Hi, I have been reading questions and answers on your website and have a couple of questions myself. I have a Jeep Liberty. 2 days ago it would crank up but was running rough, white smoke coming out of tailpipe. I shut the car off and when I cranked it later it ran fine but the check engine light was on.
Yesterday it cranked and ran fine but when I went back out to leave my office it would crank but kept cutting off every time I took my foot off of the gas. Any suggestions on what it could be?
I would first want to read your computer codes and see why the light came on, I would suspect it is a “loss of crankshaft signal” type of code. These vehicles are prone to crankshaft position sensor failures, which can cause “no start” situations like you mentioned. Lack of fuel pressure from the fuel pump to the engine can also be a culprit.
Hopefully the smoke you see is due to the starting problem and too much, or too little fuel in the cylinder and not something more serious like a head gasket leaking problem.
So, honestly, I would pay a mechanic to diagnose this for you, guessing at this is going to cost a lot more money.
Things I would look at if you were in my shop.
1. Read computer codes
2. Check crankshaft sensor
3. Check fuel pressure at the engine
4. Check and clean the throttle body on the engine
5. Check for a vacuum leak under the hood, like at the air filter cleaner box – oil change places like to leave them lose after inspecting the air filter.
Below is my video on cleaning the throttle body should you want to try something simple yourself and see what happens.
Let me know what you find out, and I can try to assist further once we have more info.