Truck Trouble again 2002 Chevy Silverado Any Mechcanics?

[TOOLMAN]

Hi guys
Anybody good with scan code readers and what to look for Ive tried everything and its getting crazy now
I have been getting a code well 2 codes saying that system to lean bank one and system to lean bank two
so therefore a lean condition exsist, I cleaned the throttle body and MAF changed the plugs and even have seafoam in gas (LOL).
each time I cleaned something the truck ran a lil better until I get a pop and hesitation on stepping on the gas then within a few mins the code pops up again (trouble light). I can reset it and run it until I step on gas and try to accelerate fast and bing then the hesitation comes back.
I also changed the fuel filter which had some blockage to it, and the TBS (throttle body sensor Too)
OK heres my question: anything I missed that could be causing this I am starting to lean towards the fuelpump because I see they have been having numerous problems with Chevy Fuel Pumps so anyone please chime in Thanks
Tony

[cubguy]

I say the fuel pump, Chevy is know for bad fuel pumps. The easyest way to change the fuel pumps is to take of the bed. Can do one in under a hour that way.
Kyle

[John *.?-!.* cub owner]

Had similar problems with Ford Aerostar when pulling a small camper. turned out to be a bad fuel pump. If you have a dependable dealer around check with them. My van was out of warranty, but Ford covered the fuel pump anyway.

[Mike A]

Bank one and bank two sound like Oxygen sensors. I just bought a 2002 K2500 with an after market exhaust and my trouble light comes on and off at will. Code reader reads lean at both sometimes, even though truck seems to run fine. More annoying than anything. Check underneath truck in front of your gas tank, my fuel pump is in a plastic box; not in the tank. Looks not too bad to change.

[Jack fowler]

Were you doing any engine work containing any RTV sealant? Have you fueled with any E-85 fuel? I guess you have a DTC(s) P0171 or P0174 set. Make sure the air intake (duct work) is tight from the throttle body to the air cleaner. If you have a scanner give me the data,maybe I can help. If not before you condemn the fuel pump,check the pressure output. Fuel pressure readings on the following engines: (8th digit on VIN label) (55-62 psi) VIN: (V, T,U) (48-54 psi) VIN: Z . I’ll be in and out all day so, if I can help any more drop me a line.

Jack

[TOOLMAN]

Jack HI again
I also wanted to ask you have you ever heard of headlights having to be reset in the computer by the dealer like a headlight on code or something Thanks Now on to the next problem.
You hit it those are the codes
The intake and MAF are super clean and sealed and no RTV
did clean the throttle body out and replaced the throttle sensor
Have not cleaned the EGR thats next.
It all started with when my auto start stopped working and it became a hard start never on 1st turn of the key anymore always the second somethings third try.
I did just replace the fuel filter yesterday in fact and it did have some blockage but not total was hard to blow through(the old way) LOL.
I have not checked the fuel rail pressure yet but when I had my autotap system working last week it said about 35lbs I believe
It is a 4.8 V in the vin.
I never did get them dang headlights to work only way was to re ground them (could this be a result of me grounding a headlight wire Ihope not)
My neighbors and ET and he said it should be no problem.
Thanks for all the help on the lights too!

[Jack fowler]

You stated you checked the fuel pressure and it was 35 LBS. To low for a 4.8 L. and that will set a lean DTC. Anytime you start messing around with wiring you could very well spike something in the electronics of the vehicle. I don’t think that’s the case this time, since the engine problem didn’t start until later. Follow this Doc for fuel diag.
http://docs.google.com/Doc?id=dcpqrttm_228cb5mvsdg

Your headlight system does not use the Body Control Module (BCM) when headlight switch is turn to headlamps position. When switched to “Auto” it does.

As far as resetting the computer, the only module used on the circuit is the BCM and like I said it is not used on manual operation. You do have “logic locks” on modules and yes you have to reset them sometimes. If a reset is needed I know of a way to do it without the use of a scan tool and you can do yourself.
Review this doc. For the headlights
http://docs.google.com/Doc?id=dcpqrttm_199c4gvr9

Hope this helps. Any questions or help just ask. I have to leave for awhile, but should be back later tonight.

