Turbo6.0L

Once switching to 1 7/8 AR headers has anyone noticed a low RPM surge/chuggle while driving? I have another thread going now with my problems following the header install. Looking to get opinions of actual owners of cars. I am just about ready to go back to stock to see if problem goes away. Have been working with a tuner all summer and have not really gotten anywhere.

Thanks in advance for any help.

spartan8270

Did you get it retuned???

Turbo6.0L

Yes. Worked with one of the vendors on this forum. We were able to pick up a whole bunch of power across the mid range but nothing seemed to help with the surge. While running open loop for MAF tuning the car seemed to run well though.

spartan8270

You may have to have an experience tuner enable VE in the tune and use a combination of MAF and VE. Commonly done to work on the surge issues with big cams also.

Turbo6.0L

Who would you recommend?

ZR1Gerhardt

Just throwing it out there, but maybe your MAP sensor is not working correctly. When it starts to fail, you can see surging. Maybe someone bumped it, or some supporting harness/wire was compromised during the header installation. I am not sure of its exact location on the LS9,so I am speculating. But it could explain why the running has not worked completely.

Scott

Turbo6.0L

Thanks for the help. We have been logging map data all along and have not seen anything funny. I might take another look at all the map sensor data again and see if it all agrees though.

spartan8270

All the tuners ive had experience with are on east coast in the Virginia area. Surging isnt best worked out via remote tune in my opinion but it can be done.

G8Pumpkin

I have been chasing a surge problem at idle for a while and found problems with the connector read my post. If you have Torque plus installed as an obd scan on your phone etc with a blue tooth adapter its about $5.00 for the software and the adapters are cheap you can look at the live gauges and if it shows vacuum on the display then the MAP sensor is talking to the ECU if not you have a connection problem or possibly a bad sensor. Yours is another clue as to the ongoing saga of surge at idle in some and its strange, yours shows after an install of some parts, another puts an MSD intake on and has a problem, me I tried to ad some coils and mine got worse there is a common thread here some where but its being difficult to find. You may have a vacuum leak if you look at the schematic I posted of where the vacuum connections go I found a poor hose between the valley cover and the intake so put some clamps on the hose and mine was a little better, same on the muffler exhaust valve pot at the rear of the car put a clamp on the hose there as that is a direct connection to the back of the intake manifold.

B-Sizzle

I’ve Greg at Kong Performance (check him out on Facebook) remote tuning my car for the past 2 years. Running heads, GP stage 3 cam, headers, e85, etc and it has absolutely no surge at any rpm. Can easily hit cruise control at 1600-2000.

Turbo6.0L

Finally fixed this issue. It was a bad crank sensor. The connector was full of oil. It must have separated internally and let engine oil leak through it into the connector causing signal\connection issues. I tested it off the vehicle and was able to draw water through the sensor base into the connector with a small amount of vacuum.
What led me down this path was that while logging data finally saw the timing drop out during light acceleration. It seemed to be going back to the idle spark table values so it was a huge change you would definitely feel. In some cases it was changing by as much as 20 deg. Before replacing the sensor I used a tech 2 to run the CPK to CMP sensor correlation test per the factory service manual and did not see anything obvious. I was also never able to catch the sensor dropping out using the tech 2 either. Now that the car is running better I might look at the correlation to see if anything changed.

So in summary a $38 crank sensor fixed my issues. All the tuning in the world would not have fixed this but I will likely go back and make sure we are optimized.

B-Sizzle

Wow good catch

Bigjsn250

Agreed, great catch. I am kind of surprised the Tech 2 didn't catch it and there were no codes leading to the sensor.

Turbo6.0L

Yes, not having a code to chase made it much more difficult.

It was even tougher listening to my wife asking me why I had to put headers on a perfectly good car with less than 3000 miles on it and then have this happen.

And now trying to explain to her that it had nothing to do with the headers or the install. Ugh, and I don't think she believes me anyway. At the end of the day she did let me buy a ZR1 though so I am willing to let this slide.