1997 honda prelude, starts up fine when cold, when the engine is warm it struggles to fire up, idles low, dies

Question

engine starts up just fine in the morning before work, but if its been warmed up at all and i try to start the engine it will struggle to engage unless i feed it throttle, once engaged it wil idle very low, then die if im not feeding it fuel, after about 10-15 seconds it will idle fine.
also, my engine overheats if im not driving around, or, letting air cool her out.. i will overheat at stop lights.. just started happening, i changed the thermostat recently.. could it be fuel pump? filter? my plugs and caps are all good.
1997 honda prelude- 129k

Answer 1

The overheating is caused by the electric radiator fan that is not working. the fan is only used to pull air over the radiator when the car is stopped or at speeds lower than 30 mph. So the first thing to do is to find out why the fan isn't working and repair it. the fan could be seized and that would require a new fan motor. the temperature switch for the fan that senses engine temperature and turns the fan on could be open circuited in which case simply replacing the switch with a new one will fix it. Lastly, the fan relay may be bad.

the overheating is also responsible for the low idle and stalling. When you shut the car off, the high underhood temperature is causing the fuel in the fuel lines to the injectors to boil. The fuel vaporizes in the lines as the car sits. When you come back 10-20 minutes later and try to start it you are trying to inject vapor into the engine instead of fuel and the engine is running way too lean to operate as normal. By raising the engine speed up for 15 seconds you bring fresh fuel up from the fuel tank and then you'll start running normally again. This problem will go away after you fix the problem with the radiator fan.

hope that helps

Answer 2

> my engine overheats if im not driving around

Your electric fan is not going on. With any electrical system always check the fuse first. Then to check the fan motor, hot wire a 12V to your electrical fan and see if the motor is working. If the motor works, then get a volt meter (Radio Shack sell some very low priced) and see if the there's volt going to the electric fan motor (volt should go on an off with engine temperature). If there's no voltage to the motor, it could be the (a) wire (b) ECU (c) water temperature sensor. The water temp sensor should be easy and cheap to replace so try that next.

> then die if im not feeding it fuel,

Fuel injected engines have "ELECTRONIC AIR CONTROL VALVE" (EACV) that controls the idle. It should be at the mouth of the air intake. Some engines have a little screw you can turn to adjust the idle speed. Some cars have factory set idle speed and they cannot be changed.

http://www.autozone.com/az/cds/en_us/0900823d/80/0c/f1/a0/0900823d800cf1a0/repairInfoPages.htm

This web page is not specific to your car but maybe there enough diagram and information that you can extrapolate to your car.

Answer 3

i've got faith this is common for the duration of chilly climate starts. I even have questioned this myself and have not yet got here across an answer. My wager could be; a million) while that's chilly out, the engine oil is thicker and this is fluidity isn't as quickly as while the oil is heat. 2) Engine idle is controlled by using quite some sensors. Coclusion: while the sensors come across that the engine is chilly, in keeping with probability interior the process the IAT sensor, it deliver a command to the PCM to idle intense for about 30 seconds to a million minute as a manner to flow engine oil to necessary engine areas speedier as a manner to decrease bare steel to steel touch. (because of the fact the oil settles at thhe backside of the oil pan and thickens up for the duration of chilly climate.)

Answer 4

Make sure that your catalytic converter isnt blocked by taking it into a garage. If it is blocked then ask them to replace that section with a pipe. I say this because I had exactly the same thing happen to me almost exactly how you described it about 2 weeks ago. If it is not this.. Check 02 sensor or MAF sensor. Air filter. Oil filter - or switch for radiator fan. Hope this helps you!

Answer 5

check the oxygen sensor, coolant level and water pump, accessory belt, vacuum problem is another possibility.
get it running and spray water on vacuum lines from a spray bottle, see if there is any difference. Air flow sensor may be bad.Fuel filter possible but not likely.