cold start? - BMW Forum

enemigo · 07-03-2006, 06:11 AM

The engine wont start then cold, I must use starter for 10 or 15 seconds till it starts. What could be wrong? It starts fine when engine is hot.. Car : M3 '97 auto.

Furious · 07-04-2006, 07:32 PM

hmm, does it turn when its cold? or does it sound like its starving for fuel etc?

paco1076 · 07-05-2006, 12:29 PM

Does the car crank just not start? Or does it crank really slow (sounds like it is lumbering to turn the engine)? Usually a cold start issue on a gas motored vehicle is in the battery or charging system, but to help you more we need to know what it is doing. What does it sound like? Does it try to start, but doesn't? Does it not even crank over when you turn the key?

enemigo · 07-06-2006, 03:01 AM

yes, it sounds like like it's trying to start but does not start

battery is good, crank really fast.. After few tries it finally starts up, but it's like two or more cylinders are not working, engine shakes a lot, but after few more seconds it's everything fine-engine runs smooth. Spark plugs are new, I've made leakdown test its ~95% in all cylinders. So could it be ignition system or fuel delivery? Maybe its fuel pump? :/ It ussualy happens when I'm trying to start car in the morning, all day it starts and runs fine.. And the weather is not cold, about +25 degrees of celcius.. What should I check first? Thanks in advance.

Quote:

Originally Posted by paco1076

Does the car crank just not start? Or does it crank really slow (sounds like it is lumbering to turn the engine)? Usually a cold start issue on a gas motored vehicle is in the battery or charging system, but to help you more we need to know what it is doing. What does it sound like? Does it try to start, but doesn't? Does it not even crank over when you turn the key?

paco1076 · 07-06-2006, 07:29 AM

Sounds to me like a fuel problem. I would start with a new fuel filter and put some injector cleaner in your fuel tank. Make sure to run the highest octane fuel you can find for the next 2 tanks (the higher octane will help clean out the engine). After that, you are probably going to have to get a fuel pressure check done on the fuel pump. Also, try this... The next morning you get into your car, turn the key to on for 10 seconds before trying to start the car. This will allow the fuel pump to pressurize your fuel system before trying to start the car. If this helps, get your fuel pump and filter checked.

Good luck,
Paco

enemigo · 07-07-2006, 06:17 AM

thanks! But why everything is ok when the engine is warm? :/ If it's fuel filter the car should not start when warm also? Ok i'll try 10 seconds pause in the next morning and write what is happening.

Quote:

Originally Posted by paco1076

Sounds to me like a fuel problem. I would start with a new fuel filter and put some injector cleaner in your fuel tank. Make sure to run the highest octane fuel you can find for the next 2 tanks (the higher octane will help clean out the engine). After that, you are probably going to have to get a fuel pressure check done on the fuel pump. Also, try this... The next morning you get into your car, turn the key to on for 10 seconds before trying to start the car. This will allow the fuel pump to pressurize your fuel system before trying to start the car. If this helps, get your fuel pump and filter checked.

Good luck,
Paco

enemigo · 07-08-2006, 05:39 AM

the car didn't started even after 15 seconds ignintion on before start.. :/

polaris448 · 07-08-2006, 12:06 PM

my car turned over once and didn't start like you were saying for like 15-20 sec. it sounded like there was not any compression. this happened when i started it and turned it off when the air pump was on. it was like a valve was stuck open? then it started. never had that happen again. the shaking sounds like when it is too cold for the oil (10degrees F with 15w-40). i know you said it was like 75 out but just a thought.