175rgr

Here is what Happen:

I was leaving work coasting around a roundabout when the fuel pressure gauge went red and fuel pressure dropped to 20 PSI. I coasted into a parking lot shut the car off and discovered the quick disconnect fitting was bad and would slide on and off with ease. I bent the internal metal prongs in the fitting pushed it together and drove it 15 miles to get a new fitting. The entire 15 mile drive the car was running super rich, I'm talking 9.5 to no higher than 11.5 a/f the entire drive to the performance shop. I get to the shop and install a new fitting everything is good no fuel leaks. The entire drive home it sat at around 9.5 - 10.5 a/f. I got home, double checked everything, unplugged the battery for 30 min. Plugged it back in, took it for a drive, same thing, now at idle it sits right at 12.3 - 12.7 a/f instead of the normal 14.7 - 15.0 it would sit at before. Also before this happen when cruising, 6th gear highway speed it would bounce from 14.5 to 14.9, now it wont go any higher than around 11.8 at highway speeds.


I've checked the fuel pressure regulator, all is well.

Car:

408 stroker
D1SC
A&A fuel system

So a quick rundown again.

All is fine, fuel line fitting breaks, I repair it, suddenly car is running extremely rich.

I'm at a complete loss here any help would be much appreciated.

DOUG @ ECS

Verify your wide band 02 is good by looking at the factory 02 readings.

Steve@C56

Hi,
True or false rich running, that is the question !

Is idle not high ? (if running rich, idle should be high)

No DTC ? (if rich, LTFT should be max out and give DTC)

Water temp gauge ok ? (if water temp is too low, the tune automaticly enrich for safe)

Can you plug a scan for read Water temp/IAT(if is too high, normal to be rich)/LTFT-STFT bank 1&2/AFR commanded/o2 front bank 1&2

madmatt9471

You also might look at the Front O2's and see what they look like as well as the plugs -

If you got a set of extra's put them in and see if that straightens it out - it's possible they got drowned and are fouled -

This happened to me when my O2 went bad on the drivers side! it fouled out the plugs and was pig rich.

At least it will be a starting point and a quick inspection will let you know what's possibly going on!

Thanks,Matt

175rgr

Thanks for the quick replies, I pulled the o2 sensor and re-calibrated it. Read fine for about a mile and then went back to 11 ish a/f. about 2 hours later i went the parts store to pick up a new o2 sensor and it seemed back to normal running around 14.5ish cruising around. I'm going to drive it all day tomorrow and see if anything changes, if it goes back to the 11ish then im going to swap the wideband and see if thats the issue. It doesn't seem to be running too crazy, no black smoke no rough idle so im thinking it was a crazy scenario that the wideband went bad the exact same time the line broke, odds are few and far between but ive seen crazier things happen.