Strange Starting Problem after a track day...... Mark J, please read! :D

[YellowViperSRT10]

Hey Guys,

I just came back from another great weekend at Sebring.... As usual the car ran great, I actually think I drove this car the hardest I ever did, I really drove the **** out of it... I am even seeing cracks develop on our very own Euroteck Drilled/slotted rotors, however it was just matter of time with drilled rotors on the track to crack with the amount of track days I put on these....

Anyway, I finished up my last session of the day, all the temps on the car were showing normal... I started the car up to bring it to my trailer, and when I started it, it started fine, then about 2 seconds after, the revs died down and the car shut off, I started it again, and it did the same. I tried it about 4 times and it still did the exact same thing... So i stared it again, and revived it up a bit to keep the revs up, and then it stayed on fine.... I drove to my trailer, turned the car off.... started it, it did the same thing, start, then a second later the revs died and it shut. Did the same 3 times, so i started it again, and reved it up a bit and it was fine when I loaded it on the trailer.... I had a 3 hour drive home, and was dead tired, so I did not take the car off the trailer that day. The next day I took the car off the trailer and stared the car, and it started fine, just like normal when I took it off the trailer. I started it about 5 times since, and its totally normal.... So obviously I ask, why did this happen? Has anyone else had this issue? Mark J, what do you think?

Thanks in advance guys!

 

[mjorgensen Woodhouse]

I have had this happen to me at a track event also, but it only lasted about 10 minutes? I wonder when the cars are tracked and you are running the snot out of them if the adaptives get learned and the "normal" running parameters are a little "lost" after this? As yours did mine was perfectly fine when it snapped out of it this is why I think what I do, but don't have an exact answer for it.

I will pose this to the SRT guys and see if they agree or have a different take.

 

[Bobpantax]

Hi Mark. Wouldn't one easy way to test the thoery be to disconnect the battery terminal in the front for ten minutes or so at the end of the track day after the symptoms appear; then reconnect and if the symptoms are gone, it would prove your theory about the adaptives.

 

[Tom F&L GoR]

How full was the fuel tank?

 

[GTS Dean]

Be sure to fill the fuel tank and try again.

 

[GTS Dean]

Double post.

 

[YellowViperSRT10]

Funny you guys mention the fuel level, I was going to mention something...... A session before that I added a 5 gallon gas can to the car, and it put the tank on half full which did not seem possible with 5 gallons when it was VERY low! I ran my session, a full half hour and the gas was just above empty when I got back, the reserve light did not go on yet.... The 2nd time I got the car started the gas was still fine, above empty.... The next day when I got home and took the car off the trailer and the car started fine the first time, the car started and the fuel reserve light was on, which seemed strange since it wasn't on the day before and I did not drive the car since... I moved the car and pulled it into my garage, and I see the fuel needle moved up a slightly and the fuel reserve light is not on anymore, and it has not been since I started the car about 5 times since.... Does this have anything to do with it? Was it maybe just to low, and was inaccurate at the time?

 

[MY600HP]

What fuel were you running at the time? Was it race fuel or some ethanol blend? Was it unusually hot?

 

[YellowViperSRT10]

What fuel were you running at the time? Was it race fuel or some ethanol blend? Was it unusually hot?

Just regular 93 octance.... And if you are reffering to the outside temp, yes, it was VERY VERY hot out that day.

 

[SFViper]

Sounds like you have symptoms of "Vapor Lock" . A very common problem, specially after a long, high rpm run in hot weather. I experienced the same thing in my Viper & Audi. When it happened to me, I just pulled over, popped open the hood, ten minutes later I was on my way again.

Here's some information on vapor lock:

Paul Brand: Hemming and hawing mark return of vapor lock | StarTribune.com

 

[YellowViperSRT10]

Sounds like you have symptoms of "Vapor Lock" . A very common problem, specially after a long, high rpm run in hot weather. I experienced the same thing in my Viper & Audi. When it happened to me, I just pulled over, popped open the hood, ten minutes later I was on my way again.

Here's some information on vapor lock:

Paul Brand: Hemming and hawing mark return of vapor lock | StarTribune.com

Wow! I just googed "Vapor Lock" and it sounds like that fits very well! I never even heard of it! So is there a way to prevent this?

 

[mjorgensen Woodhouse]

Wow! I just googed "Vapor Lock" and it sounds like that fits very well! I never even heard of it! So is there a way to prevent this?

Open the hood after each session.

 

[Nyoka]

Wow! I just googed "Vapor Lock" and it sounds like that fits very well! I never even heard of it! So is there a way to prevent this?

Back in the day (1/4 mile) we struggled with vapor lock every summer. Once the problem was diagnosed, "cool cans" were installed between the fuel pump and carbs to cool down the gas (usually attached to inside fenderwell near the rad).

We used coffee cans. The reconfigured fuel line came from the fuel pump, entered the bottom of the can, then coiled inside the can around its inner circumference with coils approx. 1" apart (think of a coil spring on a shock but with much wider diameter). Some racers used rubber hosing (easier to coil); more effective installations took the time to bend a metal line (chilled faster) but in either scenario, entry and exit connections are obviously necessary. The line exited at the top of the can and continued its way to the carb. The fuel line entry and exit points featured rubber bushings and the top of the can was removable. Fill the can with ice and away you go. Slick installations included a small tap, or removable plug, to drain the water after the ice melted.

Not sure if this sort of shade tree mechanic contraption would be acceptable on a road course but it's clean and simple and the worst-case scenario is some water leakage as the ice melts, not unlike a radiator. With an FI engine, some extra work might be needed but the principle (gas is cooled via a longer, coiled fuel line within a cooling station) is sound, and it works.

Today, there may even be aftermarket products specially designed for this problem and/or more flexible fuel line packages that can be shaped easily but still be "chilled". Regardless, the 'cool can' worked very well in hot temperatures with big block MOPARs. Properly installed, it was no more noticeable than the windshield washer-fluid reservoir.