[GunMetalGrey]

After sustained hard cornering on long looping off ramps and on ramps onto or off of the highway my car starts stumbling/lurching/surging with power loss (like it wasn't getting fuel). Then after a few seconds it's fine again.

The dealership replaced the fuel pump and I thought it solved the problem but apparently not...

I had my 1st track day today;

It was going great (considering it rained the whole time) but when ever my gas tank got near 1/2 full my car would start Surging, Stumbling and Lurching (violent power loss) on straight stretches AFTER hard sustained corners at WOT.

The check engine light finally came on by the end of the day.

Thoughts or ideas?

Obviously I'll be booking it into the dealership asap.

[SFV1LE]

Those are textbook symptoms of fuel starvation, which is usually caused by high G turns pushing fuel away from the pump pickup, and the fuel not getting picked up on the far (non pump hanger) side of some tanks that use a weak venturi siphon effect from the fuel return line flow, to suck fuel over the center channel hump.

I haven't heard this is a problem with the ZL1, and I don't think it has this design flaw. My instructor runs his ZLE at max Gs below 1/2 tank and hasn't mentioned this.

But the symptoms occurring only in hard turns, and below 1/2 tank, are textbook fuel starvation symptoms.

[GunMetalGrey]

Originally Posted by SFV1LE

Those are textbook symptoms of fuel starvation, which is usually caused by high G turns pushing fuel away from the pump pickup, and the fuel not getting picked up on the far (non pump hanger) side of some tanks that use a weak venturi siphon effect from the fuel return line flow, to suck fuel over the center channel hump.

I haven't heard this is a problem with the ZL1, and I don't think it has this design flaw. My instructor runs his ZLE at max Gs below 1/2 tank and hasn't mentioned this.

But the symptoms occurring only in hard turns, and below 1/2 tank, are textbook fuel starvation symptoms.

This is what my father thought too.

I haven't seen anyone else mention this on the Camaro forum so I figured it was rare and not some sort of design flaw.

Wish I knew what was causing this so I could get it dealt with asap and I'm hoping the dealership doesn't just do trial and error changes.

What part, if defective, do you think would most likely cause this?

[Aliveguy5]

Mine does not do this at the track either.... I'd get this back to the dealer for a resolution.

[BAD MOOOFOOO]

Is it possible that his gas position sensor is out of calibration and when it shows 'half full' it's really a lot less?

[SFV1LE]

If the ZL1 had this design flaw, it would have quickly appeared on Chevy’s Nurburgring run. The Gs on that lap were incredible and after 7 minutes at WOT it must be nearly empty. I think the car was 100% stock except a racing seat, no fuel cell.

[Markoz28]

I had same issue but in a 73 camaro with stock fuel tank during an auto cross session. Car had complete protouring build except for that. Once I added baffles to the tank it was gone. This should not be happening to the ZL1. It’s a proven track machine.

[breakskeet]

That surging sounds like it could the intercooler pump is cavitating due to air in the system which will then cause IAT to climb and the car will heavily retard timing. This has happened several times to me on the track. Just something to have them check

I don't think fuel pick up is an issue. I have run my car around high G long sweeping turns like turn 17 at Sebring with less than an 1/8 of a tank and never had a pick up problem.

[GunMetalGrey]

Update; took a long hard corner with 1/8 tank of gas left and the car never recovered...

It stumbled choked lurched for 60 seconds until it stalled.

I turned the car off (the electronics were still on) and it did a weird 5 second battery flicker thingy.... I then restarted it and drove it straight to the dealership.

We will see what they come up with...

[kwav8r]

Originally Posted by GunMetalGrey

Update; took a long hard corner with 1/8 tank of gas left and the car never recovered...

It stumbled choked lurched for 60 seconds until it stalled.

I turned the car off (the electronics were still on) and it did a weird 5 second battery flicker thingy.... I then restarted it and drove it straight to the dealership.

We will see what they come up with...

That sounds electrical. Possibly power to the fuel pump being interrupted or a short in a wiring harness that GM is not familiar with.

If I recall correctly, all of the TB work (3 for wiring harnesses) have been completed for your car??

[angryBits]

There are a few TSBs on electrical issues in regards to exposed wiring.

TSB 18258, 17468, 17457.

This happened to my car, I had similar symptoms you describe.
Now the car runs fine.

Beware, when I prompted them about the TSB, they first said "No sorry we don't show any TSBs for your car". I had to push them to visually check the car and hand them the TSB papers before they bothered. I hope this is your issue and that it gets resolved.

[Gunkk]

Originally Posted by angryBits

There are a few TSBs on electrical issues in regards to exposed wiring.

TSB 18258, 17468, 17457.

This happened to my car, I had similar symptoms you describe.
Now the car runs fine.

Beware, when I prompted them about the TSB, they first said "No sorry we don't show any TSBs for your car". I had to push them to visually check the car and hand them the TSB papers before they bothered. I hope this is your issue and that it gets resolved.

Link to the 3 docs.

https://www.camaro6.com/forums/showp...65&postcount=6

[angryBits]

Originally Posted by Gunkk

Link to the 3 docs.

https://www.camaro6.com/forums/showp...65&postcount=6

I'm pretty sure it was 18258 specifically that applied to mine but it doesn't hurt to bring up all three.

[GunMetalGrey]

Originally Posted by angryBits

There are a few TSBs on electrical issues in regards to exposed wiring.

TSB 18258, 17468, 17457.

This happened to my car, I had similar symptoms you describe.
Now the car runs fine.

Beware, when I prompted them about the TSB, they first said "No sorry we don't show any TSBs for your car". I had to push them to visually check the car and hand them the TSB papers before they bothered. I hope this is your issue and that it gets resolved.

Thanks for all the feedback guys, I appreciate the links to the TSB's

Edit/Update*

After reading through those TSB's I'm sure it's something else because it only effect the car after high g corners and not every time or any time the throttle is engaged.

What are the chances of getting multiple defective fuel pumps???

I had to replace the fuel pump in my 2011 SS Camaro and in this 2018 ZL1 and now maybe a 2nd time...