a sign.

It has many of the signs of bad electronic ignition.  The coils are durable though, the other parts, not so much.

and post #9.  No offense intended.

Many of us have found that it's most effective to really dig in to examining and testing the parts first.  Just saves time, money and effort in the long run.  You can test resistance on the coil and the pickup coil in the distributor while it's in a "no-start" state. 

You have one of the unique opportunities where the part, whatever it is, stays "bad" for an extended period of time.  So, start-die-test-test-test, until it starts again.  Then repeat until you find the broken part.  It's probably electrical so a multimeter and some time should do it.

[Zed Head]

Here's a possibility, related to heat.  That third pin on the ignition module is actuated by a thermal switch somewhere, I think.  So it might actually be the ignition module.  I think that you can test that by short-circuiting the switch or the module.  You could explore that by examining the FSM chapter to see how, exactly, it works, in the meantime.