Hans Myers

well, I was going over the pictures I took of the fuel trims over a few weeks. Bank 2 is consistently 3 points lower than bank 1 at all times. Just for the hell of it, I am going to switch injectors from bank 1 to bank 2, and vice versa. If I see that my trims change on each bank I will know if that is the issue.

I kinda doubt that since the fuel trims are fairly similar on both banks. Did a leak test and it held at 55 psi for a good 20 mins. Possibly a bad pcv system? Not sure where else to look. I would have thought the problem would have been solved with the parts I have replaced.

Well, still no progress. Replaced my evap purge valve, seems to be a little better after that but not by much. Also replaced my TPS as well, which made no difference. Couple things I have noticed, which seem to be a little weird. My fuel trims go farther down into the negatives when I run the A/C. When it is not running, the trims go up by a number or two. My MAP sensor reads about 10 in-hg at idle, and about 11.8 with the A/C on. MAF is flowing at 0.8lb/min w/out A/C, and 0.9 with it on. Also wanted to mention that the fuel trims have went down to -17 and -14.

I'll have to take a look at that, thanks.

I have a scan tool with live data. Ethanol reading is normal, at 10%, which is what I filled it with.

Yeah I could give that a try. Correct me if I am wrong, but wouldn't an air intake leak cause positive fuel trims, as the ECU has to compensate for the extra air?

Have a 2007 chevy truck with the 5.3, has about 100k on the engine. Truck feels sluggish until the engine hits 3.5k rpm, then will sorta suck you into the seat. Best way I can put it is that it always feels like I am towing something. My long term fuel trims are at -11 and -13 on bank 1 and 2. Have replaced- -spark plugs -MAF -changed CAI back to stock air cleaner -evap vent solenoid (the one by the gas tank) -new fuel pump (delphi) (all these parts are less than 2 months old) nothing is dragging, alignment is perfect, new shocks/struts so the truck has the proper rake angle. fuel pressure is steady at 62 PSI, drove the truck with the gauge hooked up and it did not drop under load. Injectors do not leak, with the truck off for around 5 mins the pressure did not go ANY lower than 55 psi. at my wits end, not sure where else to look. fuel economy is pretty bad too, the best I usually get on the freeway is about 15 on flat ground at 70. Used to get about 17-18. Getting expensive since I have a 275 mile drive I make once or twice a month. thanks for any feedback.

Hi, I own an 07' Suburban that is making a ringing noise occasionally. I can be stopped, moving, turning or just sitting in the vehicle with it on and it will make this noise for as long as 30 seconds or as short as 5. It almost sounds like a phone is ringing. It's coming from either the passenger side door, or the dashboard. I recently had the door apart to replace the door handle, but everything went together smoothly. It sounds more like an electrical ringing more than something rubbing against something. On the passenger side dashboard, I have a compartment with a relay and some fuses and some wiring connectors. Could it possibly be coming from there? What is the relay there even for? Thanks.