Mustang Injectors on an XJ 4.0L?

[alexfm]

Im sure there is mention of this somewhere else in the forum, but I didnt see it. I keep reading about using Mustang fuel injectors on an XJ 4.0L, but what are the benefits? If its something thats noticeable, I have some extra money to throw at my rig for that. IF its worth it, could some post part numbers, or at least the year/engine of mustang whose injectors i need? T

Thanks a bunch.

Alex.

 

[jeffy]

You're going to starve your engine. Stock injectors for a OBD-I 4.0L are 21.4 lbs/hr @39PSI. Ford Mustang 19lbs/hr injectors are @43.5PSI. which means they will be less at 39PSI.

Have to be a member to read this but it explains into detail what you're up against: http://4bangerjp.com/forums/index.php/topic,3479.0.html

 

[rexWRX]

I've seen the Ford injectors very cheap on eBay, both lightly used and new. If your injectors are old and tired it's cheap and easy to replace them with low mileage takeoffs from a Mustang. If your injectors are healthy I don't believe you'll see any difference. They have a 4-hole spray pattern (versus a single hole) which in theory provides better atomization of the fuel, but again, in practice I doubt you'll see much difference.

Also, IIRC, the Renix 4.0 used lower flowrate injectors.

 

[bobDog]

Im sure there is mention of this somewhere else in the forum, but I didnt see it. I keep reading about using Mustang fuel injectors on an XJ 4.0L, but what are the benefits? If its something thats noticeable, I have some extra money to throw at my rig for that. IF its worth it, could some post part numbers, or at least the year/engine of mustang whose injectors i need? T

Thanks a bunch.

Alex.

Ask joe_peters on naxja.com. he runs them and loves them. He got his on ebay used. He seems to very happy w/ them.

 

[x32792]

Hmmmm?

Would like to read more about Ford injectors in Jeep 4.0L...Always lusting from better performance and more gas milage.

Any links to case study(s)?

John

 

[ROKTAXI]

Would like to read more about Ford injectors in Jeep 4.0L...Always lusting from better performance and more gas milage.

Any links to case study(s)?

John

http://www.cherokeeforum.com/f2/more-budget-injector-upgrade-questions-13848/
I ended up putting Dodge Neon injectors on mine ('94 XJ w/ 4.0 with 120k). Butt dyno noticed a slight improvement all around. Exhaust tip looks cleaner, less sooty.

 

[gasman]

i had a 95 cherokee with over 300,000 clicks on it when i rebuilt the motor . i also swapped the intake for a 99 installed headers ,high flow cat ,and a super 44 off road magnaflo exhaust, i then swapped out the injectors for these ones

http://www.precisionautoinjectors.c...435FCA8AC9B26F33EC3.qscstrfrnt04?categoryId=3

i think they worked pretty good, let me edit here, with the whole rebuild and the 4.88s on 35' the jeep hauled ***. i cant tell you for sure if the injectors made a difference cuz i rebuilt everything, the injectors i got were flow matched had 4 hole spray pattern, and lifetime garauntee, and for the price there is no question , got all 6 for less than the price of 2 new ones

 

[lthixson]

Neon injectors

I installed the Neon injectors in my 98 XJ and noticed easier starts and smoother idle, but mpg and power remained about the same.

 

[sjk99]

most of the injector swapping occurs in the context of building a stroker. The theory is the stock injectors won't flow enough. But it depends on what set of stock injectors you start with.

In addition to the cherokeeforum.com link search on naxja.org
(http://www.google.com/search?source...e+Search&aq=&oq=ford+injectors+site:naxja.org)

and
http://www.jeepstrokers.com/forum

Plenty of good reading on all three of those sites.

 

[madizell]

There is nothing magical about "mustang" injectors. They are a simple, typical automotive Bosch-style injector. The real question is whether the ones you have are working as they should. If they are, and if they don't deliver enough fuel, you must have made some serious modifications to your engine, in which case you may need to decide how much injector your need. Whatever you decide, don't change them just to have something that came out of a muscle car. Get the ones you need for the job.

 

[madizell]

Or, let me put it another way. My Jeep has a 5.0 Mustang V8. It came with 19 pound hour injectors running on 39 psi fuel pressure, vacuum regulated but not adjustable per se. Having changed everything on the motor except the crank and cam, I find I need a bit more fuel to provide the HP I can otherwise get from the heads, intake, and exhaust I have. Rather than change out the injectors, I ran the anticipated HP specs through a website for injectors and found that I need around 23 lb/hr. I can get that out of a 19 by abandoning the 80 percent duty cycle, and raising the fuel pressure at the rail. So, I installed an adjustable pressure regulator that will allow me to raise the pressure infinitely to the limit of the pump, which will put out something around 90 psi. By using the formula provided on the web, I determined that I can get what I need with 55 psi but I am running between 90 and 100 percent duty cycle. And it works. It also tends to overwork the injector, which will shorten its service life, but then, if I need to replace them, I will get 24's and call it good.

 

[bldeagle10]

i had a 95 cherokee with over 300,000 clicks on it when i rebuilt the motor . i also swapped the intake for a 99 installed headers ,high flow cat ,and a super 44 off road magnaflo exhaust, i then swapped out the injectors for these ones

http://www.precisionautoinjectors.c...435FCA8AC9B26F33EC3.qscstrfrnt04?categoryId=3

i think they worked pretty good, let me edit here, with the whole rebuild and the 4.88s on 35' the jeep hauled ***. i cant tell you for sure if the injectors made a difference cuz i rebuilt everything, the injectors i got were flow matched had 4 hole spray pattern, and lifetime garauntee, and for the price there is no question , got all 6 for less than the price of 2 new ones

go with these over mustang injectors! these would be the better option in my opinion and im getting ready to fork over the cash for a set really soon

313k on my 99 xj. think its ready for a little freshening up

 

[wADVr]

The 5.0 injectors are only a mod for the 87-90 renix 4.0 5.0 injectors in a '91+ 4.0 would be a decrease in flow.

10 years ago this was a great sub $100 mod for these engines with leaky injectors and/or hard starting issues. Im sure there are better options out there now, doubt for less money though.

 

[wikun]

The 5.0 injectors are only a mod for the 87-90 renix 4.0 5.0 injectors in a '91+ 4.0 would be a decrease in flow.

10 years ago this was a great sub $100 mod for these engines with leaky injectors and/or hard starting issues. Im sure there are better options out there now, doubt for less money though.

x2 The 19# mustang injectors flow the exact same as the Renix injectors with the exception of how they do it. The Renix injectors have one "nozzle hole" where as the mustang's have 4. Also it has been said that they atomize the fuel better, resulting in a better burn and a possible increase in gas mileage. I have yet to throw them on, though. Do not swap them into a non-renix engine though because you will be starving the engine which = bad things. 91 and up = no bueno:costumed-smiley-007