need help!!

[pjay]

hey yall how yall doin,ok my yukon awhile back would die on me while i would be drivin,its been sittin for a month now, iv been through 2 batteries an the past few weeks it would die right after i start it,i would have to hold the brake an give it gas to keep it running and today i started it and it stayed on but sounds like it wants to die and its also idleing lower than it use to,i appreciate the help
pjay

 

[blueflamed03]

Tps?

 

[Sweet_N_Low]

Start with basics. Fuel and fire make it run. Check for fire AT THE PLUGS. Check your fuel filter(s), then on to pump, then check carb/ injection system

 

[chip]

You sure it isn't the bearings?

 

[rich5368]

Sounds to me like either a IAC or a MAF. Try those.

 

[redemn93]

could also be fuel pump

 

[lowflyer]

yeah, before you start throwing money at it, check the basics.

Any check engine lights? Stick a scanner on it and a fuel pressure gauge. TPS voltage, IAC count and Fuel trim numbers are what you want to look at.

My money is on a weak fuel pump. The pressure ought be to above 50 psi for it to work well. If the pressure is OK at idle, torque the motor up and see if can keep up the pressure under load. If you have a gauge with a drain/bleeder fitting, see if it'll keep running while bleeding off some fuel into a container. I've seen fuel pumps have OK pressure, but very little volume. Looking at the Long Term Fuel Trim numbers will tell you if the PCM is trying to compensate for a weak fuel system. Any number over 10%-12% means the PCM is fueling the motor to keep it running.

EGR valve isn't stuck open is it?

Excessive exhaust back pressure from clogged cats will also cause your symptom, but thats kind of a long shot here...