Fuel pump need a tune??

**legacy95** · #1: 05-08-2012, 07:37 AM

I just purchased a Deatsch dw65c fuel pump for my 05lgt. Will I need a tune when this is installed or will the fuel pressure regulator do its job.

**austin42008** · #2: 05-08-2012, 08:25 AM

You don't need a tune for the fuel pump

**fahr_side** · #3: 05-08-2012, 08:47 AM

Depends. If you had IDCs pushed into the 90s on the stock pump, with the stock MAF scaling you might not hit rich AFR targets. Since the stock MAF scaling isn't too awful many tuners will not change it, but just target a slightly higher AFR than is wanted.
For example you might target 10.5 AFR knowing very well the stock fuel system can only hit 10.8, which is what you wanted all along. Now you upgrade the pump and suddenly you can reach 10.5 AFR or even richer. You have more safety in that your pump isn't getting its neck wrung, but you will probably lose a bit of power.
While I might not re-tune the car for this I'd probably want to check AFRs at high revs to see they are what you wanted and tweak to suit.

**mcg_** · #4: 05-08-2012, 11:54 AM

fahr_side, so are you saying that a new fuel pump won't harm a stock LGT (i.e., not tuned)?

**fahr_side** · #5: 05-09-2012, 09:56 PM

If you're stock it probably won't make any difference. If it does it might be richer by 0.1 AFR up top.
The guys who are running 90%+ IDC and stock MAF scaling will have more issues with this.