Wont start when warm

[badabing33a]

Ok so if i start my car up in the morning or after it has sat for a good 4 or 5 hours, the engine spits and spudders for like 2 seconds. then when i drive it, it will spit a little until it has warmed up a little. if i drive the car for like an hour or two, then turn it off when i get gas or whatever, it wont start up. This other day, i sat for 3 hours waiting for it to start. it just cranks over and over and does not start until cool. also, while i am trying to start the car after running it, it smells like bad gas or starting fluid. im thinking this has to be fuel related so i will swap out the fuel filter to start off. this really sucks and i want it fixed. any ideas on what it could be? also, since i bought this car i havent done anythingto it besides installing NGK Plug wires. Its always had this problem but is getting worse. For example, the hotter the day is, the more common this is.

Oh and the car smokes a little bit at startup or when im stopped in the McDonalds drive through etc.

 

[nyTalonTsi]

Most of the time, the coolant temp. sensor is going or its the fuel pressure solenoid thats there for hot starts.

 

[talon187]

coolant temp snensor

 

[badabing33a]

Can i swap them out with one from one of my 3 other DSM's? Is it easy?

 

[nyTalonTsi]

Yeah the CTS is simple. And so is the fps.

 

[badabing33a]

i changed the coolant temp sesnor. still didnt do anything. where is the fps located?

 

[badabing33a]

I have been searching and searching and cant find the FPS. I am going to change the fuel filter to see if that helps. I have 391 page thing about 1G's i downloaded from this site and i cannot find the FPS.

 

[misphit]

The fps is the fuel pressure solenoid. It's located on the firewall, driver side. Follow the vacuum line from the fuel pressure regulator on the end of the fuel rail.

 

[badabing33a]

The fps is the fuel pressure solenoid. It's located on the firewall, driver side. Follow the vacuum line from the fuel pressure regulator on the end of the fuel rail.

Ok thanks man.

 

[steve]

First are you sure you changed the right coolant sensor? The Engine Coolant Sensor is the two pronged one in the bottom of the thermostat housing. Even if you changed it you may have a wiring problem so you need to check with a datalogger that it's reporting good data or measure everything with a multimeter.

The Fuel Pressure Solenoid (FPS) functionally sits between the intake manifold and the fuel pressure regulator. Normally the fuel pressure regulator sees the vacuum in the manifold (or boost on a turbo car) and adjust the fuel pressure to track the changes. The FPS is a switch. It either connects the FPR to the intake manifold or to atmospheric pressure. On hot starts the ECU activates the FPS to connect the FPR to atmospheric pressure rather than the vacuum in the manifold causing the fuel pressure to rise and reduce the chance of vapor lock in the fuel lines/rail/injectors. Just connecting the FPR to the intake manifold will bypass the FPS.

 

[Empyrials]

i just spent well over a month troubleshooting an issue similar. i went through everything 3 times trying to fix my hot start issue, nothing worked. The Coolant temp sensor was reading fine on DSMlink, i tried 3 sensors, 1 new, one from a working car, and the used one i had.

I ended up just having to get a 2nd coolant temp sensor and just zip tie it down and plug the sensor to that sensor. So it always reads whatever the temp is under the hood but no big deal. My car starts every time now. f'n wierd. In my mind it's not a good fix but i was out of options.

 

[badabing33a]

I need a picture or diagram of the FPS and FPR. The Coolant Temp Sensor i replaced was the one that goes into the thermostat housing. One end of it threads into the housing and the other is where the plug, plugs in to. If I zip tied it back, wouldnt coolant leak out like a mother F'er? . Oh wait...you mean having one thread into the housing and another plugged in and zipped tied up...ahhh. Imma try that ### it wont start right now. Just got home so ill hurry up before it cools down. But i dont want this to be perminant. Id like to find the real problem.

 

[steve]

The Coolant Temp Sensor i replaced was the one that goes into the thermostat housing.

All three of them go into the thermostat housing. There is one for the gauge, one for the AC and one for the ECU. So which did you replace?

 

[badabing33a]

The one that has a thing on the end that looks like...actually looks like the Water Temp gauges on the race cars to come to think of it. So it might be the wrong one.

 

[91AWDGSX1G]

I am some what having the same issue. I think it has to do with the fuel though. My car will start rev to 950 rpm sputtering for about 2 or 3 seconds die and then I hear the fuel pump kick off. Sometimes I think I hear the gas bulb in the tank??? I guess Ill try replacing the FPS. I need to get a AFPR since Im running the 255 and 550 injectors. Hope you find the problem!

 

[badabing33a]

I am some what having the same issue. I think it has to do with the fuel though. My car will start rev to 950 rpm sputtering for about 2 or 3 seconds die and then I hear the fuel pump kick off. Sometimes I think I hear the gas bulb in the tank??? I guess Ill try replacing the FPS. I need to get a AFPR since Im running the 255 and 550 injectors. Hope you find the problem!

Yes thatsexactly what mine does. I start it up, it hesitates, spits, spudders, etc and then dies. Can you smell something that smells like bad gas or starting fluid? Your windows have to be rolled all the way down though so you can smell it. I will let you know what you find out and please do the same.

I think i got the right Coolant Temp Sensor though. I used a 3/4" wrech to get it off. I put one in, then had another dangle down and the temp gaugue works fine so I think I did find the right one. I am going to try the FPS today. I may just bypass it.

 

[91AWDGSX1G]

I know your car is all stock, but I realize mine would do this when I keep resetting my ECU fuel trims. I have not restarted them for 4 days by removing the fuse and it starts up fine now. I am not sure If I can help you but you might try changing the FPS like they said.

Good Luck