Strong fuel smell on track

[Schneider Stang]

Hey guys, I’m hoping someone can point me in the correct direction on this one. At the track yesterday I suddenly noticed a very strong unburned fuel smell. I pulled back to the pits to make sure everything was alright and it still smelled like fuel. I couldn’t see any leaks or spilling from anywhere so I decided to let it rest for awhile. When I started to drive home, a check engine light appeared, throwing P2196 and P2198 codes (running rich). This is the second time this has happened and I can’t seem to find anything specific to point me in the correct direction of the problem here. Both times this happened after a couple hours on track where the car was fine, it’s a 2008 GT. Thanks!

 

[302BOB]

Usually that strong fuel smell at the track comes from the wallet......you surely have more problems than that....I would start at the fuel pump and work my way from there..........................

 

[302 Hi Pro]

Codes P2196/& P2198 are O2 sensor malfunctions, Bank 1 & Bank 2.

I would start there. Remember it only happens when the exhaust is super hot so testing cold sensors might not indicate a problem, yet they can fail when hot.

Here is a list of possible culprits:
Oxygen (O2) or A/F ratio sensor or sensor heater malfunction

Open or short in O2 sensor circuit (wiring, harness)

Fuel pressure or fuel injector problem

Faulty PCM Intake air or engine vacuum leaks

Faulty fuel injector(s) Fuel pressure too high or too low

PCV system leak/fault

A/F sensor relay faulty MAF sensor malfunction

ECT sensor malfunction

Air intake restriction

Fuel pressure too high

Fuel pressure sensor malfunction

Fuel pressure regulator malfunction

Note on some vehicles that have been modified this code may be caused by the modifications (e.g. aftermarket exhaust, headers, etc.).

Read more at: https://www.obd-codes.com/p2198

Copyright OBD-Codes.com

 

[Scott88]

SneiderStang, Did you ever figure out what the problem was? I had the same experience the last two times I was out on track? I have an '09 GT500. Both days were hot (95 - 106), and after the second run of the day, I could smell unburned fuel after the second lap. The first day I smelled it, I would pull into the pits as soon as I smelled it. Looked over the car at home checking everything. The second day (last week), I just kept driving and the smell got worse. By the last run of the day, I cut it short because the fumes were so strong. Unlike you, I didn't get any engine codes.

My only clue as to the problem (and it doesn't seem like it is related), is that when I got a custom tune on the car a year ago, the tuner said I was at 99% of the fuel injectors capability. I don't exactly understand what happens when it gets to/past 100%; doesn't seem like it should spit fuel out before entering the engine to create the smell. He gave the impression that I would need to upgrade the fuel injectors before adding anything else that might make more HP. They don't seem related, but with everything else in the car checking out, I don't know where else to look.

Engine Mods: 2.6 pulley & Steeda CAI; stock injectors and everything else.

 

[Dave_W]

I don't exactly understand what happens when it gets to/past 100%

At that point, your input of fuel to the engine can't keep up with the input of air, and the fuel/air ratio goes "lean." That's generally bad, and can lead to things in the engine going bang in very undesirable ways. You should ask your tuner if he meant that the injectors were at 99% "duty cycle" (open 99% of the time when at peak fuel demand) vs. 99% of the injector manufacturer's recommended maxiumum duty cycle (which is usually 80%). Running injectors above the recommended duty cycle can damage them. I'm hoping he meant 99% of 80%.

 

[k98dave]

I agree with good advise from 302 Hi Pro...... start with new 02 sensors as that's what the codes point too.

 

[Scott88]

At that point, your input of fuel to the engine can't keep up with the input of air, and the fuel/air ratio goes "lean." That's generally bad, and can lead to things in the engine going bang in very undesirable ways. You should ask your tuner if he meant that the injectors were at 99% "duty cycle" (open 99% of the time when at peak fuel demand) vs. 99% of the injector manufacturer's recommended maxiumum duty cycle (which is usually 80%). Running injectors above the recommended duty cycle can damage them. I'm hoping he meant 99% of 80%.

Thanks. I'll have to ask him and I hope he remembers. It was over a year ago. I assumed I wouldn't need to worry about it since I don't plan on adding any more mods to increase HP. I told him to keep it conservative, but that might mean something different to everyone.

If the injectors get damaged, do they leak gas?

 

[8bitmime]

I've had the same experience at one our local tracks but I attribute it to using the fuel at the track. If I fill up on that fuel, after the car gets hot (2nd or 3rd session) I start to smell unburnt fuel with no codes at the track. After the car cools down again (either on the drive home or the next day) it'll throw one or both of those codes. The onsite fuel at ECR is 93/100/110 and there is probably more 100/110 sold there so I'm probably getting >93 Octane.

I assume I'm getting stronger fuel and when the air warms up the 93 tune is running rich allowing unburnt fuel vapor to get past the cats. When the car is hot and moving the O2 sensors don't see it but once it cools down a bit and the car is moving slower, the O2 sensors sense the rich condition and throw codes.

 

[xr7]

Another area to watch is the Evap Canister system. I have had a couple of vehicles that ran fine, no codes but would stink of raw fuel at times. The purge solenoids still worked electrically but the vacuum ports were plugged.

 

[Scott88]

Thanks 8bitmime. I had the car tuned in VA with 93 octane. Now I'm in CA where I can only get 91 octane. The first time I smelled gas was on a VA track with 93 octane and 92 degrees out, the second time was on a CA track with 91 and 106 degrees out. It was much worse this last time, but I also ran it longer. Too many variables to be conclusive.

It does make sense though, to a novice like me, that as the Ambient air temp increases (whether from weather or engine bay heat), the car will run richer as there will be less O2. However, this seems common enough that the ECU would just adjust fuel input.

My apologies to Scheider Stang for hi-jacking the thread. Hopefully it okay because we're having (or had) the same problem.

 

[Scott88]

Another area to watch is the Evap Canister system. I have had a couple of vehicles that ran fine, no codes but would stink of raw fuel at times. The purge solenoids still worked electrically but the vacuum ports were plugged.

Thanks. I'll look into that.