Alright.... 1994 Honda Civic EX 1.6l. Starts mostly when it is cold. I can get it started and it runs perfect. If I drive it or let it sit and idle for 20 minutes or so, and then wait 15 minutes(like going into a store), it won't start back up. It sounds like the engine is flooding and struggling to get going all the way. I've been working on this thing for weeks now putting in through different tests and then trying again, but the result is the same every time. Below is a list of what I have done:

Checked for spark - had it
Changed spark plugs
Changed dizzy cap
Changed ignition coil
Cleaned IACV
Cleaned FITV
Performed compression check - 155 across the board
Fuel pump does prime
Main relay does click


A couple of notes: I have not done a leak down check, but did find that fuel pressure was there when fuel rail was disconnected. Also, after the longer drives and no start I did find some moisture (I don't want to say fluid because it is not pooling) in the cylinders. Also, at that point of restarting when the engine is hot the spark plugs are fouled with fuel when I pull them out. Again, I have spark. I am a little lost on this and have been working on it for a while. Car is awesome and has only 180k original miles. I don't want to let this thing go for something I think should be easy to discover. What am I missing? What am I not seeing? Thank you in advance.

 

When was the last time the fuel filter was changed?

Have the injectors ever been cleaned?

 

Assuming the CEL works, have you pulled the CEL codes?

When the engine WILL NOT START, have you checked for spark and for the fuel pump priming?

 

Fuel filter changed in March. Spark is there during starting. Injectors never pulled and cleaned, but I do run seafoam regularly.

 

No CEL light illuminated. Have not checked for stored codes. Fuel pump does prime. Main relay does click.

 

Did you mean cranking^ rather than starting (because if the engine starts the spark test is invalidated)?

Does the CEL work?

 

Sure sounds like a head gasket coolant leak that starts when the engine gets hot and continues after the engine is shut off because the engine remains hot for a while.

 

Yes, I do mean cranking. Spark is always there. CEL does work. Honestly, I am leaning toward the head gasket, as well. My intention on posting was to make sure I wasn't missing anything before I pulled the head out. I appreciate all the help. Unless anyone sees anything else I may he missing I'll change the head gasket in a week or so.

 

Highly unlikely given the solid compression numbers. What specific type of fluid are you seeing in the cylinders? Is it fuel? White smoke in exhaust?

Check whether unplugging the primary O2 prevents the problem.

 

I had this exact problem in my 93 accord. Check your ECT sensor. There is a test for it.. Mine was reading infinite. It is a thermister. As the engine heats up the resistance goes down. Mine stayed at infinite. In my case the ecu thought the engine was cold. So it was sending too much fuel and flooding the engine. If you disconnect the fuel line to the rail. Get a small bucket to catch the fuel. I bet you it starts. Another thing to try is jump the pins in the ect sensor connector. By jumping it the ecu will send less fuel to the engine and it should start. Good luck.

 

Worthwhile^

 

x2. If head gasket leaking, wouldn't the plugs look really clean?

 

I think what i posted will fix your problem. Hopefully you'll let us know if does it.

 

I did fail to mention that I have already replaced the ECT. I have also tried starting with the O2 sensor unplugged, which was also replaced around March. I was curious about the inlet temperature sensor, but have not done anything with that. The head gasket was replaced about 5000 miles ago and did not have any of these problems prior to that, though.

 

I can't really tell what the fluid is. The plugs always smell like fuel, but one time I stuck a long q-tip through the spark plug hole and it looked like oil and did not smell like fuel. That was the only time I felt that it wasn't fuel. Again, I have pulled the fuel rail and primed the system and did not have any fuel leaking out. I thought it may have been a leaking injector for a while, but strayed away from that idea after not having the cylinder flooded with fuel...

 

Can you jump the ECT connector? Or put a meter on it and measure the resistance? I replaced my head for coolant issues. We used the ECT sensor from the replacement head and it was bad as well. Something to consider. Your issues are so similar to what i went through. The ECT has a big roll in the system.

 

I haven't jumped the ECT connector..... it has done the same thing with the old sensor, as well as a new sensor, though.... are you suggesting it could be the wiring to that sensor somehow?

 

Since you have one sensor off the car, you can test it cold with a meter. It will have a high resistance. Put it in some hot water and see if the resistance drops.

 

Interesting. I will check it out when I have some time tomorrow.

 

Post a pict of the ECT connector and its wire colors.

You can also try unplugging the ECT sensor, similar to the test I suggested for the O2 sensor.

 

I was able to check fuel pressure with a gauge. It was useful knowing the fuel pump was providing sufficient pressure. I had to replace my ECT connector because it broke when I tried to remove it.

 

Possible the splice came apart? And I have heard of people buying new components only find out they are bad...

 

My car is fine. Just wondering about the original poster. If his wires are messed up on the ect. It may show an open which could cause the car to flood.

 

Sorry I misunderstood!
Hopefully the OP will keep us updated.

 

All wiring looked good. Took the head off today. There was definitely a "moisture" in the cylinders and the rubber-ish coating on the head gasket pretty much came off the gasket and stayed on the head. I'm going to replace all the gaskets, hopefully Thursday, and put it back together and see where I'm at.