Fuel Injectors?

Angel Rivera

New Member

Jul 8, 2014

19

0

1

Rochester NY

Sep 21, 2014

#1

• Sep 21, 2014

• #1

Hey everyone!
I recently done a full PI swap and car has been running a bit lean. It still using stock injectors so I have been thinking about swapping for some new fuel injectors. Both LateModel and American Muscle have 19lb and 24 lb ev1 injectors, but which option would be better suited? The rest of the fuel system is stock as well.

 

Three50won

10 Year Member

Jul 11, 2010

1,135

64

69

Sep 22, 2014

#2

• Sep 22, 2014

• #2

You should be fine with the 19 pounders. I have a full bolt-on 03 GT and the 19 pounders are more than enough for my engine.

 

Angel Rivera

New Member

Jul 8, 2014

19

0

1

Rochester NY

Sep 22, 2014

#3

• Sep 22, 2014

• #3

Okay, did you go with the Accels? Also, did you need a tune or was it a direct swap with no issues?

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Sep 22, 2014

#4

• Sep 22, 2014

• #4

How are you measuring the AF ratio?

Consider that there are several "other" possible causes for a lean condition:

• Exhaust leak
• low fuel pressure
• intake vacuum leak
• Clogged fuel injectors. Consider an injector cleaning service such as injectorRX.com

 

Angel Rivera

New Member

Jul 8, 2014

19

0

1

Rochester NY

Sep 22, 2014

#5

• Sep 22, 2014

• #5

I data logged the a/f ratio percentage. I checked the pressure in the rails which is fine, and check all vacuum leaks and actually improved the ratio (mechanic forgot to put on the air filter). Clogged injectors maybe be possible since they are original, and I am not sure which fuel was used prior to my ownership. I currently run 91 no eth. and I think the 3 hole spray would be more effective than the stock one hole injector design. I could possibly clean them but it might be time for an update anyways.

 

TeamCaffeineGT

Member

Mar 16, 2009

193

15

18

Springfield, MO

Sep 22, 2014

#6

• Sep 22, 2014

• #6

The PI swap raises the compression ratio by increasing the cylinder volume resulting in greater air flow. This went from 9.30:1 in the non-PI engines to 9.74:1 in the PI engines. The increased airflow could be causing the lean condition, but your MAF should be picking up the increased airflow and the ECM would adjust accordingly.

What is your A/F Ratio right now?

Garrett's website puts it best: " A lower AFR number contains less air than the 14.7:1 stoichiometric AFR, therefore it is a richer mixture. Conversely, a higher AFR number contains more air and therefore it is a leaner mixture."

 

Sharad

ALWAYS choose the V over the P!!! Wait... what?

Jan 5, 2011

1,562

480

94

Fort Myers, Florida

Sep 22, 2014

#7

• Sep 22, 2014

• #7

Correcting the AFR through the tune, rather than installing bigger injectors without calibrating the MAF, will give you better driveability and fuel economy.