Weird no start issue, turbo 2006 GT.

[freeloader1969]

I have a 2006 turbo charged GT, On3 system/6lbs of boost. The car currently won't start. Here's where the starting problem is weird. The car will start and run every few days if I pull out the spark plugs and clean them. The car will run great actually, making boost, burnouts, etc...However after I shut the car off, it won't start again after the engine goes cold and my spark plugs keep fouling on attempted restarts. If I hold my foot to the floor to do a "clear flood", the car sounds like it wants to start but very briefly, like not even for a second. I've checked the fuel pressure in the rails and I have 44 psi after a day, so I don't believe there's any leaking injectors. I'm pretty sure this is going to be some sort of electrical problem or a sensor problem. Any suggestions would be greatly appreciated.

 

[JeremyH]

Typical blow through maf cold start tune issue. Try unplugging the maf next time you try to cold start it. If it starts right up then you know for sure it's the tune adding to much fuel on cold start.

 

[freeloader1969]

Typical blow through maf cold start tune issue. Try unplugging the maf next time you try to cold start it. If it starts right up then you know for sure it's the tune adding to much fuel on cold start.

Thanks for the advice. I will try that tomorrow and let you know what's happening.

 

[stv_huff]

Do you have a log file to look at?

 

[freeloader1969]

Do you have a log file to look at?

I can certainly make one. BTW...same problem today. No start again. What sensors should I log? I have a SCT X4.

 

[freeloader1969]

Waiting on new plugs now. For reference, here's some of the plugs that came out of the engine.

 

[freeloader1969]

Typical blow through maf cold start tune issue. Try unplugging the maf next time you try to cold start it. If it starts right up then you know for sure it's the tune adding to much fuel on cold start.

Tried what you said. No start.

 

[JeremyH]

Tried what you said. No start.

Try holding pedal to floor with maf unplugged as you start as well. But looking at your plugs car is definitely running rich. Also how is your pcv setup looks like may have some oil dilution as well. Also pop a bottom coupler off the intercooler and look for oil. Look for oil on maf sensor as well.

 

[Juice]

Try holding pedal to floor with maf unplugged as you start as well. But looking at your plugs car is definitely running rich. Also how is your pcv setup looks like may have some oil dilution as well. Also pop a bottom coupler off the intercooler and look for oil. Look for oil on maf sensor as well.

View attachment 72316

That photo is wrong. White=Lean, Brown=Good, Black=too much fuel/rich

 

[JeremyH]

That photo is wrong. White=Lean, Brown=Good, Black=too much fuel/rich

Huh? That's what the photo shows lol
Sure the leaner you are the more white you get. But you get the idea just first pic I grabbed off google.

 

[Juice]

The one on the left is marked LEAN. That plug is brown, brown is GOOD. The two outside plugs are labeled backwards.

 

[JeremyH]

The one on the left is marked LEAN. That plug is brown, brown is GOOD. The two outside plugs are labeled backwards.

I can see what ya mean. Didnt look that close here is a better google pic.

 

[Juice]

That one is correct!

 

[JeremyH]

Op's are def under rich or oil issue as mentioned.

 

[freeloader1969]

Had it running last night. I cleaned all the engine bay grounds today. Can a faulty ignition switch cause a no start/start condition? It works one day and not the next kind of thing. Also, while cranking the car I noticed the voltage drop to 10.5 volts, measured at the battery. Can't get the battery tested due to Covid restrictions right now. The car has 130K on it, so probably the original switch. The car will always crank however, just won't start. I'm going to take a video of the car cranking though my X4 later today and post it. I don't know if that will help anyone come up with a diagnosis, but I sure can use an act of God right now to keep this thing running. BTW...no codes are stored or thrown during the no start or even when the car does run.

 

[Dino Dino Bambino]

As far as I can see (said the blind man ) your battery has plenty of juice, and a faulty ignition switch would cause a no crank situation. Since your engine does crank (and quite strongly too), that rules out the ignition switch right away.
Pull the plugs and see if they smell of fuel after you've cranked the engine over. That might help point you in the right direction to troubleshoot the problem.

 

[freeloader1969]

As far as I can see (said the blind man ) your battery has plenty of juice, and a faulty ignition switch would cause a no crank situation. Since your engine does crank (and quite strongly too), that rules out the ignition switch right away.
Pull the plugs and see if they smell of fuel after you've cranked the engine over. That might help point you in the right direction to troubleshoot the problem.

The plugs are fouled. Has to be a tuning issue or PCM problem now. I can't think of anything else.

 

[freeloader1969]

Follow up for anyone wondering what was wrong, it was the PCM. Put a used PCM in it, programmed it and the car fired right over. Thanks for everyone's help.