Chevy and GMC Duramax Diesel Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hello guys new here. I have a 08 lmm that I did bearings and replaced injectors on. The original engine snapped the crankshaft. I have a white haze and shaking engine at idle and worse when I shift into 5th and 6th gear and hit the pedal. My efi installer put the truck on the computer and we saw that all the inejctor rates were at 0.2 and not fluctuating. I bought these injectors off a buddy that parted his truck out and they all tested perfectly in the old truck. Why would I have all injectors at 0.2 with no change at Accel or in drive? Pressure was 47k if i remember correctly. I did replace the fpr and no change. I took the engine out amd did bearings and took the egr off which was never removed.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #2
Also note I had the same problem with the old engine and I reused the fuel system and harness minus the fuel rail. Same symptoms with that and mileage was 380k on the old engine.
 

·
Former GM Tech and parts
Joined
·
2,519 Posts
Were the flow rates programmed in when the injectors were changed? I'm pretty sure if the flow rates are not programmed in when different injectors are installed that it can make it do some strange things.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #4
I didn't have any programming done but the rates should still fluctuate shouldn't they? Both sets are stock injectors too..I'll have to maybe peel them out and wrote each flow rate down for a dealer
 

·
Premium Member
Joined
·
4,441 Posts
I didn't have any programming done but the rates should still fluctuate shouldn't they? Both sets are stock injectors too..I'll have to maybe peel them out and wrote each flow rate down for a dealer
You need to take it to a dealer or someone with a Tech 2 that can program the flow rates into the ECM and the GPCM
 

·
Registered
Joined
·
1,534 Posts
407driver is corect:


Fuel Injector Flow Rate Programming

Circuit/System Description

The control functions for the fuel injection system are integrated in the engine control module (ECM). Each injector's flow rate information and cylinder position are stored in the memory of both the glow plug control module (GPCM) and the ECM. The fuel injector flow rate programming must be done when any of the following procedures are performed:



  • The ECM is replaced
  • The GPCM is replaced
  • Any fuel injectors are replaced
If the ECM does not communicate, the flow rate information can be retrieved from the GPCM. If both control modules fail to communicate, the fuel injector flow rate information, or injection quantity adjustment (IQA) flow rate numbers, will need to be retrieved from each individual injector.

Before Programming A Control Module

Important: DO NOT program a control module unless you are directed by a service procedure or you are directed by a General Motors Corporation service bulletin. Programming a control module at any other time will not permanently correct a customers concern.

Ensure the following conditions are met before programming a control module:



  • Vehicle system voltage
  • There is no charging system concern. All charging system concerns must be repaired before programming a control module.
  • Battery voltage is between 12-16 volts. The battery must be charged before programming the control module if the battery voltage is low.
  • A battery charger is NOT connected to the vehicle battery. Incorrect system voltage or voltage fluctuations from a battery charger may cause programming failure or control module damage.
  • Turn OFF or disable any of the following systems that may put a load on the vehicle battery:
  • Twilight sentinel
  • Interior lights
  • Daytime running lights (DRL)-Applying the parking brake, on most vehicles, disables the DRL system. Refer to the Owner's Manual.
  • HVAC systems
  • Engine cooling fans, etc.
  • The ignition switch is in the proper position-The scan tool prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
  • All of the following tool connections are secure:
  • The connection at the data link connector (DLC)
  • The voltage supply circuits
  • DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.
Circuit/System Verification

Review the Display ECM & GPCM Inj. Flow Rates parameter with a scan tool. All cylinders should be programmed with a flow rate number. Both the GPCM and the ECM should be programmed with the same flow rate numbers for the corresponding cylinders.

Circuit/System Testing

Important: If the flow rate number is not available in either control module, the numbers will need to be retrieved from each individual injector.

Fuel Injector Identification Numbers









  1. With a scan tool installed, enter the vehicle information and select the following options:
  1. Record all flow rate numbers with the corresponding cylinders from the control modules.
Important: When installing a new fuel injector, ensure that the IQA data number from the yellow IQA Data Tag, shipped with the new injector, is programmed to the correct cylinder



  • If any injectors are replaced, go to Reprogram Injector Flow Rates parameter and enter the flow rate number of the new injector to the corresponding cylinder. The flow rate numbers will automatically update both control modules.
  • If the ECM was replaced, go to Copy GPCM Inj. Flow Rates to ECM parameter and reprogram the ECM. This will update the ECM with the GPCM flow rate numbers.
  • If the GPCM was replaced or the flow rate numbers are not the same for both modules, go to Copy ECM Inj. Flow Rates to GPCM parameter and reprogram the GPCM. This will update the GPCM with the ECM flow rate numbers.
  • If both control modules were replaced, go to Reprogram Injector Flow Rates parameter and enter the previously recorded flow rate numbers or the numbers retrieved from each individual injector, to the corresponding cylinders
 

·
Former GM Tech and parts
Joined
·
2,519 Posts
Exactly what I thought, the flow numbers have to be programmed in to the controllers otherwise the fuel does not get delivered properly
 

·
Premium Member
Joined
·
4,441 Posts
I had an issue with my GPCM, kept throwing a code saying it could not communicate with ECM (P067C). I had to take it to the dealer to have it programmed after replacing it.

The small issue I had is that after he got the balance rates all the same,the CEL was still there with an error code say ing the rates were not correct. The tech told me he had erased the history completely.

I took it home, pulled both Neg battery cables and left them off 30 minutes. When I reconnected them the codes were gone. Apparently he didn't get them all erased.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #9
My issue with that is one they don't have a tag on them so where are the flow rate numbers and second I had the same issues when the factory injectors were still in. Same shaking and haze with raw fuel smell. I was thinking it was the ecm because the efi guy cut the injectors off and it didn't make a difference. The balance rates should fluctuate even with the old injectors programmed am I wrong?
 
1 - 9 of 9 Posts
Top