Jack

[TOOLMAN]

OK heres the story
It all started when I noticed that my auto start stopped working and failed to turn over the engine by the third try. Then the truck started to bogg down on acceleration from a stop step on gas and it started to pop pop and then catch and throttle up but not normal seems like its struggling to do so,also the tranny seems like it is not switching gears as it should on acceleration.
So the genius in me said ahha a tune up time so I changed the plugs but not the wires only 45,000 on motor plugs in are suppose to be good for 100,000 The old plugs looked like they were burning very clean and good spark not bad at all almost put them back in.
I used AC Delco Platnium plugs as replacements
I then check motor still throughing codes 1071 1074 Lean System
So I cleaned the MAF sensor cleaned code and accelerated fast engine Pop Pop inside what sounded like throttle body and trouble light came on on next start up.
I then clened Throttle body changed throttle sensor and have since cleaned the EGR valve since its right there on TB too.
I reset the codes and it was good until I hit the gas and Pop pop again the next start light comes on.
So this time I scanned it and came up with the following codes

Fuel system 1 CL using H025
Fuel System 2 CL using H025
STFTRM1 % reading changes up and down around 16
LTRM1 % READING STAYS THE SAME AT 24.9
STFTRM2 % again reading up down around 16
LTFTRM2 AGAIN STAYS AT 24.9
RPM RIGHT AROUND 600
IGN ADV IDLE 15-19
IAT 57
MAF 10.115
02S11 .07-.765 Changes 15-18 %
02S12 .850 NO CHANGE N/A
02S21 .115 - .83 CHANGES 14-16 %
02S22 .830 N0 CHANGE ALSO N/A
PTO NOT ACTIVE
So there we have it if these mean anything feel fun to say so THanks
I thinking an O2 sensor but not sure which one.


Thanks Tony

[Joe Malinowski]

I had a bad fuel pressure sensor acted like your talking about it was a dealer repair to the tune of like $175.00. I have a 01 GMC.

[TOOLMAN]

Joe Thanks But I forgot to include that on my list
That was the 1st thing I replaced I even just went back out and reinstalled the old one just in case I got a bad new one
No such luck still the same
Thanks Tony
I think it has something to do with the MIL codes not sure Im reading them right

[Harold R]

My 2001 Z71 had some of the symptoms you are describing. After 3 trips to the dealer......some young guy came walking through the garage area from the toyota department and said it was the wiring bundle in the steering column. I chuckled at him........but turns out.....that's what it was. Said a bad batch or two had come from the factory in Mexico.

[TOOLMAN]

yes i did here that the ingnition switches go bad and that is a wire bundle in steering colum prob one in the same

[Jack fowler]

This is what I see:

Bank 2 sensor 1 (right side first sensor past the exhaust manifold) shows lean at .115 volts. How long does it stay at that data? The PCM is trying to compensate by adding fuel shown by the STFTRM1 and STFTRM2 (Short term fuel trim rate monitor 1 and 2). The 02 sensor(s) are working OK as for as I’m concerned. Left side 02S11 .07-.765 is reading a little on the rich side. Usually when a G.M. sensor fails they will stay constant. What I see now is a fuel injector / vacuum leak ect. issue on the right bank.

Is the engine running smooth at idle? Clogged Fuel injector issues have been somewhat of a problem, but usually with a rough running engine. No alcohol or foreign type fuel in the tank…right???

What should be done, you should snap shot the data when the engine acts up. That will let me see more of what’s happening. If your scanner does not have a snap shot capability, use a camera or have someone write the data down.

As you said; you thought the fuel pump pressure was 35 lbs. 35 lbs is to low for that vehicle. Recheck fuel pressure as I wrote in the fuel diagnosis document to determine, if you have a fuel pump or a fuel pump regulator problem. http://docs.google.com/Doc?id=dcpqrttm_228cb5mvsdg

Let me know what you come up with.

Jack

[Jack fowler]

Tony,

I sent you another PM. For some reason it didn't go the first time,so I sent it again.

Jack

[TOOLMAN]

OK
2002 Silverado has no pressure with key in on position 0 reading
But truck starts on 2nd turn of key and then pressure reads 21 lbs. I changed the fuel filter and pressure switch last week no inprovement. What ya think guys time for new fuel pump?