Injector Swap Writeup for the 4.0L

[Truckedup]

The new injectors are installed,this is a 99 5 speed 4.0. I got them on Ebay from large injector rebuilder, two year guarantee.They are Bosch for Dakota V-8. The snap clips retaining original injectors to the fuel rail couldn't be used because there's no groove in the new injectors. With the fuel rail bolted down the injectors are captive and can be only forced up or down maybe a 1/32 inch.
On the road; I have several XJ 5 speeds and they all feel a bit flat from 1500-2500 rpm in the top three gears. With the 4 hole injectors the part throttle response is noticeably sharper in that speed range. Full throttle power is about the same,the idle maybe a bit smoother.
Was it worth 100 bucks and a few hours time? I guess so.....

 

[BlurpleXJ]

For whats its worth, tried a set of 703's in my '98 and wasn't pleased. Mileage went down, power didn't change much and it seemed to run pretty rich. Used the best 6 injectors of 8 that I pulled, after I cleaned them with the same method posted in the video earlier.

By comparison, the 0280156007 injectors I pulled from a Dodge minivan made a definite difference in the 1500-2100 rpm range. And, I gained about 0.5 mpg. I'll take what I can get. For the $60 I paid for them it isn't too bad. Did have to buy $12 worth of adaptor plugs though.

 

[dukie564]

there's no reason why they wouldn't perform as good or better than stock injectors if they are all clean and working correctly. Did you reset the PCM? It takes up to 50 startup cycles to set the A/F ratio in the computer after the reset.

 

[BlurpleXJ]

Yep, sure did. Maybe it would have leveled out over time and adjusted properly, I gave it about two weeks as my DD before I pulled them and put the stockers back. I seem to recall others reporting issues with 703's on the 49psi fuel rail, so I figured that was my issue and located the 007s. The 007s showed an immediate improvement, and seem to only be getting better over the past week. YMMV. I'll make a longer-term report on things once I've run them a month or so.

 

[Cburb88XJ]

Is there any info on maybe cross reference of Bosch 0-280-155-703 the EV1s id like to look into buying new maybe but if you look on parts stores under all the vehicles that are supposed to have the right injectors the numbers are way off, like on rockauto i cant find 703s anywhere listed. I bought a different set of injectors a while back but the ones i got are orange i believe and they have that wide metal part. Unlike some that are all black and look plastic like the guy who started thread is using.

 

[dukie564]

http://www.fuelinjector.citymaker.com/catalog/item/4511825/4735791.htm

Bosch 0280155703
OEM 5227386
Chrysler, Dodge, Plymouth casting 5277739
Borg 67167
Standard FJ213
Bostech MP1015

 

[Dragonslayer]

Dukie564 - Good writeup on swapping the injectors. I did this swap myself a while ago.

I would like to add a step to the procedure. Step 10.5: Squirt a bit of silicone lube
at the base of each injector (where they seat into the intake manifold). Then grasp
the fuel rail with both hands and gently rock it up and down a bit in order to help the
silicone lube to penetrate and soften those dry, hardened, injector O-rings.

This will make it much easier to pull the rail away from the manifold, in Step 11.

 

[Tony_SS]

for a 2000, what would be the difference in the 784 injectors and these Ford injectors?

http://www.ebay.com/itm/271370065390

 

[dukie564]

less flow. Although some have used with success, i don't see it as an upgrade if you're decreasing the available flow...

Ford 19# XF2E-C4B: 204cc @ 43.5PSI
Stock Injectors: 230cc @ 43.5PSI

 

[Tony_SS]

Thanks, I'll stick with the 784's.

 

[Talyn]

Check out the Bosch 0-280-156-007/ Jeep 04861454AA. They flow 22.2 lb/hrs, which make them a very good fit for the stock 4854181 injectors. Much better than the oversized Neon injectors. Credit goes to Solarbell for the injector recommendation.

 

[bludevil]

it's easy if you make it so.

best option is *703 injectors for pre-2000 XJs, and *784 injectors for 2000-2001 XJs (different electrical connector).

Found in mid-90s chrysler/dodge cars/vans (late 90s for *784s)

I have a 98 xj and I have found to diff 703s on ebay. tHE BUICK/CADILLAC AND THE CHRYSLER/DODGE 703s so my question is there any diff on the two or do I just stay with the Dodge/Chrysler
:banghead:

 

[dukie564]

Chrysler/dodge

 

[Truckedup]

And I also installed the yellow Ford injectors in my 97 4.0 5 speed. About the same as my 99 swap report but with more top end and the idle remained the same as before the swap. Fuel mileage is maybe slightly better.

 

[floyd]

Okay, so I picked up a set of bosch style injectors and am installing them tonite. However, when I pulled out the stock injector(s) and compared to the new, the new ones have a plastic "cap" on the business end and the stock injector does not. Should this be removed? My concern is it melting and ending up in the cylinder.

Pic:

Help!

 

[floyd]

May have answered my own question, it appears the OP left them on. I will go with it!

 

[cruiser54]

Leave it on. It sticks into the manifold, not the cylinder...

 

[Talyn]

Normal, leave it.

 

[floyd]

Well, the process was easy, the finish product, not too good. All done, fired up the Jeep, and gas started spraying out the number 3 injector where it sits in the manifold (as best I can tell). Disassembled, checked all injectors were seated in the rail, reinstalled into the manifold, same problem. I do note that number 1 and 2 injector don't seem to 'rotate' in the manifold easily and number 3 seems more loose for lack of a better term. Could the O ring be too small? They certainly all looked to be the same when I received and inspected the injectors.

 

[cruiser54]

Might have twisted an o-ring. Did you install the o-rings or someone else?