Hello and Please Help me with my 280Z

[SilverSurfer]

Hello all! I recently acquired a 1977 Datsun 280Z and had a mechanic do a lot of work to restore the mechanics (engine, brakes, etc.) to factory specs. However, there is still an issue. The car starts and runs great, but when it gets warmed up (about 15-20 minutes into a drive) it starts to stutter and then it shuts down. At this point it won't restart. Letting the car sit for about 5 minutes (not a long time!) seems to solve the problem - the car starts again and I can drive it until the process repeats.

Here is what has been done to the car so far:

- Fuel tank checked to see if getting clean fuel from it
- New fuel lines installed
- New fuel pump and filter installed
- New spark plugs
- Distributor checked
- AFM (Air Flow Meter) replaced
- Fuel rail replaced
- Air regulator valve attached (it was missing when I purchased the car!)

The fuel pressure was checked and the mechanic said it was good. So, my question is, what do I check next to see what is causing the car to stutter once it warms up? What other information do you need from me?

On a second note, when the car stuttered and stalled the first time I was driving it (a day out of the shop), I turned on my hazards. This caused my turn signals, hazards, and dash lights to all stop working. To clarify, my turn signals do not work at all. This means that they do not blink outside of the car, nor do the lights turn on inside on the dash. Neither do the hazards. On top of this, none of the lights on the dash come on when the lights are turned on and any electronic gauges (like the voltage meter) do not work any longer. The mechanical gauges (like the speedometer and heat gauge) work fine. The brake light for the emergency brake works. And a red light next to the voltage/charging meter briefly flashes when I start the car.

All external lights work (headlights, tail lights, brake lights), so this is not a dead bulb issue. Since all dash lights stopped working, I am assuming this is not a flasher unit issue. I've also checked fuses and fusible links and they all look good. Where do I go from here?

Thanks in advance for any help.

[EuroDat]

Hi silversurfer, Welcome to the club.

Your engine stall issue sounds a lot like the TIU is failing when it gets warm. Typical for these old cars.

The next time it does it. Pull the center HT lead out of the dizzy and hold it a couple of mm of the manifold and get someone to crank the engine.

You may want to do this test when its cold and all working as it should. That will give you a good base line to compare to.

I used and old spark plug. That way the gap in the plug would always be the same during the tests.

A second check you can do is simply check the tacho. If it starts bouncing around, its a good sign something is wrong with the ignition system.

Here is a link to my TIU conversion. There are other ways to fix a failing TIU like fitting a 280ZX dizzy, but I chose to keep the original look.

http://www.classiczcars.com/topic/49588-fitting-a-hei-module-in-transistor-ignition-unit-1977-280z/

I don't think the lights are related to your engine dying problem. More of a coincidence.

Here is a link to the Factory manuals. A must have when working on these cars

http://www.xenons30.com/reference.html

The Fuel injection supplement on the xenons130.com is more complete for the efi even though its on the s130 site. See the S130 EFI manuals section. Early version.

http://www.xenons130.com/reference.html

Chas

Edited May 7, 2015 by EuroDat

[siteunseen]

My dash lights went out and I flipped the plates over in the combo switch to fix them.  Here's what I went by;

http://www.kamikazeracing.org/dl/ZTech/Rebuild_240Z_combo_switch.pdf

 

I would recommend cleaning all your electrical grounds and connection.  If you don't have a good ground the parts will get hot and fail.  Here's some help, http://atlanticz.ca/zclub/techtips/electricalconnections/index.html

 

More of the same, http://atlanticz.ca/index.php/tech-tips.html

Edited May 7, 2015 by siteunseen

[SilverSurfer]

I just may have resloved the engine stalling/stuttering issue. I was looking under the hood and saw that the gas line going into the fuel rail was pressed up against the top of the engine. I thought that perhaps when the engine gets to normal operating temperature that the hose was getting hot via contact and causing the gas to become vapor. So, I moved the hose. It was tied down and I slid it through the tie a bit so that it 'floats' about 2" off the engine.

 

I also saw that the cable going from the distributor to the ignition coil was a tad loose on the ignition coil end. So I made sure that was firmly in place.

 

In any case, I have been driving it for about 45 minutes now, in the neighborhood and in city, so a lot of starting, stopping, and moving slow, and it ran like a champ. Next I will run it on the highway and see how it does.

 

I'll look more into the electrical issues later today.

Thanks everyone for the help!

[SilverSurfer]

Thanks for all the links, siteunseen. I will certainly be looking all of those over!

[SilverSurfer]

The 280Z has been driving well for the past hour, in city and on the highway. Now, a new issue has appeared ... the gas pedal wants to stick. I tried spraying down the linkage with brake cleaner and working it in, but the pedal is still sticking. I have to use my foot to pull it back at times.

[SilverSurfer]

Looks like the throttle accelerator cable boot is ... no more ... completely disintegrated. I suppose this helps a lot of making sure the throttle gets back to where it needs to go. So, I ordered a new one.

[siteunseen]

You can put a spring on the linkage temporarily. Maybe on the throttle rod somewhere? Or drive without shoes and pull the pedal back with your toes. : )

[SilverSurfer]

Ugh! I feel stupid. I had checked the carpet and floor mat to make sure it was not interfering with the gas pedal, but I didn't check well enough! There was a piece of insulation from the firewall that had come loose and wedged itself. Removing it fixed my gas pedal sticking problem! Now I am good to go mechanically! I just need to sort out my electrical issues.

 

Thanks again for all the help.

[Patcon]

Many times the issues with the exterior lighting is caused by the switches on the steering column or the hazard switch. They carry full current so they tend to get scorched. Read through Hazmats build thread. He reconditioned his recently

[rossiz]

re: the throttle linkage - brake cleaner will clean it, but leave it dry (and probably ruin anything plastic) so be sure to lubricate all the ball connections and all moving parts with grease.

you will definitely go through the entire electrical system in the engine bay and clean all connections (deoxit and some 400 paper are your friends) including all grounds, even if they look solid. the efi system is very dependent on all the sensors delivering their signals accurately and a little corrosion can wreak havoc. just take your time, go through each harness one at a time, unplug/disconnect, clean, re-connect and move to the next one. this will serve you well, as you will probably find more issues than you know of.

do a similar process with the vacuum lines - all of them will need replacing and don't forget the pcv hose under the intake manifold that goes to the block below the dizzy, as this gets baked from the exhaust manifold and falls apart.

[SilverSurfer]

Thanks for all the advice. I will definitely do this.