Help trace fuel smell

[TuRBoTaLooN]

First, I'd like to say I've searched for some answers on here but all the threads seemed to just end without any resolution (aside from finding spilled octane booster in the back seat) or process to determine the issue.

A little history...
A month ago my car had a re-wired 190 pump, RC 550's, 16g, stock-ish intake pipe with all vac lines attached (except for BCS), pretty much stock everything else. Then I completely changed everything. It now has an FP 3150, re-wired 255 pump, PTE 780's, FP race manifold, FP 2.5 o2 housing, 3" exhaust, FP 4" intake (recirculated bov), unknown FPR at 43.5psi (vac line not attached when reading psi). The VC breather goes to a vented catch can, so it does not reconnect to the intake anymore. The emissions vac line (I think that's what it is), I simply plugged with a vac cap and zip ties.

After installing all this stuff, things seemed to be ok, no leaky injectors, fuel lines, or poor performance of the car. I did notice that the gas gauge does not work correctly anymore as it doesn't always go up to F when I fill it up, it sometimes jumps around (slowly). Other than that, no issues. Over the last couple days, I noticed a faint smell of fuel when I get in the car before I even start it up. That's when it is the strongest. Every now and again I VERY faintly smell it while idling or moving slowly. I can really only smell it in the the car. I checked for leaks under the car and in the engine bay by the FRP and injectors and saw nothing. I KIND OF smell it a little bit by the FPR, but it was hard to smell with the motor running. I lifted up the back seat and there didn't seem to be any fuel leaking by the fuel pump. Nor did I find the smell coming from that area. The smell seemed to be coming from the vents. The only thing I changed that was a day or so before I started smelling this was I put in new NGK BPR7ES plugs and new NGK wires. I havn't had a chance to pull the plugs and take a look, but I plan to this weekend.

Basically I am asking for some help as to where I should start looking, if this is a common problem, or more precise ways to tell if a fuel component is leaking. If it helps any, I am getting about 180 miles per tank, but that's also with doing a lot of 2nd and 3rd gear pulls while I'm tuning. Idle and cruise AFR are pretty consitent at 14.7 (via AEM UEGO W/B), and around 11:1 at WOT. My AEM o2 sensor is mounted in the rear o2 section of the exhaust, but I have no cat. I also noticed that when I let my foot off the gas to decelerate, the AEM shows A/F going rich for a second or two before it goes lean and read "---". I hope I have provided enough information. Thanks ahead of time for any assistance I can get from you guys.

 

[daren_p]

How is the FPR connected, did you can out any fuel lines with aftermarket SS braided hoses, etc?

 

[kergilman]

I noticed a faint smell of fuel when I get in the car before I even start it up. That's when it is the strongest. Every now and again I VERY faintly smell it while idling or moving slowly. I can really only smell it in the the car. I checked for leaks under the car and in the engine bay by the FRP and injectors and saw nothing. I KIND OF smell it a little bit by the FPR, but it was hard to smell with the motor running.

If you have your vent set to circulate outside air, you will pull air from above the top of the firewall which might smell of gas if your leak were right around the TB area... Your fuel economy is really ugly. If you have that sort of leak, you should be able to see "stained" area from dust mixing with it at the point it is leaking.

 

[TuRBoTaLooN]

How is the FPR connected, did you can out any fuel lines with aftermarket SS braided hoses, etc?

The FPR is bolted onto the fuel rail. The teflon tapes seems to be inaffectly applied as there is no tape where the thread goes into the fitting. I did not replace any lines with braided hose. The fuel line from the pump was previously replaced by the old owner with braided steel.

 

[TuRBoTaLooN]

If you have your vent set to circulate outside air, you will pull air from above the top of the firewall which might smell of gas if your leak were right around the TB area... Your fuel economy is really ugly. If you have that sort of leak, you should be able to see "stained" area from dust mixing with it at the point it is leaking.

So far I havn't seen aything.

 

[daren_p]

The FPR is bolted onto the fuel rail. The teflon tapes seems to be inaffectly applied as there is no tape where the thread goes into the fitting. I did not replace any lines with braided hose. The fuel line from the pump was previously replaced by the old owner with braided steel.

I was going to mention if you did just swap in some aftermarket lines, the fuel smell could be coming from the lines themselves as the fuel vapours can actually permeate through the synthetic rubber liner, causeing a fuel smell even without any leak but if the lines were already installed & you didn't notice the smell before, there must be another source.

