Mahjik

iTrader: (1)

Ok, I've been dealing with a gas odor problem for a while now. Had the fuel system pressure checked for leaks twice with no luck.

Anyway, decided I would take a look around myself instead of paying a mechanic a buttload of money. I just found out that not everyone put on this earth has a little "mechanic" in them. That trait was definitely left out of me... I'm in the depression stage that I'm not sure if I'll be able to get all this crap back into the car... sigh anyway, onto the question.

In searching the forum, I see the similar steps for removing the injectors however there is one thing that differs from the manual. The manual suggest that you need to release the fuel pressure first, but none of the steps people have posted here seems to list that when pulling the injectors. Is that necessary for this application (I'm going to replace the injector o-rings since I'm going to be in that area)?

Thanks for any help...

Mahjik

iTrader: (1)

Thanks. I'll do that...

High pressure line, eh? Back to the manual.

kempo

iTrader: (2)

remove the fuel pump relay located where the main relay is in the fuse box in front if the brake pump.then crank the engine that will take the pressure out of the fuel lines. if you are already in there you should also think about chaging your fuel pulsation damper part# n3a2-20-180 this is the main cause of engine fires on fds. there is also a fuel line upgrade kit that has all the fuel hoses under the UIM that somtimes will crack due to the extreme heat they are exposed to during so many years part #is N3A1-13-S70A. maybe if you dont find the fuel leak at lest that will make your car safer down there an you can forget about your car having the engine fire situation .

Street King

Kempo:

Does the FPD usually cause most "oder of gas" smells? Whats an average price for the FPD? Iam getting the fuel smell so i will be doing the fuel hose upgrade. Agian how much will this cost?

Thanx

SanJoRX7

I believe that the FPD is the subject of a Mazda recall, no? In any event, it has been listed as the "culprit" in many engine fires. If you're getting that fuel smell, and you can't find the problem, replacing the FPD is probably a bit of cheap (how cheap I don't know :P) insurance against a fire.

One of the other things that people seem to replace when they're having this sort of trouble is the injector o-rings. Seems to me they'd be relatively inexpensive, and if you're already knee deep in the poop, might as well replace those, right?

Mahjik

iTrader: (1)

Street King,

It depends when you are getting the "gas odor" smell. From what I've read, if the FPD is leaking, you can smell it at idle inside the engine bay. The engine doesn't necessarily need to be under any load for it to happen (again, this is what I've read, not experienced).

Mine is happening ONLY under hard acceleration. If I just drive the car without getting on it, it never happens (at least not enough to make it into the cockpit to be noticed). I'm thinking mine is a lose hose in the purge system, a bad PCV or a leaky secondary injector (anyone else with ideas?). When do you get your gas odor?

As far as the FPD, the part usually runs about $130, however paying for labor to have it installed is the problem. It will probably cost around $600 in labor for the installation.

I'm down in that area now working on my car and let me tell you, I wish I had never started this project. I'm no mechanic and this stuff does not come easy for me.

I'm just hoping my o-rings get here today or tomorrow so I can start getting the car back together before I completely forget where things are "suppose" to go...

I'm spending tonight cleaning out the throttle body and UIM with some carb cleaner while I'm waiting.

es

If your smelling fuel after a on boost run then the problem could simply be that little aluminum one way check valve under the TB elbow in front of the throttle body.

Replace that first. If you are going down to the injectors (primaries anyhow) you might as well go ahead & replace the FPD. That thing has a rubber nipple on the end, & after it ages the diaphram seal inside leaks & the nipple ends up spitting fuel.

Good luck.
Eric.

Mahjik

iTrader: (1)

Is that the PCV valve? That's the one I believe is my problem. I'll be checking it tomorrow...

