Aftermarket Fuel Injectors

[Talyn]

How long will it take to re learn?

About 100 miles more or less. City driving will help it learn quicker.

You must also turn the headlight switch on and off 2 times while the the cables are disconnected to clear the computer's memory.

Touching the battery leads together does just that.

 

[Programbo]

....Obviously you two have no clue and no real data to back your claims up....

It's easy to quote specs off some website and SOUND like you know what you are talking about.

Basically (Without boring everyone with flow data, pulse width, etc) WOT can't be used as a base as that is not a real world situation. Injectors typically only operate at 80% of their max output. The fuel pressure on your rail can be plus or minus X%. The output of your injectors can be plus or minus X%. Your computer and related sensors can adjust the gas/air mixture more than enough to compensate for the above X%'s. Taking ALL this into consideration the 10% or so these injectors flow above stock is dropped well below that by many factors and the remaining 5% or so is not enough (220 cc/min vs 230 cc/min? Come on!) to make much if any difference in your vehicle function. It is the 4-port delivery that makes this a good upgrade. The extra 5% or so fuel (If it's even THAT much) if anything will give a little extra kick without being enough to run "rich".

That`s about all I'll say on the subject as it's all been beat to death and the fact you don't have thousands of XJs out there throwing trouble codes and failing emissions tests should be enough. If you want to be anal and split hairs over 10cc's of fuel knock yourself out.

 

[CobraMarty]

What is the stock '98 injector rated at? is that at 43psi or 49psi?

OOPS, the stock '98 injector FLOW rated at? cc/min or lbs/hr. and at what pressure? I know stock rail is 49psi.

 

[Rainman]

Another point regarding the vagaries of flow rates that is often overlooked; the flow rates are all quoted using n-heptain. A homogeneous liquid, that will give repeatable results.
Petrol on the other hand is a veritable witches brew of many kinds of hydrocarbons, chemicals and god knows what. Different petrols can vary in flow by as much as 10% as it varies in composition, between countries, refineries, companies and even with with the seasons- summer petrol has a different composition to winter petrol.

Stock Jeep 99-01 Xj injector:
22.5lb/hr@49psi (236cc/min@337KPa)
or 21.14Lb/[email protected] (222cc/min@300kpa)

Bosch #0280155784 (22.5Lb/[email protected] (238cc/min@300kpa), which are the same as the older Neon injectors 0280155703, but with a uscar electrical connector.
this is a 7% difference.

 

[Customizer1000]

You must also turn the headlight switch on and off 2 times while the the cables are disconnected to clear the computer's memory. It takes a certain amount of key cycles (turning the Jeep on and off so many times) before it can learn the new injectors. So the more you go out take it out to drive the faster it will learn them. Just a good excuse to take the Jeep to grocery store or to run errands haha

I drive it daily so it should be fast lol

 

[Talyn]

It's easy to quote specs off some website and SOUND like you know what you are talking about.

And that is exactly what you are doing with no data to back it up.

 

[Talyn]

Bosch #0280155784 (22.5Lb/[email protected] (238cc/min@300kpa), which are the same as the older Neon injectors 0280155703, but with a uscar electrical connector.
this is a 7% difference.

The flow rates are not linear. Being 4 hole they probably flow a lot more fuel.
As I said I run the Neon 0-280-155-784 on my stroker. They flow ~24 (probably more like 25) on the 49 PSI rail. At WOT @ 5000rpm they are at ~76% duty cycles. And that is without a good tune for WOT as it is still rich and needs to be dialed back. The Neon injectors still run a bit rich(11.5:1) even on my stroker. Overall average fuel trim is -8%. They are a poor fit for a 4.0L w/ all bolt ons.

Please, show me your data instead of internet and calculated flow rates (which still don't match well) to convince me otherwise.

 

[Programbo]

Being 4 hole they probably flow a lot more fuel...

