Throttle lag, list of codes, help!

[MURPHDIESEL]

Hey guys, need some help. I'm having issues with my LLY and I can't figure it out. 2 weeks ago I replaced my water pump, and after I was done the truck seems to have issues (I don't think it's related.)

When I step on the throttle, the truck seems to fall flat on it's face, take a few seconds, then it will build boost and take off. But it feels like it's 20-30% less power. There use to be a small puff of black smoke when I would take off and it would clear up quick, but now there is nothing(not complaining, just out of the ordinary.)

it seems like I have really bad turbo lag, like the stock turbo isn't even lighting, and I'm waiting for the second turbo to spool.

Here is a list of codes that I'm getting-

B2575 head lamp low beam circuit
P0621 batteries not charging
C0040 Right Front Wheel Speed Sensor Circuit
B2610 Passenger Compartment 1 Dimming Circuit
P2138 Throttle/Pedal Pos Sensor/Switch D / E Voltage Correlation
P2140 Throttle/Pedal Pos Sensor/Switch E / F Voltage Correlation
C0035 Left Front Wheel Speed Sensor Circuit
B2961 Key in Ignition Circuit BCM DTC B2961
U1000 Class 2 Data Link Malfunction
U1160 Lost Communications with Driver Door Module

The truck has a MPI compound turbo setup over the stock charger, ATP Truck tuning, stage 4 trans from Mike L, and a few other upgrades that I don't think are relevant to this issue.

I'm wondering if something happened to the PCM when I was swapping out my water pump? Only thing I could think of....

Any help is greatly appreciated guys!

 

[andy-stevenson]

Have you checked the wires by the ficm and alternator?

 

[MURPHDIESEL]

Have you checked the wires by the ficm and alternator?

Thanks Andy, I've checked that known potential issue in the past and made sure it was not rubbing, but I will definitely give it a second look today.

My first thought was that I had either a air or fuel issue. I checked and cleaned the MAF, checked for any boost leaks. Checked the rail pressure and the actual vs desired seem normal. I bought some new fuel filters to install today, but I'm thinking that's not going to help.

I'm going to look over all the harnessing in the engine compartment and check all the connectors to make sure something didn't get messed up when I was in there swapping the water pump.

If anyone has any other ideas please feel free to chime in, any help is appreciated!

 

[MURPHDIESEL]

I wanted to revive this thread as I am STILL having this issue and really need some help!

The trucks still runs and drivability is ok. Just wont get out of the hole to save it's life.

Here are some more solutions I have tried, as I'm really leaning towards it being an electrical issue.

• Opened up almost the entire engine harnessing and checked for any shorts or nicks.

• Replaced the MAP sensor

• Cleaned all harness bulkhead connections and checked the pins and sockets for any recessed.

• Did some data logging with EFI Live, everything seemed to be working (from what I can tell, not very knowledgeable with the scan tool)

• Checked the throttle position (since I keep getting the P2138 and P2140 DTCs) and it seemed to be reading correctly. From what I've read, these codes are common when you have the BT Lockbox.

The most recent attempt to fix it was replacing the MAF. First test drive after replacing it the truck ran amazing! Back to normal! Second drive in the truck and its back to lagging really bad, slightly worse now! And it’s been this way for the last few days now. So I check the harnessing from the MAF sensor, tracing each wiring to it’s end to try and find a short. I also check each wire from end to end with an Ohm meter to see if there was any resistance change, each checked out fine.

So now I don’t know where to go from here… I’m afraid to put another MAF in and it go bad as well, they aren’t that cheap to keep replacing.

One thread I read with a similar issue, they checked and cleaned all the engine ground connections and fixed it. So I’ll give this a shot, but I doubt it will help. A while back I added a ground cable from the battery to the engine, and a second one from the block to the frame.

Any Input on what to do next is greatly appreciated, sorry for the long text. I hope I explained it clearly.

I’m ready to take it to a knowledgeable shop/garage that can figure it out for me. I’m in the L.A. area and willing to travel somewhat if needed. I’ve asked around with very little luck or confidence on any shops near me.

Thanks in advance!

 

[PureHybrid]

Any trucks close that can swap a MAF sensor with you? Could always throw the old one back in, if it runs good for a while its probably that connector or the wires.

You could always tell Rob to max out the MAF tables in the tune. It will smoke like crazy (maybe) but if it spools up and drives fine, that'll pin the problem on the MAF circuit.

 

[bmc1025]

I think you are on the right track cleaning grounds. I had a truck that was doing something similar but it would show all kinds of maxed out readings in the scan tool. It ended up being a loose fitting fuse I think it was the ECM B fuse but not 100 percent sure. The tabs that hold it in were spread from someone previously using a fuse tap but had since been removed.