[ZLRob]

I need to follow up with this thread and give it the update that it needs for anyone looking to do a Katech module.

The JMS booster is indeed THE issue causing my P2635 code. What I didn't notice at the time in the slough of old permanent codes I had stored due to a previous project I was working on in the fuel system was that I had a U042B chassis control module communication failure that has been pending and was the tell that it was the JMS causing my issue.

The moment I eliminated the JMS from the circuit and set it all back to OE connections the codes went away and the fuel system is happy as it once was.

The problem is that the JMS is meant for a single channel fuel pump, and while this is indeed a single channel technically speaking, the Katech Vaporworx controller is connected to the battery and has no way of boosting voltage that the JMS does prior to any boosting at all. I realized it when I hooked up my voltmeter to the JMS and saw that resting static voltage with the car off I was looking at 14.4 volts before doing anything at all. It makes sense now because battery voltage depending what sort of battery you run is going to be anywhere from 12.6- 13.3 volts at rest. So the moment you turn on the car there is a voltage conflict between the two pumps, chassis control communication failure code, and fuel pump insufficient flow code because they are both flowing differing amounts right out of the gate.

Happy modding guys, I'm glad this has been resolved. Fuel system looks great once again!

[KamZL1]

Originally Posted by 2023_ZL1-AUTO

I was told my JMS Voltage Booster was not needed and it was removed when the Katech Dual drop in fuel pump was installed. If fact, I have a used JSM now just sitting on my tool box!

I have 2" kooks, e50, ported mamo tb, tune. How much do i pick up with this JMS. is it worth doing a pulley at the same time? how much then
I know alot of you guys running e have been using this for a loooong time with good results

[2023_ZL1-AUTO]

Originally Posted by KamZL1

I have 2" kooks, e50, ported mamo tb, tune. How much do i pick up with this JMS. is it worth doing a pulley at the same time? how much then
I know alot of you guys running e have been using this for a loooong time with good results

I was running STRONG on E65 with JMS with NO PULLEY.

When I did my X-Port and 2.3 upper, the boost increased so much, I had to start dropping E and eventually it was E5 (almost none). That's when I went with the Katech Dual Fuel pump and Port Injection:

Dyno base line with E5 was 650rwhp and 534rwtq.

Link below is my build, and specifically my JMS mod starts at post # 215

https://www.camaro6.com/forums/showthread.php?t=611982

[KingLT1]

Originally Posted by KamZL1

I have 2" kooks, e50, ported mamo tb, tune. How much do i pick up with this JMS. is it worth doing a pulley at the same time? how much then
I know alot of you guys running e have been using this for a loooong time with good results

It will support more than your high side will with stock cam. If you do a cam with 38% lobe then your fuel system would be equally matched and run out around 770whp on E50-60.

Far as compatibility issues with the JMS. Ran into a similar issue trying to use the JMS combined with a SMG big boy pump. So evidently the JMS must only work with stock pumps because I have tuned a couple cars using a JMS with LT4 pump combined with DSX aux pump and no issues.

[ZLRob]

*sigh* I guess the nightmare project continues... After removing my JMS I took the car out for a drive to go do an errand a few towns away. Went to give the car some throttle over 40% and got stopped up into reduced power/ limp mode. Good thing I had my laptop and scanner with me because I was able to clear it out, but before I did I got a code P2138 Accelerator Pedal Position (APP) Sensors 1-2 Not Plausible, along with a C0242, U0401, and U042B.

After clearing I kept driving and all looked okay. I tried hitting the accelerator again. Same thing. Once I got home and came to test it I tested the TPS on the throttle body. Was able to get 83.9% full open no problem. When I hit the pedal I can't go above either 42.4 or 44% and then at full close the TPS reading goes down to 23%. Doesn't seem normal at all and it almost seems like my accelerator pedal suddenly failed. Just seems weird that I disconnect my JMS and suddenly I'm getting all these dumb issues.

Are pedal failures common on these? I have searched and don't see a lot, but it was also like 2 am and wasn't in the right state of mind to look into this. Dealer wants some $500-$600 for a pedal assembly which is absolutely insane.

[RobZL1]

Any chance you pulled something loose in the wiring harness at the pedal when you removed the JMS harness?

[Rapid_blue_zl1_22]

Originally Posted by RobZL1

Any chance you pulled something loose in the wiring harness at the pedal when you removed the JMS harness?

This was my thought as well. If the JMS was wired into the accelerator pedal, then maybe the wire was cut (Fully or partially) while removing it. Especially if a wire tap was used to install it. I have seen those cause so many wiring problems.

[ZLRob]

Originally Posted by RobZL1

Any chance you pulled something loose in the wiring harness at the pedal when you removed the JMS harness?

