2003 Honda Civic Diesel - Won't Start When Engine is Warm

Does it have glow plugs?

In modern engines the glow plugs do not operate when the coolant temperature is above a set limit. If the cylinder compression is down from "high" mileage (not high for a diesel, may be high for small Honda though), you might be needing the glow plugs.

Test by removing the appropriate temperature switch/sender lead when the problem recurs.... just don't leave it off as it will probably be used for other controls.

To properly analyze a problem like this, we need to first understand what it takes for a diesel engine to run. In the case of a diesel, which is a compression ignition engine, it takes the proper heat in the combustion chamber, & the correct amount of fuel injected into the combustion chamber at the correct time for combustion to happen, thus the engine to start & run. A combustion chamber pressure of 700 degrees F needs to be attained. Start with a compression test & compare the results with service information. What most likely is happening is that the compression is a little low, which is causing the no start problem, & by waiting the hour and a half to two hours, lets the engine cool down enough to get the glow plugs to turn on, which will create the needed combustion chamber heat to get the engine started. I have also seen fuel injection pumps that were badly worn cause this same problem. In the case of the pump being worn out, the cause is not enough fuel injected when the engine is hot. The diesel fuel gets hot, & is thinner than cold fuel & the injection pump will not pump the hot fuel at cranking speeds.

AS the other two members have stated, it could be non functioning glow plugs at a time when your engine would like to have them working. You should be able to test the glow plug operation by connecting a test light to the power lead of one of them. If the test light coincides with the easy starting of tour car, you will know why it will not start. To repair it, you could try a temp sensor with a higher temp setting. That would allow the glow plugs to heat up at a higher engine temperature. Do NOT do this if the sensor is used to supply information to the engine computer. Another possibility is to use a separate dash mounted switch to energise the plow plug relay. Good luck.

GA for a great answer.

possible heat soaked starter? you did not say if crank speed was normal or slow when hot

Honda made Civics with diesel?

Wow over 1000000 miles!

I think it has paid for it's self a few times over! Pull the plates and get another! LOL

Sounds like a fuel problem. Diesels are relatively simple engines by design in that you only need proper fuel/air/compression ratios. Does it continue to run when hot? If so you can assume air flow and compression are ok. Is the problem only when you turn it off while hot? Don't think its the glow plug because that is only needed for cold engines to heat up the intake air. Your fuel lines could be getting too hot and creating a "vapor lock" or air bubble when you shut the engine down. A worn fuel pump may not be able to overcome this. As long as engine is running, fuel will continue to circulate but as soon as you shut down you get no more circulation. Are there any missing heat shields on your fuel rail? Maybe your problem is just a bad fuel filter. Thats cheap enough to replace but I personally would look towards too much heat going where it shouldn't be. Good luck!

Good morning, All,

I know absolutely nothing about diesels, so this may not remotely apply, but here goes:

I had a similar no-starting problem on my 2001 Saturn. After driving long enough to get the engine warm, if I parked for more than a couple of minutes the vehicle would turn over but not start. After 20-30 minutes, it'd start like nothing had ever been wrong.

After Googling and doing some research, I discovered that the crankshaft (or camshaft, I forget which) position sensor was bad. When I parked, the residual engine heat would begin to build and eventually reach a point where the sensor dropped out. Once the peak was past and the temperature started to drop, it would reach a point where the sensor came back to life.

Hope this helps!

Logan

The OBD II system should detect a crank or cam sensor that fails this way. If the car has no codes set, it should not be a sensor. Ford's 7.3 diesels had a rash of bad can sensors for a few years.