Car won't start after warming up

[bToTheM]

There is a strange issue that has started happening to my car (93 240sx DOHC). When I drive for more than 20 -30 minutes and then turn it off, it won't start again. I can hear it turning over, and it starts to smell like gas. I can still get it going with a push start, but not a jump start. If I leave it for like 3-4 hours it will then start again perfectly.

Also, after driving for 40+ minutes, if you try to rev the engine from idle it will stall a bit (or sometimes completely). If I keep the revs up though there is no problem.

I have had the battery tested and charged, and I replaced the terminal connectors since the old ones were corroded pretty badly. I am thinking it is maybe a fuel thing now or perhaps a faulty sensor? Any ideas?

[vancouverbc]

How old is starter? I would connect starter directly to battery to see if you have a marginal interlock relay. Point 3 in my tutorial.

zerothread?id=249966

[vancouverbc]

zerothread/160219

or this maybe

[bToTheM]

I dont think it is the starter since I can hear it cranking. I am going through that hard start list today and will let you know what I find. Thanks.

[240sxvaj]

i had the same problem too a long time ago. check your ignition coil.......

[sideways24d]

I have the same problem. I changed the coil ,transistor ,and the cap n rotor and I still have the same problem. really blows . Is it intermittent?

[jdm_master_X]

im inclined to believe its your coolant temperature sensor.

my reasons are: -you smell tons of gas when you try to start. the computer is trying to richen the mixture as if the car were cold. -its running rich because the computer believes the car is still cold.-your car starts up after a few hours because its cooled off.

when a coolant temp sensor is shorted, it mimics the highest temp available to the computer. when open, it assumes the temp is below -40ºF.

[sideways24d]

So when the car heats it shorts out? The temp gauge never reads hot and I know it functions properly.

[vancouverbc]

So when the car heats it shorts out? The temp gauge never reads hot and I know it functions properly.

temp gauge has its own sensor. he is talking about the sensor with red plug that sends information to ecu.

[sideways24d]

would that cause a stall?......only when its hot?

[vancouverbc]

temp sensor is really easy to test with multimeter.

Temperature Sensor Checking the ECU’s Water Temperature Sensor:

David Balingit <[email protected]> writes:

There are two water temp sensors. One goes to the ECU and one goes to the temp gauge. The sensor with the F.I. type connector is the one you need to look at. (It’s the LEFT one of the 2- as you look over the radiator at the engine.)

I wish I had my manual in front of me, because then I could tell you the normal resistance vs. temperature. (Heheh! We’ll help ya’ out here Dave! :-) A&W)

Temperature Deg. F. Resistance k Ohms 68122176 2.1 - 2.90.68 - 1.000.30 - 0.33

You need to have an ohmmeter to measure across the sensor (with the connector removed). Check the connections too.... if the connector is all gooked up and corroded, this could cause higher readings to the ECU and give more fuel dump.

If you end up removing the sensor, don't forget to bleed the cooling system.Sensors are free if you have a buddy with just about any type of late modelNissan, just don't tell them you swapped them 8-).....

Everyone should remember that the water temp sensor is just a starting place..... it's just one of 30 things that could go wrong with E.F.I. systems (bad MAF, leaky injectors, corroded connectors, idle switch, bad TPS, etc....) I think every back-yard (or carport) mechanic needs a real shop manual and a multimeter to easily diagnose most F.I. problems.