Hi I have a 94 honda civic, ex coupe, with a stock vtec engine with 230,000 miles on it. Im here because 4 months ago i started to have hot start problem. I'll drive 7 miles to the store and come back out and my car will crank but wont start. About 1/4 times the car will start but it barely starts up and idles very low, also when i give it gas the car wants to die out, as if im flooding it. I'v tried the gas pedal to the floor to shut off the fuel injectors and still no start. When no start problem occurs I'm getting spark and I'm also getting fuel pressure after the fuel filter. When the car is cold it starts up fine and idles normal.

Right before this hot start problem happened i had a overheating problem that is now fixed. Im getting a code 6 which is engine coolant sensor. Iv already replaced the sensor that works the fan with a used one and the fan turns on when supposed to and the gauge on the dash works also. ( not sure if this code or the passed overheating problem has to do with the hot start problem because my car started fine last summer )

List of parts iv replaced:
Distributor
Main Relay
Fan Switch Sensor
and did a General Tune Up

Please help me this problem is driving me crazy.

 

The ECT sensor could be causing this, fooling the ECU into thinking the engine is very cold when it is actually very hot, may not start or run well. So since you're getting a code, try a new or used sensor. This sensor is screwed into the head underneath the distributor, it is the one with two wires.

Also I'd check the MAP sensor with a voltmeter, readings with the engine not running (about 3.5 volts I think) should agree whether working normally or not starting.

 

Ok Ill go up to the junk yard and get a used ECT sensor there tomorrow. also when my car has the hot start problem, Iv d/c the battery to reset the ECU but im guessing when i try to start it again if the ECT is bad it would read the engine as being cold still.

I checked the wire going to the MAP sensor and got like you said 3.5. Not sure how to test the actual sensor?

 

When it will not start, check the MAP voltage again and make sure it's still 3.5. The voltage should drop with the engine running because the pressure in the intake goes toward vacuum then.

 

u had an overheating problem before. i dnt wanna take u so far yet but since they already told u to check map and ect sensors... u shud also chek for blown head gasket. it starts wen cold but once u run it ur gettin either water or oil into the combustion chamber, so its hard to start wen hot

 

i forgot to mention, i had the same problem. i overheated my car. same sympthoms. it wud be hard to start once it was hot.. i had a blown head gasket

 

there wasnt any water or smoke coming out of the exhaust and iv changed my oil sense the overheating problem and its the normal consistency. Also no water drips on the dip stick. Im going to change the ECT and report back

 

Ok, I replaced that sensor and the ECU light went out and has stayed out. Now for the starting problem, I haven't been in the situation where I have to start my car after 5 min of turning it off. But just today i went to start it after 30 of running and it started up fine but idled very low. around 300 and less rpm. At a stop light i had to put it in neutral and give it gas just to keep it from cutting of it seemed.

EDIT: Today i drove to the mall which its 10 miles away, waited 5 min and tried to restart it and my car started up fine. 6 hours later drove back home and stoped at gas station, turned car off and it started up fine (but still a very low idle and when i push on the gas the rpm goes down before the car speeds up). Drove home and it started up fine 10 min. after turning the car off. So I my problem now is the low idle. help please?

 

Ok? i guess no one is going to reply.

 

Idle problems, start by cleaning the IACV. Also air bubbles can cause inconsistent idling, check that the cooling system is completely full. Take the radiator cap off when the engine is cold and the radiator should be full to the top.