LOL Yeah if all 4 holes were each and of themselves the same size as the single hole in the stock injector. Hell, I have 12 hole injectors here that put out less fuel than a single hole stock injector.

You don't know what you are talking about, do you?

 

[Talyn]

You measured the holes? What size are they in the stock single hole and 4/6/8/12 hole injectors? LOL.

Have you ever though of the fact that the area of 4+ small holes can be greater than that of a larger single hole?

While I don't know the correct quadatic equation to correctly calculate flow rate vs. pressure, I do know its not linear, which is a lot more than you obviously know.

 

[Programbo]

You measured the holes? What size are they in the stock single hole and 4/6/8/12 hole injectors? LOL....Have you ever though of the fact that the area of 4+ small holes can be greater than that of a larger single hole?

Why do I suddenly have the desire to go to Blackburn, Lancashire?

 

[Elmateo487]

And that is exactly what you are doing with no data to back it up.

I'd say he has more data trying out tons of injectors than YOU do sitting here talking about the injectors you haven't tried.

 

[Talyn]

You must have a problem reading. I have tried all the injectors mentioned here and then some.

Some of you really need to take your arm chair speculation back to CF.

 

[Elmateo487]

You must have a problem reading. I have tried all the injectors mentioned here and then some.

Some of you really need to take your arm chair speculation back to CF.

Then where is your data saying they don't work?

 

[Talyn]

Several posts back shows the data on the stroker. I'm not even going to bother to go through my notes to look up the crap data on a stock engine. IIRC fuel trims were around -15 to -20.

 

[O-Gauge Steamer]

Why do I suddenly have the desire to go to Blackburn, Lancashire?

Then, you would know hole many holes it takes to fill the Albert Hall.

 

[CobraMarty]

You measured the holes? What size are they in the stock single hole and 4/6/8/12 hole injectors? LOL.

Have you ever though of the fact that the area of 4+ small holes can be greater than that of a larger single hole?

Why do I suddenly have the desire to go to Blackburn, Lancashire?

Then, you would know hole many holes it takes to fill the Albert Hall.

I don't know, 4000 holes?

http://www.guardian.co.uk/notesandqueries/query/0,5753,-20318,00.html

 

[X E Ryder]

703's Made My '91 HAPPY!

OK folks,

All this talk made me dizzy so I just went and bought the Bosch 703's set and threw em in, pulled the neg cable, shorted them, and have driven 22 miles so far.

My XJ starts easier, runs Noticeably smoother and has an obvious increase in performance. I drive up and down a mountian everyday for work with lots of steep and tight corners. I do have other bolt-ons, like a cold air intake, full exhaust, 62mm TB, JET chip and Super coil. No matter, this was an obvious improvement and my XJ is very happy now!

I did clean up the ports real well while I had the injectors out also. Brake clean on a Q-tip and a smooth wooden dowel for the harder stuff. I was out of carb/injector clean spray.

If you are comfortable doing this job I say go for it! I spent $100 for the set of 703's tested, flowmatched etc. I just pulled the throttle cable bracket and breather hose and was able to manuever the rail around the TB and such.

Thanks for the heads up! :cheers:

 

[Talyn]

My comments were toward the injectors on the 97+ 49psi fuel rail.

 

[Programbo]

Re: 703's Made My '91 HAPPY!

I just pulled the throttle cable bracket and breather hose and was able to manuever the rail around the TB and such.

Congrats :cheers: It`s actually a real easy swap to do. I've seen "how to" write ups that tell you to take off a LOT more than you need to to do this. As you said just remove the throttle cable bracket and the one hose and you can easily get the rail on. I've done this swap like 50 times now and if I really try and rush I can do it in 15-20 minutes from the time I open the hood until I am restarting the Jeep to check for leaks.

 

[Programbo]

My comments were toward the injectors on the 97+ 49psi fuel rail.

That being the case..How would you feel about the 0280156007 as an upgrade for the 97+ instead of the 784?