If you guys have read my previous thread, I have been having problems on start up. At first I thought the fuel pump went out, so I changed it and the next day there were still problems. So I thought the fuel filter was clogged, so I changed that out and the next day still had the same problems. So last week I was heading home from my gf's house and my car would not turn over. So I mest with it for a couple hours,changing out the CTS and MAF (cause I had extras in my car) just to see if those were the problem. I checked the fuel pump again and it was fine. At one point it started up but shut down 10 secs later. It
did this about 6 times, but would not stay on for long. My mechanic thought that it might be a sensor that automatically shuts the car off. So I ended up getting it towed back to the shop (which was 40min away AHHHH!) and waited till this yesterday cause he did not have to computer part to test my car. So I called him up today, wondering if he found out what was wrong, and he begins to tell me that nothing was wrong. WTF!!!! He said the car started up fine and the computer showed nothing wrong. (Oh by the way this would be the second time I got it towed to his shop and the thing started right up, $150 in towing overall) So I told him to keep the car overnight and try it early tomorrow cause that seemed to be the prime time for the problem to show up. All of this took place a couple weeks ago and now my car has the EPC light on. So my question to you guys is, do you have any idea what is wrong with my car? Has this ever happened to anyone before?

 

you sure it doesnt have anything to do with your after run sensor? i have heard nothing but bad things about those? and also the mbc you have installed if that is up to far it is sending mixed signals to the ecu and that could be shutting it down...

 

try the throttle positioning sensor. My car's sensor was bad and made it run at 1500K at idle and the car wouldnt start.

 

Codes.?

 

mattr- I am pretty sure its not my after run sensor. I might go buy one just to make sure cause it is cheap but pretty sure its not. I switched out the sensor with my stock one to see if anything changed and nothing did. I will check the MBC, I have never heard of it messing up if its placed too high but it wont hurt to check. thanks for the advice!

drev- I will definitely check the throttle positioning sensor. Of the times it did start, the idle rpms were somewhat high but you shortly go down, i just thought it was normal cause they went down somewhat quickly.

HP Addict- right now I am at school, but I currently have a portable VAG recorder that records everything that goes on in the car (not sure of its actual name, but it records up to 135 start ups). My brother is going to take it to my mechanic tomorrow morning to see what it says. So hopefully it will show something cause during this entire ordeal, no codes have popped up which makes it harder to diagnose.

 

Check your ICM man, a friend of mine was having a similar problem, car would die randomly, problems starting, etc...the ICM was going bad so it would intermittently work perfectly (eg. starting up without any issue at the shop) and other times it would totally take a ****.

It may or may not be your problem, but it's worth looking in to.

 

check the crank sensor. My car would do that too where you would turn it on..and it would die after about 3 seconds

 

so its been awhile since i let you guys know what has been going on so here it is. First off, its still has the problem. I ended up taking all of your guys advice: I took off the MBC and replaced the ICM. I first replaced the $210 ICM which made no difference and took off the MBC which I thought actually fixed it, but just yesterday as I was about to head home from school, it didnt start, and still no codes. I will check the crank sensor next phitau09. Does anyone know where it is located or how much they cost? I am going to start looking around for some prices right now, but thankyou to every one that is trying to help. I promise I will buy dinner to anyone that can diagnose it correctly. I am just so sick of getting in my car and praying that it is going to start everyday. lol

 

forgot to add, the fuel pump is not turning on, which is why i think the engine isnt starting. is there a sensor that controls that?

 

Yes, its tied in with the all the other fuel stuff, start where you want and trace the lines and wires. Check all those PLUGS and sensors.

Problems as I see them
1. Very clogged fuel line (most unlikely but think about it)
2. Like I just said above with all fuel related stuff. (should lead you to something else if its not the origional prob)
3. Any major sensor has loosened and condensation has made it tempromental/ picky to work
4. Too much power to fuel pump and it keeps frying it. - check with volt meter

Let me know after this. I'm a mech of sorts not a mechanic a mech haha its different to me. I will think hard about this for ya.