DATSUN Z CAR WON’T START?
You just spent $1000’s on that new project car, but it won’t start… Let’s dive in.
THE Z CAR
There it was, a Datsun for sale just waiting to be bought. We called the number on the car and $1800 bucks later we had a 1981 Datsun 280ZX in our garage.
Unfortunately we had to tow it home because it was completely dead.
We picked up a fresh battery, ordered some new spark plugs, spark plug wires, distributor cap, and rotor. The existing spark plugs didn’t look too bad, so we thought the engine was OK.
After we replaced the spark plug wires it was onto the distributor cap and rotor. Then we went to start things up. The starter cranked the engine, but the engine just wouldn’t start.
Basically there’s three things you need; air, fuel, and spark.
Now those three things do need a bit more fine tuning, but if your project car won’t start check to make sure you have air, fuel, and spark.
Here’s what we did to check each on our broken down project car:
AIR - We first checked to make sure as we started the Datsun that the throttle body was opening to give the engine some air. Before the throttle body, the intake on the 280ZX has whats called an air flow meter.
There’s a flapper on the air flow meter and we verified it was opening during start up. The throttle body also was slightly opened during startup and if we hit the gas pedal everything opened and closed properly.
FUEL - The second thing we checked was fuel. We added some fresh fuel as the gas tank was nearly empty before we tried starting her up.
We could hear the fuel pump kick on and our fuel pressure checker verified we had the right fuel pressure making it to the fuel rail.
We also verified that the fuel pressure regulator was also working correctly when we disconnected the vacuum and added it back.
SPARK - The last thing our engine needed was spark. So we took off one of the spark plug wires to see if we could see a spark arc across a spark plug still connected to a spark plug wire.
Well, we saw nothing. No spark.
Meaning that all that fuel and air entering the combustion chamber was never going to ignite.
We then went back to the main spark cord plug that went between the distributor cap and the ignition coil.
We put a spark plug onto the spark plug cord coming from the ignition coil and grounded the spark plug.
Then we cranked the engine and still no spark. So it looked like the ignition coil wasn’t providing a spark. So we bought a new ignition coil, replaced the old one and tested everything again…
We put the key into the ignition, gave it a crank, but the engine was still struggling to turn over. Then it almost started.
A few more cranks and a few more presses on the gas pedal… our project car finally started.
Just like that we had air, fuel, and spark. The engine didn’t sound great and it almost died, but at least we were able to get the Datsun Z car up and running.
So remember, air then fuel, and spark.
