[shinysun]

I am using a BAP from JMS, but recently I saw the below



What is this meaning?

17.5 voltage which I am using is dangerous to my system? F35 Fuse? Or the fuel pump itself?

[TJay74]

Fuel pump itself, I have a JMS box and found this out recently. I bought it up to JMS and they said they hadnt heard of any issues. With in 3 months of adding the JMS to my system my LPFP was burnt up and I had to replace it, lucky it was under warranty,

As soon as the new pump was in the car I backed the JMS back down to 16.2v and then I put the fuel pump voltage in the tune to the 15.7v that the ZL1 uses. So far no issues, low pressure side on my logs holds over 70psi all the way up to E55 with no issues. Now if I could just get my high side to keep up, thats a whole nother problem.

[shinysun]

Originally Posted by TJay74

Fuel pump itself, I have a JMS box and found this out recently. I bought it up to JMS and they said they hadnt heard of any issues. With in 3 months of adding the JMS to my system my LPFP was burnt up and I had to replace it, lucky it was under warranty,

As soon as the new pump was in the car I backed the JMS back down to 16.2v and then I put the fuel pump voltage in the tune to the 15.7v that the ZL1 uses. So far no issues, low pressure side on my logs holds over 70psi all the way up to E55 with no issues. Now if I could just get my high side to keep up, thats a whole nother problem.

Oh, thank you for the info. I need to lower the voltage.

[Choda]

Originally Posted by TJay74

Fuel pump itself, I have a JMS box and found this out recently. I bought it up to JMS and they said they hadnt heard of any issues. With in 3 months of adding the JMS to my system my LPFP was burnt up and I had to replace it, lucky it was under warranty,

As soon as the new pump was in the car I backed the JMS back down to 16.2v and then I put the fuel pump voltage in the tune to the 15.7v that the ZL1 uses. So far no issues, low pressure side on my logs holds over 70psi all the way up to E55 with no issues. Now if I could just get my high side to keep up, thats a whole nother problem.

Thanks for the update. Did you work with Ted?

[G2K]

Interested in seeing Ted's comments as im sure he's been using the JMS for sometime and can provide the best feedback... I've been at 17.5 for some time now... about 7-8K miles... everything seems good but If i have to lower it would be good to know.

[TJay74]

Yes Ted knows, I bought everything from him and advised him of the issue once I knew my low side pump went out.

If the goal is to only keep the lowside at 70psi then putting the voltage in the tune to 15.7v like the ZL1 uses and the BAP to 16.2v will do that just fine.

[Dysan911]

So mine is still at the 17.5 volts. Should I dial that down to 16.2v as well? I have been running the BAP since about Mid February.

Will that drop the PSI as well on the low side? Mine is at 70.9 at WOT.

THanks!

[JANNETTYRACING]

Originally Posted by TJay74

Fuel pump itself, I have a JMS box and found this out recently. I bought it up to JMS and they said they hadnt heard of any issues. With in 3 months of adding the JMS to my system my LPFP was burnt up and I had to replace it, lucky it was under warranty,

As soon as the new pump was in the car I backed the JMS back down to 16.2v and then I put the fuel pump voltage in the tune to the 15.7v that the ZL1 uses. So far no issues, low pressure side on my logs holds over 70psi all the way up to E55 with no issues. Now if I could just get my high side to keep up, thats a whole nother problem.

Honestly the pump failure is unrelated and only coincidental.

We have installed hundreds of these over the years at 17.5 volts all the way back to 2009 on GM, Ford, and Chrysler, cars and trucks.

The voltage does not go directly to the pump it goes to the FPCM then the FPCM converts it to a PWM signal to run the pumps.

Changing the alternator voltage in the tune only further helps the whole system work better.

Lets not start a frenzy here LOL.

Ted.

[KingLT1]

Originally Posted by JANNETTYRACING

Honestly the pump failure is unrelated and only coincidental.

We have installed hundreds of these over the years at 17.5 volts all the way back to 2009 on GM cars and trucks.

The voltage does not go directly to the pump it goes to the FPCM then the FPCM converts it to a PWM signal to run the pumps.

Changing the alternator voltage in the tune only further helps the whole system work better.

Lets not start a frenzy here LOL.

Ted.

I agree... I refrained from posting until you commented because I didn't want to start a debate. BAP's get a bad wrap with a lot of shops because they are use to running them on old style fuel pumps where 17.5 volts can kill them quickly. The 6th gen pwm setup works well with the JMS like you have proven. The voltage doesn't go directly to the pump, it goes to the control module and then it converts it as needed for the pump. The idea of the JMS is to maintain consistent voltage at all times because the stock system fluctuates a lot by design and can cause variations in the voltage the the low side pump sees. As you point out changing the alternator voltage helps. I think upping the minimum to at least 12v is a good idea.

Moral of the story, adding just a JMS booster doesn't get the results, it's a combination of proper FSCM tuning along with the JMS that gets the results needed to maintain good low side pressure.

[TJay74]

Originally Posted by JANNETTYRACING

Honestly the pump failure is unrelated and only coincidental.

We have installed hundreds of these over the years at 17.5 volts all the way back to 2009 on GM cars and trucks.

The voltage does not go directly to the pump it goes to the FPCM then the FPCM converts it to a PWM signal to run the pumps.

Changing the alternator voltage in the tune only further helps the whole system work better.

Lets not start a frenzy here LOL.

Ted.

Not trying to start a frenzy and I trust you, but JMS is saying something completely different when I asked them about it after I had to replace the LPFP.

Either way it is neither here nor there, as long as the goal is to get the LPFP to 70psi and hold it there is all that matters. While it may be coincidental I just am not sure I want to take that chance again seeing as my pump went out less then 3 months after putting the JMS box on it at 17.4v.

The voltage in my FPCM tune wasnt set to anything higher than the stock Camaro SS voltage, so I matched it to the ZL1 voltage. So far every log is showing 70psi with no drops at all. So I will call it a win for now.