Fuel out the what??.... that's a new one.

Car is a bmw 86 325e. Low pressure turbo w/ RRFPR for fuel. Ran fine w/ this setup w/ old turbo for ~2k. Just finished install of new, better sized turbo.

First test drive went well Monday night. Starts up and commutes to work Tuesday just fine. No hard start or anything.

Little lean near target boost. Go out to car after work tuesday and adjust RRFPR base pressure up some and back gain down a bit, sincegain was maxed (oops). Go to start and a bit of sputter, then Nada. Crap. Back off the pressure adjustment but still Nada. Double crap. I've got not enough tools and it seems flooded. Regroup for tomorrow.

So tonight I go to the work parking garage w/ appropriate tools and spare set of plugs. Go through the motions, no change (cranks, no response). Hmm, maybe spark problem. Nope, coil and dist test out fine.

Now I'm feeling stumped and frustrated. Start poking more and finally notice that there's fuel in one of the vac/boost reference lines. ?!?!?!? How the hell... OK, let's jumper the FP relay, and... Shoots gas out the vac line. Trace it back and that's when I discover the source is the motherloving reference line for the stock fpr.

no drips out the stock return port at all. I macguyver a line splint w/ a pen body and scavenging available hoses to confirm that the flow out the stock fpr through the downstream RRFPR isn't blocked. Best I can tell is that I must have maxed the RRFPR base pressure adjustment accidentally, creating a block and this stock fpr failure is the result.

I'm on the metro home now to get a spare fpr to try tomorrow. Anyone else ever had one fail like that??

obviously not me, but good that you found out this issue before this weekend, lol.

I've had a fuel pressure regulator fail on a stock M20 engine; when I pulled off the vacuum line, gas was dripping out. The car was hard to start, but once it did it would run fine.

Been There Done That.

irish44j wrote: obviously not me, but good that you found out this issue before this weekend, lol.

Yeah! I was much more annoyed until that occurred to me on the way home. Especially since I've got a spare.

I've seen one that would shoot gas halfway across the shop, and lots that dribble.

turboswede wrote: Been There Done That.

Really? What was the engine/setup?

Normal failure mode for regulators. The extra fun ones are the GM "spider" systems because the regulator is inside the intake plenum so you have to disassemble to find out that it's hosed (hosing).

Hell, to this day, the first thing I do on any Vortec 4.8/5.3/6.0 is pop the hose off to see if there is fuel in it.

bluej wrote:

turboswede wrote: Been There Done That.

Really? What was the engine/setup?

Dodge Daytona Shelby Z, they use a pretty standard Bosch regulator. Some BMWs, Volvos and Porsches use similar regulators.

Knurled wrote: Normal failure mode for regulators. The extra fun ones are the GM "spider" systems because the regulator is inside the intake plenum so you have to disassemble to find out that it's hosed (hosing). Hell, to this day, the first thing I do on any Vortec 4.8/5.3/6.0 is pop the hose off to see if there is fuel in it.

that's the first thing i do when trying to figure out weird hard starting or over rich conditions on any EFI vehicle with a vacuum referenced fuel pressure regulator. it's one of the most common failure points, and usually the easiest thing to access to check and replace.

That's a fairly common failure in the Bosch FPRs used in SAAB c900s too. It might even be the same FPR that you have. It might have just been old and ready to fail. Replace it and carry-on.

Clearly, I had no idea. Initial googling didn't show much , hence the thread. Thanks guys, good to know it's more than just a random failure.

I recently had a similar mystery no-start/flood issue with my Volvo due to OEM Bosch FPR:
http://grassrootsmotorsports.com/forum/grm/fuel-pressure-regulator-symptoms/83088/page1/

This thread reminded me that I'm still running the one from my "spare parts box," and need to order a new one.

• Lee

Yep, I've had that happen on a mid-'90s Ford van, 351w. It would run, but ran terrible. Black smoke from the tailpipe and all the tell-tale signs of running pig-rich. I checked the fuel pressure thinking that the regulator might be stuck and it only had about 10-15 psi at the fuel rail. That's when I started scratching my head. It shouldn't even run at 10 psi, let alone run rich! I don't even remember what made me think to take the vacuum line off of the FPR, but when I did it was a freakin' geyser. Apparently the injectors weren't spraying much at all, but the FPR was dumping tons of fuel directly into the intake manifold.

sigh

Swapped at lunch and still no start. Ugh.

Flooded/cylinders washed down?

solfly wrote: Flooded/cylinders washed down?

that's what I was thinking. Maybe pull the plugs and let it evaporate?

irish44j wrote:

solfly wrote: Flooded/cylinders washed down?

that's what I was thinking. Maybe pull the plugs and let it evaporate?

Left it that way over night.

I ended up pulling the fuel pump relay and still getting lots o fuel on the plugs. Started pulling pieces, starting w/ the intake/TB connector. Took a minute but finally signs of life! Except it was a moment later that fuel GEYSERED out of the intake. Very exciting! OK, makes sense, must have been VERY full of fuel from cranking before I found the faulty fpr. I'm lucky I didn't h-lock it.

Soak up as much as I can and let it crank w/ FP relay still off, roar to life, let run for a few secs (vac leak on purpose) them kill it. Do again. Eventually it won't run (fuel gone). Hook back up intake. Same process. Crank it up and run for 10 secs w/ fpr off. Eventually won't start anymore. Fp relay back in. Pray. Crank. SUCCESS!!

Proceed gingerly 8 miles home to change the oil asap.

You may want to check for a sticking fuel injector, or some other malfunction of the fuel system. One of my old SAAB c900s had an ecm failure that held the injectors WFO anytime the key was on. That literally filled the engine and intake manifold with fuel similar to what your describing. I'm quite surprised that I didn't hydrolock the engine.

Change the oil twice. My cousin lost a red block motor (on a car he'd already sold) because the oil was diluted by fuel. Change it once, run it through a full heat cycle, then change it again. Or at least check to see if the oil smells like gas.

Noted, thanks!