Engine Wouldn't Start - Good Lesson for all of us

[Kevin Shasteen]

In the last few months my 1978 280Z 2+2 became slower and slower to start: on a cold start or a hot soak start. Last week I went out to drive the Z and the engine just turned over and over and over without ever starting.

 

I could smell the fuel coming from the intake so I knew I was getting fuel. I pulled a few spark plugs just to make sure and confirmed the plugs were getting plenty of fuel.

 

Keep in mind this whole time my Z has about 200,000 miles on it and is bascially bone stock: it still has 4 original injectors on it. Anyway, I began checking if I was getting spark to the usuall suspects:

 

1) Fusible Links...checked out good

2) Fuse Box....checked out good

3) Coil was getting +12 to the coil but no spark out of the coil

4) Pulled a coil from my International 4x4 and swapped it on to my Z; and my Z still would not fire.

 

(I was so sure I would have to buy an ignition module or ignition relay )

 

5) Decided to pull the coil off the Z again

6) This time I scraped the Coil Bracket mating surface clean with a wire brush

7) I also scraped the maiting surface on the fender apron where the coil bracket mounts.

8) Remounted the coil on the Z

 

Upon cranking the Z this time it cranked for about 10 seconds and then fired up. Woo-Hoo! Killed it and re-fired it three more times just to make sure it wasnt a fluke. Each time thereafter the engine fired up in about 2-3 seconds the way its suppose to start.

 

Just wanted to relay to everyone who has engine prob's: sometimes the best thing is not to replace a part - instead, sometimes the best thing you can do is to remove and scrape the ground's mounting surface to all the wiring connections. My Z may be original...but she's get'n old. I'm almost afraid to start her up these days, just knowing how hard some parts are to find.

 

I guess when she finally gives up the ghost it will be V8 time.

 

I cetainly didnt want to replace an ignition module or ignition relay...as expensive as those parts can be from Nissan or some other parts house.

 

I believe I got lucky this time...just thought I would share my story just in case someone else ever experiences what I experienced.

 

Kevin,

(Yea,Still an Inliner)

[johnc]

Another good thing to check when these symptoms occur is the negative cable from the battery and any chassis grounds.

[Kevin Shasteen]

Well the saga continued for a little while longer.

 

After thinking I fixed the problem, which resulted in my initial post on this thread, I drove the car later that week into town only to realize my problem was still there. Luckily I was able to push start the car to get it home.

 

This was puzzling to me. Why would it start up perfect on a cold start yet refuse to start on a heat soak start up.

 

As the previous post implies the engine was getting plenty of fuel so I knew the fuel pump and injectors were working.

 

I had a hunch it might be the transistor ignition module or an ignition relay (again). So I consulted the Factory (Life-saver) 1978 Datsun 280z Service Manuel for testing the transistor module.

 

There are about 5 tests you can perform on the module with 4 of the tests being conducted with a multi-meter and 1 of the test being done with an Oscilliscope (sp?).

 

The fourth test indicated my distributor's pick-up coil was defective. So I removed the cap-rotor to check the air gap....which is only suppose to be between .008" to .016". Mine measured right at .065"; it was a wonder my engine even started at all.

 

I adjusted the pick-up coil's air gap to .010" and the car fired up immediately.

 

That Factory Service Manual has saved my wallet more money than I can shake a stick at.

 

Anyway-just wanted to relate the final (hopefully) chapter to this saga incase someone else finds themselves in the same spot.

 

Its been a crazy saga that began about a year ago with a fuel relay. This then transitioned into the dead battery-bad alternator game, then some inline fuses, an ignition relay, some bus fuses, an ignition coil along with a non-factory blue wal-mart plastic bag being sucked up into my air filter housing. All this over the span of a year.

 

I beleive I finally have the ole gremlins whooped: Yee-Haw!

 

I guess the moral to this thread is to never give up on these old cars that most of the previous owners neglectedl....AND to be sure and find yourself a Factory Sevice Manual for your year/model Z.

 

Kevin,

(Yea,Still an Inliner)