LT4 Crate engine manual trans cal.

I have been dealing with a throttle hanging issue that myself and several of my tuner friends could not find the cause or solution to on an LT4 crate controller. I finally got some answers directly from GM. Apparently since I purchased my LT4 crate harness and ECM, there have been changes. At the time there was only one part number. Now there are two part numbers, one for auto and one for manual. GM will only tell me that the harness is different and they claim that I cannot plug in a manual E92 ECM into my current harness. I am looking to see if anyone has a stock crate LT4 manual cal that they would be willing to share with me so I can just give that a shot before I try to get GM to correct the problem with new hardware. Thanks!

so the harness you have is for auto do you have the transmission harness 8l90?

ask them to send you the file they use in their calibrations

Jarrah, I have a T56. GM is unwilling to share a cal. One reason being they don't use HP tuners. The harness I have was what they sold for both a manual and an auto at the time, but it seems to be geared toward a manual because it has clutch pedal leads. From my conversation with GM, there must be some sort of patch in the cal and possibly the harness for the throttle issue I'm experiencing. Sounds like it stems from the loss of active rev match and supporting hardware. From what I can tell, along with several tuners I have talked to directly, whatever has been changed must not be accessible in HP Tuners. Because GM has told me what the problem is, but won't/can't share the info, that's why I'm looking for someone who has a more recent connect and cruise cal to start there. I've compared my crate motor cal to a stock Z06 and none of the differences point to a throttle issue.

What part number system did you purchase?
GM has a few different versions now because they changed the engine being sold.

The older version was used with the analog fuel pressure sensor (4 wire)
The new version is used with the digital fuel pressure sensor (3 wire)
The cals can not be swapped with out an OS change.

I might have the version you are looking for.
-Greg

radrace19, I have controller 19331517, which has been superseded to 19370326 according to the GM tech representative. I believe the fuel pressure sensor I'm using is 13579380 which is a 3 pin. I'll have to get under the car and unplug it to be certain. Thanks for your help!

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Originally Posted by 78bronzechariot

radrace19, I have controller 19331517, which has been superseded to 19370326 according to the GM tech representative. I believe the fuel pressure sensor I'm using is 13579380 which is a 3 pin. I'll have to get under the car and unplug it to be certain. Thanks for your help!

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The fuel pressure sensor in question is the fuel rail pressure not the feed pressure.
19331517 is superseded to 19368841.
The 19370326 is the digital fuel pressure version that will not work.

The 19331517/19368841 is for the analog rail pressure sensor.
I have a read from the older version (19331517), but not the updated (19368841) version.

-Greg

I take that back. I can get you a full read from the 19368841 kit ;)
-Greg

Thanks for your help Greg!

can you post the tune greg over here

Sorry I forgot I had an appointment yesterday I had to get to.

Here is the file from the newer version. There doesn't look to be any differences.
LT4 19368841 calibration

-Greg

Thanks Greg, HP tuners support indicted that there are tables in the E92 that aren't supported yet. I'm hoping that there is a change on one of those potentially hidden tables that may affect this issue.

Have a friend with a swapped 16' LT E92 with hanging throttle issues as well, anything over 3000 rpm or so it hangs there for a solid 2 seconds. Hopefully there's tables to resolve it soon.

Hi all,

I have bought a LT4 crate engine with a 8L90 transmission.
But I have some issues and nobody can help me, also I am outside of the US and GM performance will nog give any support to people outside the US.
so maybe you can help me.

can someone give me a picture or a log file of the Fuel pressure graph, my fuel pressure not steady at idle.. is swings from 3 to 4 bar

the engine controller harness for a A/T comes with a clutch wire, but in the install guide it says "Top of Travel Clutch Switch/Brake Switch"
does anybody connected this? because I did but the brake status is always "yes" in the VCM scanner.

so I wanted to do the "fast learning" procedure for the 8L90 transmission.. but the scanner is waiting for me to press the Brake ha ha.

last but not least would it be possible that the tap tip/down switch will not work if the brake status is "yes"
I can also imagine that the transmission now prevents to go in lockup...

so for me... it was not plug and play ha ha.

any input would be very helpfull

thanks

Anyone found a fix?