Performance plus

I have a 97 xj and i want to go with four hole injectors...but which ones are best...someone mentioned neon injectors but which ones...and what changes would i have to make to get them to fit or are they plug n play. I also am adding a 99 xj intake with a 62mm throttle body...what should i expect...thx

Cummins93

I have a bias opinion as I sell all of the things mentioned. My XJ kit is a set of refurbished bosch 923 injectors (4 hole). Conversion plugs for ev1 to ev6. A 62mm bored throttle body and an advanced CPS.

All together you can expect an increase in throttle response and less throttle angle during highway cruising. Depending on your current fuel injector condition you could see better idle as well.

Performance plus

That sounds great..how much are your kits

EvanM

Honestly youl probably be disappointed in the lack f increased performance after the intake and injector swap.
injectors have alot of miles I'd stick 4 or 12 hole in there and call it good. You might notice a smoother idle. The but dyno wnt pick up much horsepower increase

RockyMtn96XJ

Yeah these aren't race cars. It takes a lot of work and money to get enough power to be noticeable. After all, these are pretty much tractor motors, hence the concept of using diesel oil in them. So if you want a lot of power, put a V8 in there, or even a turbo, but that'll take a lot of work and upgrades as well. Not to take away from someones business though.....
But if you need the throttle response and want a hair better MPG (if you can keep your foot out of the pedal), the injectors are a good option. Don't mix up better throttle response with more power. it may be there, but its negligible. The better flow of fuel and better mist pattern is helping with the throttle response. The throttle body will help too, but don't expect to squeal the tires from the red light.

Performance plus

No...i don't want to make it a hot rod...( i know she's a tractor..even if she doesn't think so...lol ) but she has 240.000 miles on her and i just want better throttle response. Maybe I'll just do the injectors...62 mm throttle body...cold air intake..and exhaust. I'm hoping if she can breathe a little better it will not be so hard on the motor...thx

RockyMtn96XJ

Yeah sounds like a plan. I wish I had the extra time to tinker around and do that stuff. I may get lucky one day and be able to throw some injectors in.

EvanM

Gears

XJlimitedx99

UH OH. Que Cruiser to come tell you the 4.0 was never used as a tractor motor in 3... 2... 1.....

I've accumulated most of the bolt on's one could add over the years, short of headers (cowl intake, 62 mm throttle body, 4 hole injectors, MSD ignition, 2.5" header back exhaust) and although she runs healthy, I'm not convinced its done much. Pretty much just threw money at it cause I was bored and it was burning a hole in my pocket. Hard to have an objective opinion when its pushing 35's with 3.55 gears. I swear I'm gonna regear it someday!

BlueRidgeMark

That's all reasonable. Now if your expectations are reasonable, you'll be happy with the expenditure. I've done the injector upgrade, and I would never consider doing it JUST for the HP increase, but if you are replacing them because they are bad, I think you are crazy NOT to go with 4 or 12 hole.

Cummins93

I would group 4.0L n/a into a few performance categories

1) 62mm TB, 4/12 hole injectors, ADV timing CPS

2) higher ratio roller rockers, head porting, headers.

3) bigger valves, higher compression, stroker

I grouped these together in these stages because of time and money put in to power out comes. Each successive stage is complemented by the previous stage. Higher octane fuel would be required starting with stage 1 and would require premium by stage 3. A cold air intake has been excluded from the list as it is usually a hot air intake and not effective. Gearing has been excluded as the question is just about more power out of the engine but should be considered if larger tires have been equipped.

Performance plus

I know there's very little difference in a cold air intake ( seeing how it's still under the hood ) and stock airbox but what about cowl intake...is it any better...are any CAI worth the money over the stock set-up...or are they more fashion then function..

Tsaani97xj

^^^^THIS^^^^

Nothing short of a stroker or engine swap will make as drastic of a difference.

Go find a pair of rims and tires that are smaller than what you have. The smaller the better. Then go take a ride and you can feel what a gear change would do. **just a cheap way to experiment**

cruiser54

https://en.wikipedia.org/wiki/AMC_straight-6_engine

Red1992XJ

I heard these words in Samuel L Jackson's voice, and I laughed pretty hard.