CEL question for the day

Post by **Sveedy** » 02 Oct 2020, 17:03

Well after installing the new fuel pump ( DW200 ) and driving for a couple of days ( apx 300 miles ) I got a CEL today.
" Bank 1 system too rich ". Previous to this I had been pron to running too lean under WOT, according to data logs.
Might this due to the new pump putting too much pressure on the fuel regulator and now that's failing ?
Or maybe just a bit of tweaking in the tune ? This is my inclination.
I'm running a VAST tune with white injectors so that's why I went with the DW200.

Post by **erikv11** » 02 Oct 2020, 18:48

I always feel like one instance of a CEL is not enough evidence to speculate or do repairs on. I'd see if it comes back after another ~300 miles.

Cookeh · Post by **Cookeh** » 03 Oct 2020, 05:15

If you had fueling issues previously for a period of time, perhaps you need to rest your long term fuel trims (LTFT). I cant search right now but there is a guide on MVS covering how to do so.

befarrer · Post by **befarrer** » 03 Oct 2020, 08:27

Might not be your issue, but I had another type of vehicle where I installed a higher flow fuel pump, and I later found out that it flowed more than the regulator could regulate. Which ended up with fuel pressure of 75PSI at idle, which would drop to 65PSI at full throttle. It was supposed to be 35psi. Installing an aftermarket regulator that could handle the flow, all was good. So check your fuel pressure to make sure thats not the issue, as high pressure would mean more fuel.

Post by **Sveedy** » 03 Oct 2020, 08:38

Thanks for the input guys ! I will reset my fuel trims and go from there. I'm guessing I should wait on pulling a datalog till after I give the LTFT time to readjust. And I will go and search for a pressure gauge that I can use for the fuel line. I'm guessing my tire gauge wouldn't work

Post by **erikv11** » 03 Oct 2020, 14:31

People actually do use tire gauges but it is not a good long term solution. Any pressure gauge hooked up to fuel safe line will do the trick or pick one up from the parts/tool store.