LS3 376CID 480 HP CRATE ENGINE 19301358 have lost 100hp

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Ponrov
Posts: 58
Joined: Mon Oct 17, 2005 11:58 am
Location: Norway Chevy 97 K1500 SCSB,. Pontiac Firebird Formula 72 400. Range Rover 77 Land Rover seri1-88 56

LS3 376CID 480 HP CRATE ENGINE 19301358 have lost 100hp

Post by Ponrov »

Hello I need some help/advice
A friend of me have a 1970 Camaro with 480hp Ls3 it has only 380 at the rear wheel. The controler is the
19258267 - GMPP LS376/480 CONTROLLER KIT.
We has mounted logging equipment to OBD port (bluetooth obdlink android) what we found was that the O2 sensor 1 varies between 0.09-0.8V
and O2 sensor2 showing 0,45 v constant , have tried to change sides of the sensor.
He have some problem in the begining with some fals air legage, can this have made some problem for the controler is
there som way to reset /relearning the contoler.
Where can I find wiring diagram for this.

Best regards Ponrov

Speeder
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Joined: Fri Apr 30, 1999 9:12 pm
Location: 2021 Dodge Durango R/T 2WD, 2008 Colorado work beater, 2003 Dodge Dakota pro-touring project

Post by Speeder »

Hey there. Yes, air leakage will cause problems. You want the computer to know exactly how much air is coming in, because it bases its calculations off how much air is measured.

Ideally you want the O2s as close to the headers/manifold as you can get them. It won't hurt if the car's layout forces you to put them further back, but the closer the better.

To reset the ECM, if nothing else, you can disconnect the battery overnight. 15 minutes may be enough but you will get a total reset overnight.

The one sensor that reads a constant .450 has an open in the wiring somewhere. Either the ground is bad or the signal wire is bad. The other one is reading rich. 0.450 is the crossover point, but it should be crossing over and not a constant number.

On the HP rating, that is measured at the flywheel, not at the rear wheels, as the manufacturer can't know what is between the flywheel and the rear tires. 380HP at the rear wheels shows that you have a 21 percent driveline loss. So, I don't think your friend has a huge problem since typical driveline losses are around 15-18 percent. I think once your friend works out his O2 sensor problems that he will pick up the missing 5 percent. Good luck.

Hog
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Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

What trans rearend and tires is your friend using?

I would have to say that your 380 rwhp isn't far off depending on what equipment you are using.

The O2 sensor voltages you have quoted, are they at WOT or cruising?

The 480 hp LS3 is simply a crate LS3 wit the GEN 3/4 219º/228º 0.525"/0.525" 112ºLSA Hotcam installed. They offer a 525hp version as well, it has the ASA 226º/236º 0.525"/0.525" lift 110º LSA cam installed.

Seeing as these are both cammed engine packages, your induction and exhaust has to be PERFECT to get the quoted numbers.

Don't be too concerned with actual chassis dyno numbers, when doing mods, concern yourself wit hteh gain or loss of those numbers, the chassis dyno is simply a tuning tool. For accurate engine output, the engine dyno reigns supreme.

peace
Hog

Ponrov
Posts: 58
Joined: Mon Oct 17, 2005 11:58 am
Location: Norway Chevy 97 K1500 SCSB,. Pontiac Firebird Formula 72 400. Range Rover 77 Land Rover seri1-88 56

Post by Ponrov »

Thank you for your feedback

Finish line trans 4L65/70E-5 Extreme Duty – Level 5 , Precision Industries "Vigilante" 9.5" Lockup 3 disk, rear end ford 9" 31 splins diff. eaton trutrack 3.89 Gear Ratio ,11" Explorer Disc Brake Kit

O2 sensor voltage is idle, sensor2 ihave no respons is still at 0.45 V. I need to mesure on the wiring at the sensor and see it get som voltage.(wish I have a wire diagram)

one told me that the control goes in emergency mode if a sensor malfunction, where it goes into open loop which adjusts to later ignition and gives more fuel

engine mod is Edelbrock headers and 2.5" dual exhaust with x crossflow , intake is 4" 90deg bend to the intake then a stright on with MAF then a KN filter.

