Help with warm start issue - Whipple

[khsonic03]

Hi All,

Been battling with a warm start issue since I installed the Whipple in January this year.

It is most reproducible after I drive the car for about 5 minutes, park it, then start it after waiting 10 mins.

The engine will start up, then drop RPM quickly to 500rpm, then flutter, then stabilize once the o2 sensors come online. You can actually hear the TB making a thump sound when it drops RPM quickly.

Issue is noticeably worse with the AC on when starting.

Car drives perfectly otherwise. Cold starts are fine (used to have similar issues with them but the tuner was able to work those out).

Hoping someone who is good with data logs/tuning can take a look at the attached file. This is a warm start with the AC on. LOG FILE

Reputable tuner has been great in trying to fix it (super nice and very willing), but has been unsuccessful so far. It seemed to be fine for a bit, but then I recently had the battery disconnected for about a day and it went back to warm starting like shit (KAM got erased and screwed up the tune somehow?). I have since put about 100+ miles and 15+ starts on it.


Mods:

• 2017 GT
• Gen 5 Whipple
• 3.875 pulley (11psi)
• 132mm TB
• Oversized Heat Exchanger
• ID1050X
• NGK 6510 gapped to .028
• JMS BAP
• 170 degree thermostat
• 1 7/8" long tubes - catless

Things I've tried so far:

• Checked TB TP2 voltages and dialed into spec
• removed TB gasket and replaced with RTV to help prevent sticking
• Flashed back to stock and then reloaded tune
• Tried to locate a vacuum leak - unable to find anything
• Replaced evap purge valve
• Removed catch can and replaced with regular hoses to ensure no vacuum leaks

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[Jdown]

Hi All,

Been battling with a warm start issue since I installed the Whipple in January this year.

It is most reproduceable after I drive the car for about 5 minutes, park it, then start it after waiting 10 mins.

The engine will start up, then drop RPM quickly to 500rpm, then flutter, then stabilize once the o2 sensors come online. You can actually hear the TB making a thump sound when it drops RPM quickly.

Car drives perfectly otherwise. Cold starts are fine (used to have similar issues with them but the tuner was able to work those out).

Hoping someone who is good with data logs/tuning can take a look at the attached file. LOG FILE

Reputable tuner has been great in trying to fix it (super nice and very willing), but has been unsuccessful so far. It seemed to be fine for a bit, but then I recently had the battery disconnected for about a day and it went back to warm starting like shit (KAM got erased and screwed up the tune somehow?). I have since put about 100+ miles and 15+ starts on it.


Mods:

• 2017 GT
• Gen 5 Whipple
• 3.875 pulley (11psi)
• 132mm TB
• Oversized Heat Exchanger
• ID1050X
• NGK 6510 gapped to .028
• JMS BAP
• 170 degree thermostat
• 1 7/8" long tubes - catless

Things I've tried so far:

• Checked TB TP2 voltages and dialed into spec
• removed TB gasket and replaced with RTV to help prevent sticking
• Flashed back to stock and then reloaded tune
• Tried to locate a vacuum leak - unable to find anything

Did you try the crank relearn?

 

[khsonic03]

Did you try the crank relearn?

That's one thing I haven't tried yet. From what I had researched, it wouldn't need to be done unless I replaced the clutch/flywheel.

Also would have thought that would impact the way the car runs/drives overall vs. just during startup.

Thoughts?

 

[Jmtoast]

I had that issue when I used boostane. Different kit, different tune, but same exact issue.

 

[khsonic03]

I had that issue when I used boostane. Different kit, different tune, but same exact issue.

Ah shit. Well I do use boostane, so hmmm.

Did you stop using boostane and it went away? Or were your plugs fouled or something?

 

[Jmtoast]

Ah shit. Well I do use boostane, so hmmm.

Did you stop using boostane and it went away? Or were your plugs fouled or something?

it started happening as soon as I started using boostane and stopped when I stopped using boostane. I only used it for a couple weeks.

 

[Dominant1]

Have you considered replacement the throttle body gasket with gasket sealer material. Ive read where plenty have solved these type of issues by dumping the whipple throttle body gasket..

 

[khsonic03]

Have you considered replacement the throttle body gasket with gasket sealer material. Ive read where plenty have solved these type of issues by dumping the whipple throttle body gasket..

Yes. That's one of the things I tried early on. Unfortunately didn't help.

 

[TX-Ripper]

who’s tune up?

 

[khsonic03]

who’s tune up?

One of the major 2.

 

[Dominant1]

The Major 2 being, Lund and Palm beach dyno..

 

[TX-Ripper]

Look at your short term fuel trims...

(You might have a vacuum leak)

 

[khsonic03]

The Major 2 being, Lund and Palm beach dyno..

Thats correct.

 

[khsonic03]

Look at your short term fuel trims...

(You might have a vacuum leak)

I'm not experienced with tuning, so I'm not sure what I should be looking for.

 

[khsonic03]

I have looked for a vacuum leak, but haven't been able to find anything.

If I had a vacuum leak, wouldn't I lean out during WOT as well?

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