Car Starting Trouble Cold Start Need Some HELP

[Matrixhunter]

Hey i just replaced the transmission put everything back together . Couldnt get car to start figured it was because it was sitting for two weeks. THen me and friend managed to get it to start but inorder to start it he had to play with the throttle while i was starting the car. Idled amazing after ok so we let it. Started again perfectly find 20 min later so we thought its ok. Get up in the morning today same thing cant get car to start. It seems like not enough fuel i getting to engine or something or air/gas mixture totally off. I just replaced o2 sensor to would that have anything to do with it check engine light is on but its a brand new bosch sensor. Or is it something simply to do with the choke. I dont know what it could be took it to the mechanic just dont trust them. Going to try a sell me new engine

Any ideas what could be causing the hard start up ? any help would be good.
Keep in mind starts good when warm idles perfectly steady at 800rpm. Thanks

 

[GSXTuner]

how long has it been since you changed your plugs? make sure they are gapped good.. if they are old and have a big gap then it will have a real hard time starting when its cold..

 

[Old Mitsu Tech]

If it starts ok when hot and very hard to start when cold, I would highly suspicion the coolant temp sensor. This is the new version of carburetor chokes. If the engine is cold and the sensor is out of calibration and says the engine is warm, the pcm which is stupid will set the fuel to a warm engine.


Good Luck

 

[98GST6BOLT]

im having the same problem, it dont wanna start when cold but fine when starting when warmer in the afternoon. its prob the temp sensor on the thermostat housing, ive gotta do the same thing to mine, or maybe you have to buy a new one.

 

[cesarmaz]

Does anyone have another idea ?? i have 2 eclipses GST 2G.

One of them i bought from a collector, it has only 23k miles, everything original, a perfect car, like brand new. Some weeks ago i have this cold start issue, 4 or 5 times cranking.

I have dsmlink on both cars.

- I´ve already changed plugs, checked wires.

- I checked the coolant temp sensor, when pluged shows 27ºC when unpluged shows -40ºC on dsmlink, and when car is hot shows around 90ºC, so my sensor is fine.

- Changed the fuel pump, checked the fuel pressure regulator on the rail.

- Changed my injectors from 450cc to 550cc and ajusted that on dsmlink, then injectors is not the problem too.

- Removed the ISC, tested all coils, everything fine (around 30ohms).

- I logged the MAF on dsmlink, seems to be perfect too.

Another good thing from dsmlink is that my fuel pump starts when key is on, then when i crank i already have full pressure from pump available.

When hot, idle is perfect, car runs perfect and mileage is very good, only first start of the day is the problem.

I noticed one thing: When car is in idle, i unpluged the cam sensor and nothing happened, engine continue runing fine, then i put it back. When i unpluged the crank sensor, engine died.
Is it normal ?