Looks like you have DSMLink so you can easily turn on the fuel pump without the car running, making it much easier to find the leak, if you have one.

 

[blownturbotsi]

Check the rubber seal on the gas tank where you remove the fuel pump. I know it was a pain for me to change on my friend's car, so it might not have been put back correctly or may be bad. Now I believe there are lines that go to the front of the car from the fuel tank for vacuum or venting, this might be what you were mentioning that you capped, try removing the caps and hook them back up and see what happens. Good luck!

 

[TuRBoTaLooN]

Check the rubber seal on the gas tank where you remove the fuel pump. I know it was a pain for me to change on my friend's car, so it might not have been put back correctly or may be bad. Now I believe there are lines that go to the front of the car from the fuel tank for vacuum or venting, this might be what you were mentioning that you capped, try removing the caps and hook them back up and see what happens. Good luck!

I really don't want to take that cap off again and check because it's a major pain in the butt, so I'm going to leave it until last.

I put two brass barbed fitting in the 4" FP intake I have and connected the canister line to it and the breather hose from the VC to it. I started it up (cold start for a few days) and it started to run rich, like high 11's, low 12's for a couple seconds, then went to 14.7. I let it warm up and checked STFT with Link and it was like -5%, -6%. I had my global at -35% for PTE 780cc injectors which seemed lower than it should be. I changed global to -37% and turned the car off so the sealant could cure overnight.

This morning I drove it to work. When I got in to start it up there was still a faint smell of fuel, but I'm going to wait to see what happens when I leave today before I start looking elsewhere. Logged my commute to work, and LTFT Lo was like 6%, so I changed global back down to -36%. Car seems to run a little better now with those vac lines back in the intake.

What gets me is I did the fuel pump, injectors, and FPR almost 3 weeks ago, and never had this fuel smell. Then I did the turbo swap like 2 weeks ago with new exhaust components and only got the smell of new metal being heated up and broken in. Then about a week ago I installed the FP 4" intake, capped off the breather line from the VC, so the line goes from the VC to a vented catch can, and capped the canister hose. Then two days later I installed new NGK plugs and wires. It seems like after the plugs and wires I started smelling this fuel smell. I want to take out the plugs and check them, re-gap, and put back in to see if that's it too if this doesn't work.

 

[andy4g63]

I had a similar problem,not so long ago.Evarything was connected right,no leaks,nothing.Then my friend told me to check the following thing:
There is a blue colored one way valve on top of the tank.Nas an arrow on it.It is just for like ventilation purposes and is connected to the canister in the engine bay/mine was disconnected BTW/.Then i checked that valve by blowing thru it in either direction.You should be able to blow only the way the arrow is pointed/it is a one way/,but i was able to blow thru in both directions,so i replaced it and the smell went away.I hope it is that simple in your case too.

 

[dalatinromeo]

I really don't want to take that cap off again and check because it's a major pain in the butt, so I'm going to leave it until last.

I put two brass barbed fitting in the 4" FP intake I have and connected the canister line to it and the breather hose from the VC to it. I started it up (cold start for a few days) and it started to run rich, like high 11's, low 12's for a couple seconds, then went to 14.7. I let it warm up and checked STFT with Link and it was like -5%, -6%. I had my global at -35% for PTE 780cc injectors which seemed lower than it should be. I changed global to -37% and turned the car off so the sealant could cure overnight.

This morning I drove it to work. When I got in to start it up there was still a faint smell of fuel, but I'm going to wait to see what happens when I leave today before I start looking elsewhere. Logged my commute to work, and LTFT Lo was like 6%, so I changed global back down to -36%. Car seems to run a little better now with those vac lines back in the intake.

What gets me is I did the fuel pump, injectors, and FPR almost 3 weeks ago, and never had this fuel smell. Then I did the turbo swap like 2 weeks ago with new exhaust components and only got the smell of new metal being heated up and broken in. Then about a week ago I installed the FP 4" intake, capped off the breather line from the VC, so the line goes from the VC to a vented catch can, and capped the canister hose. Then two days later I installed new NGK plugs and wires. It seems like after the plugs and wires I started smelling this fuel smell. I want to take out the plugs and check them, re-gap, and put back in to see if that's it too if this doesn't work.

I still have to go with the capping of the vaccum lines or the fuel pump install as the culprit. I would give it a couple of days for the smell to go away. Clean the car so the smell goes away. Just to see if it came from the lines being capped. If it comes back I don't think its from them being capped.

