Aftermarket Fuel Injectors

[JaVeLiN]

OMG... 425,000 miles !!! The 4.0 is stout?

 

[bulfo4]

For anyone thinking about using this Precision Auto Injectors company, here's what happened to us:

http://www.jeepforum.com/forum/showthread.php?p=14810729#post14810729

In hindsight, cleaning them ourselves doesn't look like it's too bad based on some youtube videos, especially if they're pretty new or just not completely trashed.

Haven't compared many different kinds of injectors (probably should have, but the guys on the Stroker Forum seemed pretty keen on the 24lb Ford injectors), but when ours worked, they were definitely better than the stock ones, smoother and more power, didn't leak, and no idea on gas mileage from our brief time with them.

 

[jx2991]

I picked up a set of 703s from the JY. I'm plan to clean them and put them in this week end but I'm having trouble finding the little plastic hat shaped caps at a parts store. The stock Jeep injectors have a ridge cast into them instead of using the plastic set up. Does anybody know what they're called and maybe where to get them? Do I even need them?

 

[Ben824]

I picked up a set of 703s from the JY. I'm plan to clean them and put them in this week end but I'm having trouble finding the little plastic hat shaped caps at a parts store. The stock Jeep injectors have a ridge cast into them instead of using the plastic set up. Does anybody know what they're called and maybe where to get them? Do I even need them?

They are called Pintle Caps and Napa carries them. Make sure to take atleast one good one with you so you can match it up with the right ones.

 

[jx2991]

They are called Pintle Caps and Napa carries them. Make sure to take atleast one good one with you so you can match it up with the right ones.

Thanks. Having a name for them will make it a lot easier to find them. Good call on taking one with me. Looks like I'll be going shopping tomorrow. :thumbup:

 

[Rob Mayercik]

Here's a question:

I tried the 703s in my stock 92, and found them to be way too much injector for me - ran real rich, hard starting, and severe misfire.

When I reached out to the seller I bought them from and described what I put them in, he agreed they were over-flowing and swapped them out for a set of the yellow 746s (the 746 is apparently rated for 19lbs/hour at 43.5 PSI, to the 23 for the 703s).

I have the original ones back in right now (seeing as doing that confirmed that the injectors were my culprit), but I'm trying to get a good handle on how these new units match up to the OEM ones, other than the obvious difference of the 746s being 4-hole, before I go putting them in.

Thoughts?

 

[SolarBell]

For what it's worth I just picked up a set of the refurbished 0280156007 injectors from injectors4u.com and got them put in today. So far so good, and the bright green color is amusing in my dirty black engine bay.

 

[freday2005]

The Bosch 0280155703 injectors will spray 24lbs/hr of fuel at the cherokees 49psi rated fuel pressure. The stock injectors are rated at 23.7lbs/hr at 49psi. If you call bosch (like I did) and take the time going through 4 or 5 reps until you get someone that really knows there fuel rating formulas you will find these injectors are rated at about 21lbs/hr at the common rating of 43.5psi that all injectors are rated at. After about a half hour on the phone and several reps I got a guy that was willing to figure out there rated flow at 49psi that my 97XJ uses, and its 24.41lbs/hr. In comparison the stock EV1 injectors that come on my cherokee are rated at 23.7lbs/hr. Everyone on here arguing about 24lbs/hr injectors for strokers are thinking of the mustang injectors which are rated at 24lbs/hr at 43.5psi. Again 43.5psi is the standard fuel pressure that injectors are rated at so manufacturers have a standard to work from when doing their own math to match fuel needs. If these injectors are way over rated why would they be in 2.4L dodge engines? ******* Correction stock injectors are rated at 21lbs/hr at 39 psi which works out to 23.538~lbs/hr at 49psi and the 703s are rated at 23lbs/hr at 43.5psi which works out to 24.41~lbs/hr at 49psi.******* Just found my notes. The jeep has a Long Term and a Short Term fuel trim table. It learns the LONG term table over time and uses that table to adjust its base mapping, the SHORT term trim is what it is currently using when adding or removing small amounts of fuel for current load and throttle position. The ECU should have no problem adding or removing up to ~10% trim from the LONG term table to learn the 703 injectors. The first half dozen - dozen warm up cycles it WILL run rich and have HIGH short term trim numbers. As it learns the new fuel map the LONG term table will be modified with a multiplier for correcting for the new injectors and the SHORT term trim numbers will come down.

 

[Talyn]

Everyone on here arguing about 24lbs/hr injectors for strokers are thinking of the mustang injectors which are rated at 24lbs/hr at 43.5psi. Again 43.5psi is the standard fuel pressure that injectors are rated at so manufacturers have a standard to work from when doing their own math to match fuel needs.

Wrong.

If these injectors are way over rated why would they be in 2.4L dodge engines?

A variety of reasons dictate what injector they use. Not just the fuel flow. For example both the 4.7L and 5.2L/5.9L engine use injectors that flow ~24 at the fuel system pressure. The PCM is tuned for the correct injectors.

 

[1sicto]

So sre we still using the old neon injectors on 97's or no?

 

[SuperB60ce]

Wrong. A variety of reasons dictate what injector they use. Not just the fuel flow. For example both the 4.7L and 5.2L/5.9L engine use injectors that flow ~24 at the fuel system pressure. The PCM is tuned for the correct injectors.

Talyn, what injectors would you recommend for a 1996 4.0L

 

[jhc7399]

A 96 would use 703's.

 

[voudoux]

I have 2.5 4 cyl does the same ingector sizes apply it is a 1998 should I use a 703 or what any help would be great. Thanks