Street King

I have a 94 FD and I cant smell it driving or idling. Iam not sure when exactly it happens its not bad enough to where iam OMG where is it coming from. I just get a wiff of it. Liked last time I went to visit a friend, and someone there wanted to see under the hood so I popped it. You could smell it and he was like it smells like gas, why? I just made some **** up about the cat being gutted..LOL! I only really smell it after I drive it and pop the hood. IF I idle it and pop the hood I cant smell it, only after a hot drive. Its not constant either. sometimes it does it sometimes it doesnt. 108k miles on car, broken in engine and turbos.

es

PCV (Positive crank case valve) is the big plastic valve that's between the UIM & the oil filler neck. I'm talking about the "Purge Control Valve" (so mabe it is PCV?) check valve.

There is a solenoid valve (and I don't remember what it's bolted to, but it's not really in the nest), and the hose between the UIM and that sol valve is the ONLY ALUMINUM check valve you'll see under the hood of an unmolested FD.

The other hose goes from that to the catch tank that bolts to the bottom of the Throttle body. Since you'll have the elbow off anyhow you might as well spray that tank out with some carb cleaner.

Enjoy,
Eric.

Mahjik

iTrader: (1)

Well, I don't know Street King. It really sounds like you do have a fuel leak. I've never been able to smell mine while being under the hood, ever (which is mainly why I believe it's more of the purge control valve or just the purge sysytem in general).

I just figured if I was going to remove the UIM, I may as well head for the injector o-rings and replace them since I don't want to do this again any time in the next 50 years. I'm still going to take a look at my FPD just in case, but I don't have any plans to replace it if it doesn't need to be...

es

Street King, It sounds to me like you need to replace that Fuel Pulsation Damper! While your in there go ahead & replace some fuel hoses to.

es

Mahjik, The primary injector are the deepest thing on the top of the motor!

If your going in there plan on doing the full hose job, probably a MOP injector oil feed line, & go ahead & have the injectors cleaned & balanced (which should replace the O-rings).

IMO you should probably rule out the simple stuff before you go submitting that much time & money into a task.

Street King

Thats in the line of list of things to do after I pay my tickets. Hey majik when do you smell the odor of gas if you say you never smelled it under the hood?

Street King

And what does the Fuel Pulsation Damper really do?

Mahjik

iTrader: (1)

Thanks for the advice es... Unfortunately, I'll probably need to at least get to the fuel rail as my 10mm socket fell and dropped there...

sigh....

I only smell it in the cockpit under hard acceleration. Usually (for some reason) I only notice it coming out or near the top end of 3rd gear. I don't seem to get it any other time. It's not a lot. I had a mechanic ride with me and he never did smell it , but I imagine most mechanics get used to certain smells so it takes a LOT of it for them to notice anything out of the ordinary.

Mahjik

iTrader: (1)

It helps smooth out the fuel pulses (pressure fluxuations)....

es

Mahjik, Bummer, try a magnet. :P

Street King, like Mahjik says the FPD helps to maintain a consistent pressure at the injectors, & relieves some of the stressfull current spikes through the fuel pump.

Many have ran Bosch pumps & custom rails with no dampening & the pumps last a pretty good time. On the other hand a local Friend just fried his ~5 yr old Bocsh pump. Don't really know why, maybe it was his RRFPR being set to 80ish PSI, maybe it was because of the lack of a PD?...

Mahjik

iTrader: (1)

BTW, just to update the thread in case anyone searches on it....

In my case it was the one of the check valves in the purge control system. It was stuck open. Replaced it ($19 from the dealer) and no more gas odor.

hapa

Mahjik, was it the aluminum one by any chance? Also do you have the part number? This is excellent information for people to research.

eric

Mahjik

iTrader: (1)

Yes, it was the aluminum one. I think the part number was: NF01-13-890

It was $17.35 from the dealer...

daem0n

Hey, I was getting a gas smell under WOT and figured I would replace the aluminum valve just in case it was that since it is so cheap. And it turned out it was - no more fuel smell under boost

rx7speed811

sorry if this is a really dumb question, but can somebody please explain to me exactly what the purge system does? i would like to know before removing it when i do the full non-seq/block off conversion.