FetzerValve

Hey guys,

I'm having an issue with my AFRs rising. A month or so ago they were between 10.2 and 10.8ish. Two weeks ago they were in the mid to high 11s and today on the way home from work I was seeing mid to high 12s and even 13.0! I didn't make any changes to the truck since then except for changing the wastegate spring for a single night. I went from 6psi to 7.5 then back to 6. That was about a month ago.

I can hear a small exhaust leak in the morning but once it warms up it goes away. Would that be throwing off my wideband? There is a test and tune night coming up at the local strip but I don't want to blow my truck up trying to get a log for my tuner.

Any advice?

Thanks in advance!

Truck is a 6.2 with BW S475 tuned at 6 psi. Stock fuel system.

FFDP

iTrader: (2)

Log fuel pressure on the street, view and see if the pressure is dropping.

If it doesn't, then it shouldn't be pump related.

Any exhaust leak before the wideband can skew readings.

FetzerValve

I'm logging with an autocal...I'm not sure how to see fuel pressure. I know I can send a quick log file to my tuner but he takes weeks to get back to me. After Wednesday the next test and tune night isn't until august so I'm hoping to get some answers soon!

FFDP

iTrader: (2)

Welp, then get a actual fuel pressure gauge and tape it to the windshield.

You would have to have the fuel pressure channel/pid or whatever EFI Live calls it in the log list to see what the numbers are in the data log to see it.

If you have to wait weeks to get a tuner to get back to you, find someone else or do it yourself. That is just stupid to have to wait that long.

FetzerValve

Just did a little driving and I'm thinking it might be the fuel pump. Once I get to about 3 psi the wideband drops from 14ish to low 12s then slowly climbs as rpms climb. I'm guessing it's running out of fuel. The truck has 80K miles on it and is still running the factory flex fuel pump. Anybody know what kind of mileage to expect out of the pump?

Im going to send the log off to the tuner. Hopefully he gets back to me soon. I feel like I could teach myself how to tune my truck in the time it'll take for him to respond. I'm sticking with him for now because the truck has been running well for about a year and he gives me free tune updates when I make changes but I'm beginning to get tired of waiting weeks for him to respond to an email containing simple questions...

FetzerValve

Here are a couple log files. Traffic was pretty heavy so it's not the cleanest data but maybe it will help...

FetzerValve

I think I found rail pressure in the data log. From what I see, it's dropping from 58 to about 46 at WOT around 5500 rpms. Could this be why my wideband is showing the truck is leaning out?

Lane_Hesser

Most definitely

silver-mod-o

iTrader: (15)

Put a fuel pump in it before your draining parts out of the oil pan...

FetzerValve

How much pump do you think I'd need? Future plans for the truck are 1000cc injectors and 10-12psi. Due to the fuel around here (only 91 at the pump) I may go E-85. I don't really want to deal with meth injection...

Will a single Walbro 450 in the tank be sufficient for that setup?