Gen 2 track problem

[Arizona Vipers]

Hi guys,
I've got a 1997 GTS track car. When it gets hot (always happens starting with the 2nd, 20 minute session) the car will act like it's hitting the rev-limiter, but at random RPM's. This happens only at wide open throttle and only when the engine compartment is very hot. The car will pop and sputter, over and over while under full throttle. I can still drive the car and finish the track session, but power is lost under WOT.
I'm ruling out anything on the motor itself as I had a new engine installed and the car still has the exact problem (only worse now as the new motor has more power and heat) This is driving me crazy as it's ruined the last 4 out of 7 track events. I've got a few ideas from Eddie Martin, JonB and Roe, but maybe somebody out there has experienced this exact problem in the past and knows what it is. This is getting expensive to fix as the problem cannot be duplicated unless on the track.

Thanks!

[Fatboy 18]

What Headers are you using, are they wrapped?

What intake system are you using?

Do you have a pic of the Engine bay?

Its Very hard to offer any advice without knowing your set up :)

[99RT10]

Does the car still have cats installed?

[Martyb]

You have a fuel pressure gauge? My old car did this, ended up being the fuel pump.

[Arizona Vipers]

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What Headers are you using, are they wrapped?

Belangers, not wrapped. (straight pipes that exit mid-door)


What intake system are you using?
Smooth tubes, K&N's


Do you have a pic of the Engine bay?
Please see attached pics. Let me know if you want something specific

[/QUOTE]

- - - Updated - - -


Does the car still have cats installed?

No, straight pipes that exit mid-door

[Arizona Vipers]

You have a fuel pressure gauge? My old car did this, ended up being the fuel pump.
When you had this problem, did it ONLY happen when the car got really hot?

[Dan Cragin]

Check the throttle position sensor, does it throw a code for Map does not agree with TPS?

[Martyb]

When you had this problem, did it ONLY happen when the car got really hot?

Strangely enough yes, ran fine until it heated up. It was a Walbro pump, and I was told they had a bad batch of them(this was years ago). I chased it for a while, then decided to hook up a fuel pressure gauge and saw it immediately.

[Arizona Vipers]

Check the throttle position sensor, does it throw a code for Map does not agree with TPS?

Hi Dan, here are the codes it's throwing right now ( I didn't have my code scanner with me at the track that day)

P0443 Evaporative Emission Control System Purge Control Valve

P0141 Oxygen O2 Sensor Heater Circuit Malfunction (Bank1, Sensor2)

P0161 - Oxygen O2 Sensor Circuit Low Voltage (Bank2, Sensor2)

P0138 - Oxygen Sensor Circuit High Voltage (Bank1, Sensor2)

P0158 DTC code which refers to a high voltage in the number 2 O2 sensor circuit on bank 2

P1495 EVAP Leak Detection Pump Solenoid Circuit


Thanks!

[Arizona Vipers]

Strangely enough yes, ran fine until it heated up. It was a Walbro pump, and I was told they had a bad batch of them(this was years ago). I chased it for a while, then decided to hook up a fuel pressure gauge and saw it immediately. I just ordered a Walbro 400! Hopefully it fixes it, but still want to hear everyone else's ideas!

[GTS Dean]

I had a similar sort of problem with my 96. Under hard accel at the track, the motor would just switch-off for a split second and then light up again. Had my JTEC re-flashed and the problem went away.

[Arizona Vipers]

Had my JTEC re-flashed and the problem went away.

I don't think it's this because I had the problem before and after I had my car dyno tuned..

[stuntman]

What fuel pump are you running?

[Fatboy 18]

It might be nothing to do with it but I would fabricate up some heat shields for the headers. It might help some?

Strange things happen when things get hot!

[XSnake]

Put the factory header heat shields back on the car if they are off.

[Arizona Vipers]

What fuel pump are you running?
I'm not sure what's in there now, but bought a Walbro 400 LPH from Roe and plan on installing it before next track event just for the hell of it.

[Arizona Vipers]

Put the factory header heat shields back on the car if they are off.
They are there, but I'm wrapping the headers right where they run underneath the shield as well as putting this product on both sides of the heat shields- http://www.thermotec.com/products/13500-adhesive-backed-heat-barrier.html

What do you think this would help with? Do you think the engine wiring harness that runs through there could be the problem or the computer itself close to that area?

Thanks!

[Arizona Vipers]

What Headers are you using, are they wrapped?

)

Do you suggest I wrap the entire headers top to bottom?

[Fatboy 18]

Looking at the pictures you posted there are no heat shields, that is why people have suggested you put the oem heat shields back OR Wrap the headers down as far as the collectors.

What sort of outside temperatures are you running the car in? :)

Caution : According to the Belanger fitting instructions, Wrapping the Headers will destroy the Tubing and the Coating!

[Arizona Vipers]

Looking at the pictures you posted there are no heat shields, that is why people have suggested you put the oem heat shields back OR Wrap the headers down as far as the collectors.

What sort of outside temperatures are you running the car in? :)

Caution : According to the Belanger fitting instructions, Wrapping the Headers will destroy the Tubing and the Coating!


I track the car here in Arizona, so it's always hot. I've done morning events in the summer where it's 90* at 6AM and 105* by 11. Even in the winter it's mid 80's. The problem always gets worse the hotter it gets. At this point, I'm leaning towards wrapping the entire headers. If they corrode and I have to replace them every couple of years so be it. At least I'll have a car that doesn't let me down at every track event. Thanks!

[stuntman]

Why not just put the factory heat shields back on? Seems like the easiest solution.

[2Luke2]

Almost sounds like an older carb car boiling fuel.

[Arizona Vipers]

Another thing I forgot to mention which started happening as well, after a track session the idle speed will be high, around 2000 RPM. But by the time I start it up for next session the idle is normal. I'm not sure if this is related or not...

[WDW MKR]

Why not just put the factory heat shields back on? Seems like the easiest solution.

Will they fit with the Bellangers? I know they don't with ARH.

[Mad Max]

Yes they will fit. I have Ballangers with the OEM heat shields installed. A slight amount of tweaking of the shields required however it works fine and does help. I did this after melting the under side of the airbox for the HVAC.

[Lemay88]

I noticed on you OBDII codes that the O2 sensors were reported...I had the same engine problems when my O2 sensors were faulty. Changed them and no more pop and spotter...
Just my 2 cents

Ben
1997, R/T10, stock

[ViperGeorge]

Had a similar problem on a different car. Changed everything. Ultimately discovered that fuel returning to the tank was being heated by the hot engine. Fuel in the tank was getting too hot, once it exited the fuel tank heading back to the engine it was vaporizing and creating bubbles in the fuel supply. This caused the engine to run poorly.