white89gt

Agreed, an O2 sensor shouldn't cause it to stall. I was thinking you may have a vacuum leak, but that will generally shoot a code for a lean condition on one or both banks. I don't think it would be a bad idea to at least give cleaning your MAF a try... it could be the issue.

JR32

Yea, I'm about to go buy some MAF cleaner today. Was thinking about cleaning the throttle body and stuff as well. I need my truck tomorrow for work and was debating on just buying a new fuel regulator cause no one open today to test my fuel pressure and such. Do I need to depressurize my system before replacing it and if so what's the best way to do so anyone?

w0lvez

Try disconnecting the MAF sensor and do some test drive. If the engine is not stalling without the MAF sensor connected it's just a vacuum leak or dirty MAF sensor.

white89gt

The best way to depressurize the system is to pull the fuel pump relay while it is running, and let it die.

JR32

As of today, I replaced the fuel regulator, cleaned the MAF sensor and changed the air filter. I did what I could with the fuel pressure test. Truck stalled so couldn't drive test it.

My results:
At idle 30 psi.
At 2000 and 3000 rpms 30 psi.
Key on/Key off around 33-34 psi.2
When it almost stalled it shot to 40psi then back to 33-34 psi.
When it actually did stall out and didn't start back up it stayed at 33-34psi.
Been sitting for roughly 25 minutes and it's at 28-29psi.

white89gt

Just a couple of questions. Each time it stalls, is there anything that is common... such as hitting a bump, etc.? When it happens, does the motor just die? Or are you losing electrical power?

Also... just wondering if you have any loss of power? Have you had the catalytic converter checked to make sure it's not plugged? Maybe the code is telling you what's wrong.

JR32

It's random. I can be sitting in park idling and the rpms will drop and stall but sometimes the rpms will drop and go right back up and keep running. Also sometimes I'll notice the check engine go off right when the rpms drop. Driving or idling it does this but sometimes it runs fine for hours. Make any sense?

Never had the cat checked.

white89gt

I was just thinking.... if you have an infrared thermometer, you can actually check converter function by inlet and outlet temperatures. Let the truck come all the way up to temperature. Measure the temp at the inlet weld on the converter, and record it. This temp can vary greatly and be normal. Between 300 and 500 Fahrenheit is normal. Now check the temp at the outlet weld. You should be at about 125 to 150 degrees hotter than the front weld. If the temp is less.... that converter plugged and is bad.

white89gt

Well.... I'll be damned. I went to look for pics of which welds I was referring to above, and came across this thread. It has pics, and describes the same method I did... and more.

http://www.3geez.com/forum/3geez-acc...converter.html

JR32

I'll check into that. Funny I just seen one of those today, too. This truck is frustrating me lol.