01 Jeep GC new injectors=significant MPG increase

[Donald]

I had new injectors put in my Jeep and went from 19 to 26 MPG. I believe the injectors were original and had 155K miles. The engine is a reman and has much less but they would have used the old manifolds, etc. The new injectors are 4 port injectors that are a direct fit for the OEM single port ones (new ones supplied by Trav (Paul)). I was expecting 10 - 15 % improvement but this is about 25%. But as they say YMMV.

 

[splinter]

My hypothesis is that they’re injecting significantly less fuel.

 

[Nick1994]

Whoa, that sounds almost impossible. What brand/ model are they? My grandpa and brother have Cherokees with the 4.0L

 

[Donald]

Things may even get a little better as the ECM figures out the new injectors.

 

[3800Series]

Any lose of power/ acceleration?

 

[Donald]

Originally Posted By: Nick1994

Whoa, that sounds almost impossible. What brand/ model are they? My grandpa and brother have Cherokees with the 4.0L

Contact Trav.

 

[Donald]

Originally Posted By: 3800Series

Any lose of power/ acceleration?

Runs slightly smoother, everything else the same. The Jeep 4.0 was never a "race you off the line" kind of vehicle.

 

[GumbyJarvis]

Now drop a K&N Cold Air intake in and boost your MPGS even more!

 

[gathermewool]

How has your afr been affected? Fuel trim?

 

[wsar10]

Originally Posted By: Donald

I had new injectors put in my Jeep and went from 19 to 26 MPG. I believe the injectors were original and had 155K miles. The engine is a reman and has much less but they would have used the old manifolds, etc. The new injectors are 4 port injectors that are a direct fit for the OEM single port ones (new ones supplied by Trav (Paul)). I was expecting 10 - 15 % improvement but this is about 25%. But as they say YMMV.

That's a very common outcome with the injector upgrade. Did you use "neon" injectors ? I have alway had noticeably smoother idle aswell.

 

[dishdude]

I didn't think anyone ever got 26 MPG from a 4.0, especially a GC. My mother had a 2000 and I don't think it ever broke 20. Great vehicle otherwise.

 

[demarpaint]

Trav hooked me up as well and the increase in mpg in my van was a tremendous improvement. The 27 year old injectors were tired.

 

[jk_636]

I can buy this. If you had some really gummed up and blocked injectors, your vehicle is now operating at optimal efficiency and you are finally getting a good fuel/air ratio. Now stop using cheap gas and start using MMO in the tank to keep those injectors from getting blocked in the first place!

 

[SwampSurvivor]

I have been wanting to do this to mine for a while now!

Originally Posted By: jk_636

I can buy this. If you had some really gummed up and blocked injectors, your vehicle is now operating at optimal efficiency and you are finally getting a good fuel/air ratio. Now stop using cheap gas and start using MMO in the tank to keep those injectors from getting blocked in the first place!

The spray pattern on the stock injectors are horrible.

 

[xxch4osxx]

I wonder if new injectors would make a difference in my Silverado.

 

[Warstud]

Originally Posted By: Donald

I had new injectors put in my Jeep and went from 19 to 26 MPG.

How are you calculating MPG's. The old fashioned way or electronically?

 

[Trav]

Originally Posted By: xxch4osxx

I wonder if new injectors would make a difference in my Silverado.

These GM use a decent Bosch injector with a spray good pattern. Cleaning these can bring them back to 100% no need to replace (unless one is defective) or upgrade.

 

[Donald]

Originally Posted By: Warstud

Originally Posted By: Donald

I had new injectors put in my Jeep and went from 19 to 26 MPG.

How are you calculating MPG's. The old fashioned way or electronically?

The vehicle has an overhead trip computer that gives avg MPG and a few other items.

 

[Donald]

Originally Posted By: jk_636

I can buy this. If you had some really gummed up and blocked injectors, your vehicle is now operating at optimal efficiency and you are finally getting a good fuel/air ratio. Now stop using cheap gas and start using MMO in the tank to keep those injectors from getting blocked in the first place!

I will stick with the 26 MPG and leave the MMO on the Walmart shelf for others to purchase.

 

[Papa Bear]

Originally Posted By: Trav

Originally Posted By: xxch4osxx

I wonder if new injectors would make a difference in my Silverado.

These GM use a decent Bosch injector with a spray good pattern. Cleaning these can bring them back to 100% no need to replace (unless one is defective) or upgrade.

Trav, how about a 2007 Chev Uplander 3.9?