Hi Everyone,


I've got a few questions on some codes I've pulled from my 1999 Olds Bravada with a 4.3 V6 engine and 145k miles. But first, I'd like to share the kind of code reader I'm using (God, I love this thing...) It'* a:


Actron model CP9580 AutoScanner Plus


I've gotten the following codes:


U1000 - Class 2 Data Link Malfunction
P0171 - Bank 1 System Too Lean
P0174 - Bank 2 System Too Lean


I would really like to know why that first one keeps coming up...is it because there is something lacking in the scanner?


Regarding the lean bank conditions, I understand it could be bad 02 sensors (in my opinion, not likely to both fail at once,) a vacuum leak from the engine air intake (more likely,) or perhaps low fuel pressure (clogged lines, or bad fuel pump, but not fuel filter, as I just changed it. I also put some SeaFoam into the gas tank to clean out the injectors...but don't know if that'* enough to clean possibly original injectors. I also use Chevron with Techron, but that'* just me - I don't know what the previous owner used.)


Knowing all this that I've written here, would anyone have any of the MORE LIKELY causes in Bravada'* for matching lean banks 1 and 2 codes to come up? I'm just trying to see if there'* a little better order of troubleshooting for me to proceed. Here'* one troubleshooting guide I found that seems to be pretty solid!




It just so happened that I had the EXACT same scanner they did


As always, many, many thanks for taking the time to respond!


Regards,


Maitai

I couldn't find an edit button, so I'm quick replying to inform you that the Led Zeppelin Kennedy Center Honors was NOT the link I intended to post! Just imagine what it COULD HAVE BEEN!!! : / Here is the CORRECT link to the troubleshooting page I originally wanted to link to:


Part 1 -Troubleshooting P0171 and P0174 (GM 4.3L, 5.0L, 5.7L)


Enjoy both

And, to round this out, I did probably leave out some pertinent information. My Bravada starts like a CHAMP in cold weather after sitting overnight - going to work is a BREEZE. However, I'm having hard-starting conditions when the car is warm, as in making multiple short trips. Sometimes, it takes a dozen turnovers total with breaks in between. I keep my foot off, pump, hold the accelerator to the floor - I'm just not sure what works. However - on a hunch, I'm hoping that whatever is causing my lean condition will resolve these warm hard starts once I find the problem. LAST POST, I'm sorry to have mucked this one up! Best, Maitai

Check your fuel pressure with a gauge. Your pump may be dying a slow death instead of just immediately failing. Another possibility is a bad fuel pressure regulator. That troubleshooting link is quite good by the way.

Good thing it wasn't a **** link. LMAO

Actually, I enjoyed the video.......I was a Zepper!

Great! Sorry haha..

Yeah, that wasn't lost on me, especially since it seems I can't edit my posts ahahaha!

Hey Coachman,


Here are the results of my Schrader Valve testing:


Pressure key on: 60
Pressure key on, then wait: About 50-51


Pressure engine running: 63, then a drop down to I think 57


Sorry, I've been meaning to reply, and these are by memory...I will correct them on Saturday, but I think they're close.

How do we test the pressure regulator since it'* not immediately accessible?


Many thanks Mad_Coachman, I really appreciate the help.


I still have these conditions:


Cold - Starts like a champ!
Cold engine, warm weather - a dozen turnovers sometimes
Warm engine - a dozen turnovers sometimes


Kind regards,


Maitai

On my 3.8 liter engine the FPR is on the fuel rail right near the schraeder valve where you check the fuel pressure. I am not familiar with the 4.3 but hopefully someone else can tell you where it is on that engine.