If it is still there then I would go pull the back seat and see if there is a leak somewhere. Maybe it started leaking and now you finally have enough spilt there to actually smell it. You might also want to check the afpr to see if it has begun to leak at one of the fittings. I know it is in the car but you never no.

 

[TuRBoTaLooN]

I had a similar problem,not so long ago.Evarything was connected right,no leaks,nothing.Then my friend told me to check the following thing:
There is a blue colored one way valve on top of the tank.Nas an arrow on it.It is just for like ventilation purposes and is connected to the canister in the engine bay/mine was disconnected BTW/.Then i checked that valve by blowing thru it in either direction.You should be able to blow only the way the arrow is pointed/it is a one way/,but i was able to blow thru in both directions,so i replaced it and the smell went away.I hope it is that simple in your case too.

That's a great idea! I'll definitely take a look at that. It would be a nice simple fix.

If it is still there then I would go pull the back seat and see if there is a leak somewhere. Maybe it started leaking and now you finally have enough spilt there to actually smell it. You might also want to check the afpr to see if it has begun to leak at one of the fittings. I know it is in the car but you never no.

I was thinking of pulling out the FPR because I used regular teflon tape, but recently I bought the Yellow teflon tape made for fuel fittings just like this one. That should help too.

 

[TuRBoTaLooN]

So I drove home after work after a bit more closed loop tuning. Good news was I got the LTFT Lo to like 1.8% which I thought was pretty good. I had some time when I got home so I took out the back seat to inspect the fuel pump. Looked good, couldn't smell fuel, but I added zipties to the rubber lines along with the metal clip to make sure its on there.

Then I walked by the car and heard something from under the hood. Popped it up, and sure enough I hear air and see fuel leaking from the 2nd injector in from the left. Popped it all out and sure enough the o-ring broke. I took out the injectors and fuel rail and FPR. I got some yellow teflon tape from loew's so I re-did the FPR fittings. I have some extra o-rings at my mom's house (thank god), so I'll pick them up tonight and probably put everything back in tomorrow. I'm going to make sure I lube the o-rings with oil A LOT when I put them back in. That was where the smell was coming from.

 

[turbosax2]

You don't need A LOT of oil on the o-rings. Just coat your finger with some oil and rub it around the o-ring. I actually prefer to use dielectric grease instead of oil.

Also, are your fittings on the afpr AN fittings? Teflon tape shouldn't be used on AN fittings.

 

[TuRBoTaLooN]

You don't need A LOT of oil on the o-rings. Just coat your finger with some oil and rub it around the o-ring. I actually prefer to use dielectric grease instead of oil.

Also, are your fittings on the afpr AN fittings? Teflon tape shouldn't be used on AN fittings.

It does not have an fittings. It is a brass barbed fitting.

Can I use the o ring from my rc 550 injectors? Or am I stick ordering pte o rings and waiting for them to arrive?

 

[TuRBoTaLooN]

I guess I answered my own question. I ordered an o-ring set for PTE injectors last night, and they should be here tomorrow afternoon. Then I can button her up and hope for the best.

Thanks for the help guys.

 

[TuRBoTaLooN]

Put in the new o-rings today in the rain.

Anyway, I didn't change my DSMLink settings, and took a drive. LTFT Lo ended up at like 11% when I was done! The timing curve looked good though, and just a tad of knock in the upper RPM range.

 

[TuRBoTaLooN]

Well, last night the car looked ok...at least ok enough to drive. This morning I started her up fine, but after a few minutes started sputtering kinda and running EXTRA SUPER lean....like 19:1 -ish. I immediately turned her off, kicked the tire, and drove the slowbalt to work. I gotta take a look at it first thing when I get home. I'm assuming I didn't seal the injectors in correctly.

Any advice on tips to help make sure the injectors are properly seated when installing them with the fuel rail?

 

[blownturbotsi]

I like to just stuff them in there.

 

[TuRBoTaLooN]

Apparently that hasn't been working for me with these PTE injectors. I broke 2 o-rings after maybe 200 miles of driving, and now it seems to be leaking air somewhere. Something isn't sealing. And I'll be really pissed if more o-rings went!

 

[TuRBoTaLooN]

I'm an idiot and should have just replaced the seals last night when I put in the new o-rings since they came in the set. The #1 injector seal was torn and so it was sucking in a lot of air. Put in 4 new seals and she's good as new.

Did a quick tune and global is -37%, 315 deatime, and I just added a few degrees of timing on the low end.

Thanks for the help guys!