'97 Jeep 4.0 Fuel Injectors

XtrmTJ · Nov 23, 2009

Can anyone walk me threw a fuel injector (6) remove/install ? Special tools needed? Do's and Don'ts ? Tips to make it easy as falling off a cliff. TIA ! :awesomework:

XtrmTJ · Nov 24, 2009

What, NO one has ever done this ? I am sure I can do it blindfolded, but alittle insite would help, ... alot . :fawkdancesmiley:

sideshow1 · Nov 24, 2009

Injector install

I'm new here but I did this on my 97XJ a few months ago. E-bay has factory service manuals on CD; seriously, it's well worth the 30 bucks or so.

Go buy new injector o-rings (this is important). Disconnect the battery. Remove the schrader valve cap and bleed the fuel pressure from the fuel rail, a screwdriver and rag will do the job. Label, then remove the injector plugs (whiteout pen works great). Remove the clips that retain the injectors on the fuel rail (they only go one way and a screwdriver works). I believe 4 bolts secure the fuel rail, remove them. Yank and wiggle up on the fuel rail, evenly if possible, the injectors may or may not come out with the rail. Some of them will be remain in the intake a little wiggling and pulling will be necessary to completely remove the injectors.

Upon installation, the manual says to coat the o-rings in motor oil, I have used fuel lube or vaseline with similar effects.

zukkev · Nov 24, 2009

What's the matter with the ones on the rig??? Use plenty of lube (vasiline works good:redneck

on the orings....don't just push them straight into the rail, or you stand a good chance of cutting 'em.... twist them in carefully, watching that the oring doesn't try and push out of the rail...:awesomework:

zukkev · Nov 24, 2009

sideshow said:
I'm new here but I did this on my 97XJ a few months ago. E-bay has factory service manuals on CD; seriously, it's well worth the 30 bucks or so.

Go buy new injector o-rings (this is important). Disconnect the battery. Remove the schrader valve cap and bleed the fuel pressure from the fuel rail, a screwdriver and rag will do the job. Label, then remove the injector plugs (whiteout pen works great). Remove the clips that retain the injectors on the fuel rail (they only go one way and a screwdriver works). I believe 4 bolts secure the fuel rail, remove them. Yank and wiggle up on the fuel rail, evenly if possible, the injectors may or may not come out with the rail. Some of them will be remain in the intake a little wiggling and pulling will be necessary to completely remove the injectors.

Upon installation, the manual says to coat the o-rings in motor oil, I have used fuel lube or vaseline with similar effects.

If the clips are there holding the injector to the rail, they should come with the rail.:awesomework:

zukkev · Nov 24, 2009

If you're replacing them, go with a set of Bosch's from a 4.0 explorer...much better injector, and a little more flow rating (noticed a bit more power (at least compared to the ones that were in my 89 XJ...)...

sideshow1 · Nov 24, 2009

zukkev said:
If the clips are there holding the injector to the rail, they should come with the rail.:awesomework:

Yeah............ok

, Not to be nitpicking:fawkdancesmiley:, in hindsight they're probably easier to pull from the intake rather than the fuel rail.

zukkev · Nov 24, 2009

sideshow said:
Yeah............ok , Not to be nitpicking:fawkdancesmiley:, in hindsight they're probably easier to pull from the intake rather than the fuel rail.

Yup, just pull the rail and injectors as an assembly and set the rail on a bench...just did my XJ last month...done in less than an hour.

Avanteone · Nov 24, 2009

zukkev said:
If you're replacing them, go with a set of Bosch's from a 4.0 explorer...much better injector, and a little more flow rating (noticed a bit more power (at least compared to the ones that were in my 89 XJ...)...

FWIW, you put 19lb/hr injectors in place of the stock 18.6lb/hr injectors in your '89 XJ, which is fine and is a common upgrade. Anything '91+ in a 4.0 is a H.O. motor and uses 21lb/hr injectors.

J

zukkev · Nov 24, 2009

Avanteone said:
FWIW, you put 19lb/hr injectors in place of the stock 18.6lb/hr injectors in your '89 XJ, which is fine and is a common upgrade. Anything '91+ in a 4.0 is a H.O. motor and uses 21lb/hr injectors.

J

What he said!!!:redneck::haha: For some reason I thought the post said '87 !!!:haha: Thanks for making me see the light John, and clearing that up!!!!:awesomework:

XtrmTJ · Nov 25, 2009

TY ! I was getting an error code says an injector was misfireing ? Got a set from Precision Auto Injectors, they say better starts, smoother idle, better throtle resonce and more mpg's. ALL that for 129.99 to my door ! :cheer: I'll put them in this weekend and let ya all know how it turned out. :hi:

zukkev · Nov 25, 2009

XtrmTJ said:
TY ! I was getting an error code says an injector was misfireing ? Got a set from Precision Auto Injectors, they say better starts, smoother idle, better throtle resonce and more mpg's. ALL that for 129.99 to my door ! :cheer: I'll put them in this weekend and let ya all know how it turned out. :hi:

Did you have a misfire code??? such as a P0301???

XtrmTJ · Nov 25, 2009

Error Code # 43 Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders 1 thru 6.

Along with 12 and 55. 12 is battery disconected from PCM in last 50 starts and 55 is end of error code check.

Hope is that new/remanned injectors will end this error code.

zukkev · Nov 25, 2009

XtrmTJ said:
Error Code # 43 Peak primary circuit current not achieved with maximum dwell time. Misfire detected in one or more cylinders 1 thru 6.

Along with 12 and 55. 12 is battery disconected from PCM in last 50 starts and 55 is end of error code check.

Hope is that new/remanned injectors will end this error code.

This is a 97, right??? Misfire code? Should be OBDII codes (P0..., or something along that line)---What the heck piece of equipment are you using to check codes with??? I just googled code 43 (I found exactly where you found your description of the code....:

, and on pre OBDII rigs, it pertains to the battery temp sensor/circuit....On OBDII rigs, it does pertain to multiple cylinder misfires, specifically the ignition system, but says nothing about injectors...Better check out your ignition system (plugs, cap, rotor, wireset, etc...These are known for causing misfire codes!!!:awesomework

---I certainly wouldn't run out and buy a set of injectors because of this code, unless I knew FOR sure I have exhausted all avenues of why this code could set. Of course, I have the equipment to diagnose whether its the ignition, or injectors...:;

XtrmTJ · Nov 26, 2009

I did exactly that, all new, cap, rotor, plugs, wires, even a new distrib. new crank posision sensor, new fuel pump, fuel injectors are next ? Yes it is a 97, I use the jeep its self to read error codes, turn on/off 3 times and it shows error codes in the odometer, plus the "ckeck engine" light flashes the number of times to indicate the error code.

XtrmTJ · Nov 26, 2009

Batt temp sensor is error code #44.

JOOP · Nov 26, 2009

Wanna buy a Innova OB I&II scanner?? $125.

XtrmTJ · Nov 26, 2009

And how many years of "schooling" do I need to read that gismo ?

zukkev · Nov 26, 2009

If you did all that, what brand stuff did you use??? Did you replace the ignition coil??? Is it misfiring??? Or is it just the check engine light is on??? And yes, I forgot Chrysler still allows you to read codes the old skool way even on OBDII stuff, at least up until recently.:awesomework: Cade 43 on OBDI is the battery temp sensor, it may be 44 on OBDII...