mosiv053

My question is about throttle body to injector ratios I have an '01 XJ 4.0 HO I6 that is my daily driver but is also my build vehicle with Rough Country 4.5" lift, K&N intake and some other upgrades but i recently installed the BBK 62mm throttle body and love the throttle response it gives me but i've been really curious; Did i do more harm than good? I've heard that bored out throttle bodies are great for throttle response and a tiny bit of HP but i would really like to know, to gain the most benefit from this "should" i upgrade my injectors to keep the air/fuel ratio optimal? If so what should i upgrade my injectors with, i've heard about 18lb injectors but i would really like to see some numbers if anyone has worked out the formulas to get the most from this awesome bolt on upgrade Also: Yes it whistles. TB + Intake= pretty cool sounds IMO. Thanks All!

JEEPFREEK

Can someone shed some light on this topic i have the same situation myself i have installed the BBK 62mm TB bought the high flow headers and the high flow magnaflow exhaust and was wondering what size injectors would be good for this set up, i was thinking on one size up from stock but not too sure

let's see what kind of knowledge this site has on the 4.0L

rainman

Bosch 784 injector for the 01
Bosch 703 for the '98
For thease threads your engins would be regarded as stock.
http://www.ausjeepoffroad.com/forum/...ad.php?t=92236

https://www.cherokeeforum.com/f2/mor...-13848/index2/

no rdplz

^^Correct. The 784's can easily be found in 98-01 Neon's/Stratus's/Caravan's with the 2.4 engine. 703's can be found in the same Chrysler/Dodge vehicles with the 2.0. If you can't/don't want to go to the JY and do the work yourself, there's a few guys on here that sell the "upgrade injectors" for $60 a set.

TrekkerJmm

I had my TB bored to 64mm by http://www.strokedjeep.com/tbody.html and have no whistle at all and changed my injectors to 703's and gained HP and MPGs...Tj

x91j

do i need 703s for my 97?

no rdplz

You can run either 703's from Chrysler 2.0 engines, or the Ford "yellow stick" 700/710's. I have a set of the yellow sticks if you're interested.

x91j

how much?

no rdplz

$60 shipped. That's for them to be ready to install. If you want them untested and without new o-rings it's $45.

happyjeeper

What injectors for a 2000 XJ? I want to do the upgrade but not sure of the value of doing hte process?

cruiser54

The PCM or ECU will compensate for the increased air volume. No need to change the injectors to a larger size. There's plenty of "headroom" in the stock injectors unless you're building a stroker or using forced induction.

1FSTREX

784s.

Benefits: Better gas mileage, better starts, better idle.

We basically have one hole that sprays fuel, these have four holes that spray fuel. You get a cleaner more refined spray that can be processed smoother and faster. Or something to that sort.

skindiver808

Hi I have a 94 xj wht injectors would I want to get?

XJnLvilleGA

703s and I have a set for sale, with brand new felpro rings.. Yours for 50 shipped.. Lmk..

bronzo1217

I have a 95 what injectors for me?