LS2 E40 Throttle Issues

[C10Racer]

I've asked about this previously and received some help but the issues are now worse than ever.

I've got a '73 Camaro running an '05 GTO LS2, LS2 Throttle Body and C5 Corvette Pedal, T56, E40 setup that I've been fighting throttle issues on since we put it together. If you turn the key straight from off and start the car the APPs both act normal but the throttle responds slowly and won't go to 88% (WOT on this setup); it may flash there momentarily but it drops down to roughly 40%. If you turn the key, let the ECU run its prime cycle on the fuel pump, turn the key off and THEN start it-it fires right off and the throttle is crisp and perfect. Now I am occasionally dropping throttle control all together where the APP shows normal but I'm not getting any response at the throttle body. When this happens I get a code p2157 and/or p2127 and nothing we regain throttle body control until I clear the codes. I suspect there is something I've missed in the wiring but I can't fathom what. What wires coming into the ECU actually provide the power and ground into the internal TAC module, I suspect that is as good a place as any to recheck.

[5FDP]

Have you tried using a GTO pedal?

[C10Racer]

Have you tried using a GTO pedal?

I haven't but it's my understanding the C6 (that runs the E40/LS2 Combo is exactly the same? Is this not correct?

[5FDP]

I'd have to look at part numbers to be sure, was just a thought because everything else was from a GTO.

[GHuggins]

What exactly are the parts and tune from - ecm from / pedal from - I know you stated vette, but what year / tune from or based from?

[C10Racer]

What exactly are the parts and tune from - ecm from / pedal from - I know you stated vette, but what year / tune from or based from?

The tune started as an '05 GTO stock tune from the repository, the computer is from an '06 GTO (the original tuner bricked my matching '05 GTO E40), the throttle body is the original donor from the '05 GTO donor the LS2/T56 came from (I've got a spare here we tried that made no difference) and the throttle pedal is ACDelco pn 25835421specced for an LS2 C6. Here in a few minutes I'm going to upload logging from the car so everyone can see the exact issues.

[C10Racer]

Attached are three log files; 1 throttle working engine off, 1 throttle working engine on and 1 throttle not working properly engine on. I also attached the current tune. Thanks folks!

[relicdew]

Main issue I just read was that you have a 2006 E40 ECM with a 2005 calibration written in it. The 2005 E40 must use a 2005 calibration and the same goes for the 2006! So hopefully this 2006 E40 hasn't been compromised!

[C10Racer]

Main issue I just read was that you have a 2006 E40 ECM with a 2005 calibration written in it. The 2005 E40 must use a 2005 calibration and the same goes for the 2006! So hopefully this 2006 E40 hasn't been compromised!

Well the second tuner just went back and looked; the computer the first tuner provided us to replace the one they bricked had an '05 Tune in it when we got it so either she misspoke and it's an '05 ECU or they loaded an '05 tune in an '06 ECU before we got it; is there any way to categorically tell what year an ECU is.

[C10Racer]

Does anyone know what inputs actually provide power and ground to the TAC module in the E40? Maybe I'm still looking at a wiring issue somewhere even though its been checked a dozen times...

[Lakegoat]

Did you use the plug for the pedal sensor that was from the 05 GTO? Or did you wire in another plug?

[Lakegoat]

The sensor number on the gto pedal is 2183453 and has a 8 pin plug if that helps.

[C10Racer]

Did you use the plug for the pedal sensor that was from the 05 GTO? Or did you wire in another plug?

I bought the plug for the '05 Vette from the local dealer and wired it up by the '05 GTO pinout.

[Lakegoat]

I ordered a replacement pedal assembly for my GTO from Au and it took about 3-4 days, but it was about 1/2 the price of the same part here. I think the sensor number on the new onw ends in a 6 instead of 3, but works the same. Maybe you could find a pedal assy here at a junkyard--Ottings might have one?

[C10Racer]

I ordered a replacement pedal assembly for my GTO from Au and it took about 3-4 days, but it was about 1/2 the price of the same part here. I think the sensor number on the new onw ends in a 6 instead of 3, but works the same. Maybe you could find a pedal assy here at a junkyard--Ottings might have one?

I'll look into that; my concern in this case is that I don't understand what would be different? Many places sell the C6 pedal assembly as a kind of "universal" E40 pedal?

[Lakegoat]

I didn't know about the universal fit. I guess if a bunch of people use it, then you don't need to change..

[relicdew]

Your C5 pedal will work just fine, even with a GTO tune. The service number on the back of the E40 ECM will let you know what year it's from.

[scott1995]

Did you ever figure this out I have a swap going with an 06 ls2 E40 with corvette pedal and 4l60, the harness, ecm and tcm all came from PSI and I have the same sluggish throttle 40% max unless I turn the Key on then back off and back on quickly and start it up and then it seems fine?

[Srt8_monte]

https://forum.hptuners.com/member.php?28599-scott1995 Did you ever fix your issue with your LS to swap throttle response I?m having the same issue right now