97 yukon, stalls, hard start. VIDEO**

[God]

Video>watch please- http://youtu.be/iJstAiAlJlQ

In the video I'm in park and slowly easing on the pedal.

Hey my yukon is stalling on me a lot lately, I think it's the fuel pressure regulator because when it is going I can stomp on it and it's got a lot of power so I think the fuel pump is good. Dunno how to diagnose but I feel like the o2 sensor code it throws might be due to faulty fpr, also the hard starts. I have to prime the engine in the on position to get it to build enough pressure to start on less cranks. Thinking about buying the "new" Delphi injector assembly since it includes a new fpr. The only code it's been throwing is p0161- faulty downstream o2 sensor bank 2 sensor 2.

Also the strange thing about the stalls is I believe they are warmer weather related because this happened a couple times last summer and then over the winter I put about 2000 miles on and not one stall. Now that the weather has been 50+ I am stalling all the time and random dropoffs in the rpm. I don't know that this could be a computer thing or not. Also there will be times when my truck runs perfectly and the engine light will turn off. So how can I diagnose to be certain it's the fpr and I should buy the new injector kit? Money's kinda tight so I want to get what's broken fixed instead of throwing money at it.

Also the past Couple times I've had it running, if I leave it on in park running at idle it will just stall on me after a minute or 2 of running.

 

[Donnie Yukonie]

Could very well be the fuel spider , Just a FYI Ive heard loose caps on the distributor can cause this as well . the vibrations from the motor Jumps the loose cap off the rotor causing it to miss and cut off or catch it self like in your video . just something to check before you start throwing cash into it

 

[God]

Had fuel pressure tested. In the on position the fuel pressure goes to 60 then drops immediately to 0, and when it's running at idle it's steady at about 48. When you turn the engine off the pressure drops to 0 instead of slowly bleeding off. Mechanic that looked at it is convinced it's the fuel pump so I'm getting that replaced tomorrow.

 

[God]

So I replaced the fuel pump
And all was well for about a week. Today while i was driving te RPM's dropped to 0, recovered, and then it stalled on me as I was pulling to the side of the road. It was raining today if that makes a difference. What should
I be checking now? There's no check
Engine light and it restarts and idles fine.

 

[SunlitComet]

that is acting more like an an ignition drop off then a fuel pressure issue.

 

[God]

Ok ignition sounds good. What ignition parts should I check, and how do I check them?

 

[SunlitComet]

sounds good as it seems fine to you?

 

[God]

Sounds good as in good place to start.

I haven't been driving it too much but it still has random stalls, I think maybe more so after a rainy day. Some symptoms my yukon has that may or may not be related are: sometimes the voltage Meter on the dash bounces between 14 and 15 volts, after driving and putting truck into park the RPM's drop to 3-400 then recover to idle smooth. Most stalls lately have happened while coasting. Sometimes while driving RPM's drop to 0, then recover. Also sometimes it will only drop 50-100 RPM's while on the gas like it was a tiny hick up.

Has a new fuel pump and fuel filter. Idles at 49psi. No check engine light, always starts.

 

[SunlitComet]

49 at idle is not bad but look for readings under loads if you can as well.

 

[God]

Finally threw a code last time it stalled p0339- intermittent cps failure. Replaced the cps( which I spent over an hour looking for it's location) and so far it's running great. It would have been nice if yall forum tahoeyukon experts chimed in a long time ago suggesting a bad cps.