Fuel smell of fresh gasoline under boost. I've run out of leads.

Not LIM gasket as that was new; torqued down too

Not the aluminum check valve as that's new and tested

Not the brake booster check valve as that's new and tested out

Not the FPDamper as that's new

New lines and plastic gas catch tank

New fuel lines under rat's nest and new OEM clamps

New silicone lines for rat's nest with zip tie.

Besides pulling the injectors, replacing the fuel pressure regulator, where else can I look for the source of this fuel smell only under boost?

 

how about the charcoal canister? its behind the driver's seat under the car near the fuel filter I believe.

I'm troubleshooting my own fuel smell as well. So far replaced the aluminum check valve, but it still smells slightly. Do you smell it *while* accelerating under boost or more after a shift? Mine smells after I shift under boost then the scent goes away. Have not noticed any leaks or anything under hood.

 

You know now that you guys mentioned it.I too have a fuel smell.Its really bad.Probably worse than your cases.I get the smell under boost and also when I turn on my heater.But generally I smell it faintly all the time.
Ive checked for leaks and im finding none.Anyone experiencing hesitation or bucking when cruising? Decreased performance? Im thinking charcoal canister or leaking injector o ring or the injector itself.
Car now has new vacuum lines,new fuel pressure regulator,new rats nest solenoids,new fuel filter.Ive got new blitz injectors for the rx.but havent gotten around to changing the old ones out.In case you guys were wondering the blitz injectors in 550 and 850 side feed fit on fd's.Theyre actually nippon densos/blitz.And about 125 a piece new versus the mazda ones which are like 300.Same brand huge price difference.

 

Have any of you replaced the rubber line to the brake booster from the firewall recently? Theres a one-way valve embedded in it, and if you remove it (like say, to use a silicon hose instead) you get the fuel smell.

 

If you smelled fuel all the time, try this test. Shut the engine off, open hood, sniff the area near the alternator and the pressure chamber. If you smell fuel there, it's the Fuel Pulsation Damper. If it's the FPD, replace it with a new one. While you're at it, replace the injectors as it takes just as much labor to do.

 

Peter, I saw your post and verified with a new check valve from Mazda.

Regarding the price of Mazda injectors, yep they ran $1200 for all four when mine leaked thru the injector casings.

 

I paid about 550 for 4 new ones from blitz.same injector nippon denso's

 

If you are not smelling fuel until you are under boost (i.e., at higher RPMs), then the leak is most likely in the secondary fuel rail. The secondary fuel injectors only operate at times of high fuel need such as when the turbos are at full song. I suspect that the o-rings between the injector tips and the block fuel ports are leaking. Before you unbolt the secondary fuel rail, however, I would suggest that you activate your fuel pump while the engine is off to pressurize your fuel system. You can do this by placing a short wire in the proper slots in the diagnostic probe located in the engine compartment to the driver's side of the car. Rather than explain which one's to activate, I would recommend that you refer to your shop manual. It describes in several different places how to activate the fuel pump. Pressurizing the fuel system is a good way to check the integrity of the entire fuel system under the hood.
If pressurizing the system does not reveal the leak, then you may need to unbolt the secondary fuel rail to visualize the condition of the o-rings where the tip of the injectors pass into ports in the top of the block. Be sure not to unseat the injectors from the fuel rail as this is not necessary. If you do, you will then need to replace the injector o-rings to properly re-seat the injectors.

 

thanx for the info.ill check out the are and see if it where the smell comes from.I knew it was something stupid.How much do fuel pulsation dampners run?

 

thats definatly an interesting thing to know as well.Ill be paying more attention as to when the smell gets stronger.Anyone know when the secondary injectors come online.I think its 3k but i could be wrong.

 

Removing the UIM, rats nest and pressurizing the fuel system are what I was trying to avoid doing as the injectors were replaced with brand new ones 30K or 5 years ago.

The thing about my secondary fuel rail is that I never unbolted from the LIM of the bad engine when I transferred over to the reman 1 month ago. May be it hardened while sitting around for 3 months?

 

i have the same problem and didn't notice it til i put on my k2rd secondary rail. i think the problem is there's really no good seal on the 1600's to the lim and as boost builds, some fuel leaks out. i plan on making/finding a really good o-ring to seal it up and possibly get rid of it

 

Did any of you guys find solutions to your problems?

 

I solved my fule smell issues by venting the catch can back to the turbo inlet. Would get an occasional fuel smell under full boost with the vented catch can.

 

Same here
Fuel smell under high load only
Is this dangerous ?

 

i fixed my FPD and got a new aluminum check valve.

Yassu, Riccardo. Yes it can be very dangerous. Usually it means that the FPD is leaking.

 

I had the same problem which did not get resolved until the primary injectors were replaced. Prior to replacing the injectors , I had replaced the FPD, fuel lines and o-rings and it still leaked. Don't drive until you get this resolved as many RX's have met their demise due to this problem. I.E engine fires

 

the boost related fuel smells are usually lim manifold gaskets, or the injector grommets are leaking fuel mix out under boost. it is dangerous as fuel vapor is very combustable