Originally Posted by Rapid_blue_zl1_22

This was my thought as well. If the JMS was wired into the accelerator pedal, then maybe the wire was cut (Fully or partially) while removing it. Especially if a wire tap was used to install it. I have seen those cause so many wiring problems.

The harness was intact and never modified because I used JMS's pass through wiring harness. Everything was fully functional prior to pulling the actual JMS harness to the FPDCM itself. I left the pass through wiring harness to the pedal in place for sake of just doing less during de- modification. I pulled the wiring afterwards to see if the JMS setup itself was causing issues and the issue persisted. The wiring to the pedal itself has never been abused or tugged on excessively hard or anything that would cut it/ damage its connection to the accelerator pedal.

I've got a Soler throttle body and though it tested out okay on HPT, Katech suggested trying my OEM original to rule it out.

I just can't understand how a throttle body would suddenly go bad from one moment to the next though. Same with the accelerator pedal.

[2023_ZL1-AUTO]

Any change that a PIN in the wiring harness has been affected possible a PIN misalignment or anything as such? I agree to try the stock TB, but that would not make any sense. If you need to try another Soler, I have 100mm collecting dust, I could ship it to you for testing. PM me if you are interested in a loaner for testing!

[ZLRob]

Originally Posted by 2023_ZL1-AUTO

Any change that a PIN in the wiring harness has been affected possible a PIN misalignment or anything as such? I agree to try the stock TB, but that would not make any sense. If you need to try another Soler, I have 100mm collecting dust, I could ship it to you for testing. PM me if you are interested in a loaner for testing!

Thanks for the offer brother. I'll let you know. I gotta try out my OE TB and see how it goes. It doesn't help that these cars have become incredibly more complex with their CAN BUS network stuff.

Just weird because prior to even touching the pedal's wiring whatsoever everything was totally fine. Then all of a sudden the car is going haywire the moment the JMS gets disconnected, not even related to anything throttle body and accelerator pedal related.

[2023_ZL1-AUTO]

You had to splice your wire and intercept it at the FPCM right? Is there a change that connection is not solid and needs "redone" ?

[ZLRob]

Originally Posted by 2023_ZL1-AUTO

You had to splice your wire and intercept it at the FPCM right? Is there a change that connection is not solid and needs "redone" ?

No what I did at the time during the JMS install was I took the same female and spade terminals and depinned the connector itself at the FPDCM plug and inserted those in place to be the new terminals at the plug then heat shrunk everything weather tight so there was never any need to cut or splice anything. It was a very reversible, very clean install.

I spoke with Mike at Soler and he said the code is typically not related to the throttle body, but obviously do not discount it out of possibilities. He suggested first disconnecting the battery and leaving it disconnected for 5- 10 minutes so it would totally clear any keep alive values retained within the PCM. It would make sense that after removing the technically "load" out of the circuit that you may need to do a full clear out to reset all learned and retained values to zero. It was something I thought of but didn't necessarily see the need in doing, though looking back at it all it should have been one of the first things I did before chasing possible ghosts in the setup.

If not, he suggested logging APP 1 and 2 parameters and seeing how they behave in HPTuners as the pedal is swept through. If the values do not go up and down respectively independent on both channels as a constant value then the pedal is indeed defective and this was all just a freak accident/ defect occurrence and will need replacing.

[18.2SS.1LE]

Originally Posted by ZLRob

*sigh* I guess the nightmare project continues... After removing my JMS I took the car out for a drive to go do an errand a few towns away. Went to give the car some throttle over 40% and got stopped up into reduced power/ limp mode. Good thing I had my laptop and scanner with me because I was able to clear it out, but before I did I got a code P2138 Accelerator Pedal Position (APP) Sensors 1-2 Not Plausible, along with a C0242, U0401, and U042B.

After clearing I kept driving and all looked okay. I tried hitting the accelerator again. Same thing. Once I got home and came to test it I tested the TPS on the throttle body. Was able to get 83.9% full open no problem. When I hit the pedal I can't go above either 42.4 or 44% and then at full close the TPS reading goes down to 23%. Doesn't seem normal at all and it almost seems like my accelerator pedal suddenly failed. Just seems weird that I disconnect my JMS and suddenly I'm getting all these dumb issues.

Are pedal failures common on these? I have searched and don't see a lot, but it was also like 2 am and wasn't in the right state of mind to look into this. Dealer wants some $500-$600 for a pedal assembly which is absolutely insane.

I have the stock pedal off my car I could ship you for the cost of shipping.

[RobZL1]

Originally Posted by 18.2SS.1LE

I have the stock pedal off my car I could ship you for the cost of shipping.

But how would you drive YOUR car?

Just kidding.

But seriously, is there some whiz bang aftermarket pedal that adds 200hp or modifies the stock pedal progression or something? I didn't know there were pedal replacement options out there.