Injector upgrade thoughts.

[Turismo07]

Originally Posted by Billnick

Makes me wonder how you installed them. I initially had problems when I installed the injectors in the manifold first, then tried to fit the fuel rail. On some the O ring would go in but the plastic bit would not. After a lot of messing around I found the sequence to be to slop dishwashing liquid on the top O ring then fit the injector first to the rail + the clipnut, then with all the injectors fitted slop dishwashing liquid on the bottom O rings and slide them all in to the manifold. I'm wondering if you are losing pressure when the engine is off i.e. petrol is leaking out and evaporating and takes a second or two to repressurize.

I don't 'think' this is my prob. My injectors clearly fit into the rail (after the mod) and the maifold exactly as the stock ones did i.e. they go in the same depth. They are also very tight (I did lube the o rings when installing as you should), in fact getting the rail with the injectors installed back into the manifold was the hardest and most time consuming part of the whole job! Also there is no fuel smell in the engine bay which would suggest fuel leaking...

Interestingly when the Jeep is fired up first thing in the day (ie. cold engine and been left overnight or for a few days) it always starts imeediately, i mean you literally barely hear the engin crank and it just leaps into life. But then after its warm thats when it'll intermittently take up to 5secs of cranking before firing up...

Originally Posted by sturz_00

turismo have same problems as you, i to have the V6 injectors in mine and after speaking to an injector specialist he mentioned they will work but to work properly you need to fit injectors made for the XJ apparently all to do with the amount of ohms, the cam angle etc etc out of my league anyway so having originals tested and refurbished to see how they go??

Interesting info there, bit beyond me as well. Be interested to hear your results after refitting the stock injectors. Still od that no one else seems to be having these issues...

[rainman]

IF the prolonged crank is very constant when hot, try spraying the coil and the crank sensor with water leave it 5 minutes and see if it starts right up . I would think this is possible rather than probable, however spraying with water and waiting 5 mins is cheap and it can rule something out.

[dazza96]

off topic i know but i had this hard to warm start when my dizzy was flogged out fix was a new dizzy

[rharr]

I know you say these are for 99 and up xj's can these be made to work with 95 xj's if you use a hesco adjustable fuel regulator and swap out the EV1 plugs for the EV6 plugs? or does the whole variable pressure deal throw a monkey wrench in every thing?

Originally Posted by rainman

Injector upgrades.

Another alternative for the stock 99-up 4.0L is the (22.8#=240cc @ 43.5psi) Ford XR3Z 9F593 A4B / XR3E 9F593 A4B which is the newest design and offer even better performance.


(MOTORCRAFT #CM-4956,CM4956 XR3Z9F593AB, XR3Z-9F593-AB, XR3E9F593A4B, XR3E-9F593-A4B, YR3Z9F593AB, YR3Z-9F593-AB=all the same injector)
This injector has a single hole and looks disappointingly similar to the stock 99-'01 injector .
The main method for increasing atomization in the ev6 injectors was by increasing holes number and reducing each hole size. One can't add holes and reduce size indefinitely, so a new approach was needed when regulations became more strict.

The newer design is not relying on number of holes, it's a completely different approach with the difference in the internal orifice which allows far better atomization. This also gives an even better ability to work on variable pressure, as with most newer cars the pressure is computer controlled.
This, in turn, gives more accurate fuel mixture at any given pressure.


You can check the two in your fuel rail, when out, and compare the spray pattern, with the newer the fuel is like a mist.
Currently these can be bought near new for around $60 a set on ebay.
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[rainman]

Originally Posted by rharr

I know you say these are for 99 and up xj's can these be made to work with 95 xj's if you use a hesco adjustable fuel regulator and swap out the EV1 plugs for the EV6 plugs? or does the whole variable pressure deal throw a monkey wrench in every thing?

**************EDIT*********************
the difference in flow between that injector and the neon 703 injectors @ 39psi (stock pressure @ WOT in a OBD1 '95) is very little/ trivial, only thing is while those injectors are supposed to have a wide operating pressure I can not vouch for how they work in the 31-39 PSI range - SHOULD- be ok but do not know for sure.
the adjustable hesco would be a nice touch although I would be tempted to try with out it, just go easy on the first few runs and use a oxy sensor read out to see if it is leaning out.
if it does just drive easy till the hesco FPR shows up in the post a week after you bought it.
should work, never tried it so can not guarantee anything.

why not just use the neon 703's? less than $200 at the door no more to pay -plug and play.
good luck with it

[rainman]

edit on the previous post.

[rusty577]

guys im looking to improve my fuel economy and a shake/vibs at idle after installing brown dog engine mounts.

currently running 3' lift 31" muddies and tjm roof racks box. getting between 16 to 18l per 100km mix the motorway and around town, thats keeping revs under 3k and drivin like a granny. More then normal. id like to get it down to 14/15l

ive got a crack in my headers at the collector and im thinking what kinfa of fuel improvment with commodore injectors amd new extractors.

its a 96 obdII.