What to do if your project doesn't start

What to do if your project doesn't start

The lads are chewing through the new Kei truck project (check the LATEST EPISODE HERE) and they're making excellent progress with the tiny machine. However, what if you're not so fortunate and your project car doesn't fire straight up?

Any engine needs three things to run: air, fuel and spark. If your project car isn't running at all, you're likely missing either fuel or spark. If you're unsure if you've got fuel try removing the feed line and stick it far into an empty water bottle with a rag wrapped tightly around the top. Hold onto the line tight and have a friend turn the car to ignition for just one second (don't turn it on) - you should see a jet of fuel splash into the bottle, confirming you have fuel being supplied to the engine.

This should be enough to make the car cough, though if it doesn't run cleanly and properly you might not have enough fuel pressure or you might have old fuel (which will stink and look very yellow).

Spark can be several issues so it can take time to work through. The key to tracing issues with spark is to be methodical and test every park of the ignition system one by one.


Straight up, you need a half-decent battery in your car and, ideally, a brand new one. Any project car will need plenty of cranking time before it eventually coughs into life and starts doing car things. 

Next up, if you haven't put fresh spark plugs into your car whip the old ones out and make sure they're clean and not damaged. It is a good idea to Google what the gap should be for your plugs, then use feeler gauges to check your plugs are right.

Throwing fresh spark plugs and ignition leads onto a project car is a sensible idea, up there with fresh oil and coolant. Just remember to throw the feeler gauge in to double-check the gap before fitting them. 

If you still don't have spark the next step is to make sure the coil packs or distributor is sending spark to the plugs themselves. On old school engines you can simply use a test light or multimeter to make sure there is power at the coil.

You can test you're getting spark at the engine by pulling each coil pack or ignition lead and fitting an old spark plug to it. Using insulated pliers to hold the spark plug, hold it 10mm off a metal piece of the car and watch for a spark to jump between the plug and the metal as a friend cranks the engine. 

If you don't see spark, then your problem is the coil packs or inside the distributor. Coil packs tend to either work or need replacing, while common distributor problems include unclean points, incorrect timing, a cracked cap, or rusty contacts.   

If the engine still doesn't run after all these checks look at the crank and cam angle sensors.

Once you get the car running you should check for fluid leaks - shut it down immediately and fix them as you find them. You should also do some small test revs to ensure the car doesn't have other problems under load.

One area many project cars stumble over is electrical gremlins related to the charge system. Sometimes this can be from a non-functioning alternator or from poor alternator wiring.

If you can get the car running, turn some electrical systems on (like headlights, stereo, and even windscreen wipers or the A/C). Measure the voltage at the battery terminals, then between the battery ground and the alternator terminal. If you see more than a 0.5-volt difference your charge wire and ground wire aren't up to the job - you should also run a ground wire from the alternator of equal gauge!


Leave a comment

Please note, comments must be approved before they are published