One thing I think have reduse som power is the Car Chemistry Exhaust Inserts he have mount right after the headers.

Best regards Ponrov

z71gmc06
Posts: 1013
Joined: Tue May 08, 2007 12:45 pm
Location: Michigan

Post by z71gmc06 »

Sounds like a pretty well thought out build. Some nice heavy duty parts there for sure.

Hope you get it sorted out. We need pictures of course.

Speeder
Posts: 10763
Joined: Fri Apr 30, 1999 9:12 pm
Location: 2021 Dodge Durango R/T 2WD, 2008 Colorado work beater, 2003 Dodge Dakota pro-touring project

Post by Speeder »

One place to check is the wiring harness as it goes from the engine to the transmission. It's easy to get a wire or three pinched between the two, and the O2 sensor wires will be in the bundle that goes down the back of the engine and transmission.

Hog
Posts: 5025
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

I also might check the actual voltages coming off of the O2 sensors. This could simply be an issue with your scan tool not recognizing the 2nd o2 sensor.

When you swapped O2 sensors, did the 2nd O2 sensor work when you installed it into the 1st position?


Does sound like a well thought out system. With the torque converter you are using, it will "absorb" more power than a stock torque converter will. Unless you did your dyno pulls with the TC clutches locked.

peace
Hog

playtoy_18
Posts: 1904
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Location: oklahoma

Post by playtoy_18 »

To be sure,is it 02 sensor 1 and 02 sensor 2 you are looking at?
Sensor 2 (bank 1 or 2) should always read constant if your using cats.
Sensor 1 is fueling,sensor 2 is the cat monitor.
Bank 1 sensor 1 and bank 2 sensor 1 is what you should be monitoring.
If you have cats,then sensor 2 is the after cat monitor for convertor efficiency.

Hog
Posts: 5025
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

playtoy_18 wrote:To be sure,is it 02 sensor 1 and 02 sensor 2 you are looking at?
Sensor 2 (bank 1 or 2) should always read constant if your using cats.
Sensor 1 is fueling,sensor 2 is the cat monitor.
Bank 1 sensor 1 and bank 2 sensor 1 is what you should be monitoring.
If you have cats,then sensor 2 is the after cat monitor for convertor efficiency.
You are correct, but I don't think these GMPP kits have the emissions calibration on the ECM's. Thus cat monitoring isn't included.
I assume he is referring to Bank 1 and Bank 2, or Cyls 1,3,5,7 and Cyls 2,4,6,8?

peace
Hog

Ponrov
Posts: 58
Joined: Mon Oct 17, 2005 11:58 am
Location: Norway Chevy 97 K1500 SCSB,. Pontiac Firebird Formula 72 400. Range Rover 77 Land Rover seri1-88 56

Post by Ponrov »

Hello regarding the Rear wheel HP mesuring it was 305 hp not 380 hp

The sensor is O2 sensor 1 and O2 sensor 2, the one on the Left side is working going up and down between 0,09 v to 0,80 v, the one on right side sensor 2 stand still on 0,45v We try to switch the to sensor but i where the same.I have tryd this program on My pickup truck there it`s working same on boht side.

The owner of the Camaro have have found a connection diagram on Internet, one of the first day we going to measure the wiring .

best regards Ponrov

Speeder
Posts: 10763
Joined: Fri Apr 30, 1999 9:12 pm
Location: 2021 Dodge Durango R/T 2WD, 2008 Colorado work beater, 2003 Dodge Dakota pro-touring project

Post by Speeder »

If switching the sensor from side to side showed no change, you are looking at wiring harness damage. I'd be willing to bet that you will find the wiring is pinched between the engine and transmission, or the harness has gotten against the exhaust somewhere. Aside from that, you are running rich according to the other side. When the wiring is corrected, you can correct the rich condition. For that, I would start by verifying that the engine size is correct in the computer. EFI Live will also allow you to connect a wideband sensor for proper tuning.

Just to verify though, you are looking at sensor 1,1 and 1,2 for the fronts, and sensor 2,1 and 2,2 for the rear sensors, for a total of 4 sensors. I know there is a language barrier to overcome here, and we want to make sure there is no misunderstanding between us on the sensor names.

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