Flooding Issue S5 NA
 

Hello,

I recently got my motor rebuilt and streetported at Banzai Racing. So before it even starts, yes, I have plenty of compression.

I have the BAC and ACV blocked off, the OMP was bolted to the fender at one point and I learned that is a No-No on S5's due to how computer oriented this is compared to the S4, so I put the OMP back on and set screws are in the injector output holes. My rats nest has been simplified down to like 4-5 vacuum lines. I also have new Injectors that are rated about 510ish CC after testing. I still have the original ECU in, and also have a backup in case my OMP fried the ECU when bolted to the fender which I have yet to install. I have plenty of spark when I tested, Tuning on the brand new TPS is spot on, timing is dead on, everything looks fantastic. And everything is new under the hood entirely. I have already tested an replaced a bunch of relays, fuel pump wiring is refreshed and I have a new fuel pump in as well. Vac lines are all hooked properly, everything is entirely sound, I premix 1 ounce of TCW3 2cycle (valvoline multi-purpose) per gallon. Car starts up for 2 seconds and sounds really smooth, then it floods itself out immediately after. I have pulled the battery to reset the computer, I have tried just about everything on every forum I have seen. Never cheaped out, everything is properly done. Anyone have any idea why it might be flooding itself out. I am completely stumped and want to break in my motor and drive my car for once.

Thanks in advance.

doesn't sound like it flooding out to me, sounds like the fuel pump is getting shut off

I'm not sure how s5's are with the AFM, s4's use it to keep the pump running. You should have a connector (green or yellow) around the area where the air pump would've resided, will only have 2 prongs, put a jumper wire on there and see if it will stay running

also, its not a no-no to leave the OMP tied off to the side, if anything it helps prolong the life of it because its not near the heat of the exhaust

It sounds strange but I've seen the S5 flood easily if the car is not on level ground. I forget if it floods when the nose is low or high but I have seen it.

The car is in my garage so it is nice and level, and the car is definitely stumbling out from flooding. You can smell it, you can see the poof of smoke out the exhaust, and it bogs out the whole garage. I'm sure its puking the fuel in because every time I try again, I have to unflood the motor by the foot pedal cutoff switch.

I have heard that the OMP not being on the motor can fry the ECU on S5s. I am getting a spare ECU today so I will be able to try again soon. From my research, it is rare for an ECU to cause flooding, but I might be just that one person that got unlucky with a bad ECU causing it this whole time.

I appreciate the input so far, I will try it out and take a good look at the pump too. Thanks!

I'd love to hear the "theory" that explains this phenomenon.

same here, I could see it on a carb'd engine, but even then the slant of the road would have to be horrific

I had this happen to me, I hit up my buddy with a truck and we pulled started my FC after the rebuild. Once the car gets up to 15 mph or so I put the car in second gear and popped the clutch pedal up and gave her the gas pedal, and like magic the car started out of the clouds upon clouds of smoke. hopefully this helps out.

double check you for vacuum leaks
and hook up a gauge to check you fuel pressure.

Have you tried running it with the water thermosensor unplugged? Unless the sensor is new. Have you tested AFM? Have you tested AIT? Have you driven it at all? Can you keep it going if you play with the gas? If you haven't ran it for any length of time it might just need to be running for a while. The engine should be on for quite some time before you expect it to idle(sometimes).