Injectors

[RenoF250]

Why no injector section in the FAQ?

It seems most are running the Ford blue top injectors, why not the Mopar 53030262? The blue tops are 24 lb./hr. at 39 psi, the Mopars are 24.6 according to this:
http://users.erols.com/srweiss/tableifc.htm

Scaling the injectors with displacement you need a little bit more than 24lbs. - (21/4.0) + 4.6 = 24.15 not a big deal but I have read some say the 24s were not doing it for them. Also, I can get the Mopar injectors for $26 each new. Anything wrong with using these?

[Alexia]

What fuel pressure is your Jeep's system running at?(Or what year is your engine's setup?)

[RenoF250]

What fuel pressure is your Jeep's system running at?(Or what year is your engine's setup?)

It is a 1994 so I think it is 39 psi correct? I plane to make it adjustable though.

[RenoF250]

Here is a great link on injectors:
http://www.ausjeepoffroad.com/forum/sho ... hp?t=92236

I am thinking I will go with the 2001-02 Camaro, 2001-04 Corvette LS1 injectors 0280155931.

[RenoF250]

What fuel pressure is your Jeep's system running at?(Or what year is your engine's setup?)

It is a 1994 so I think it is 39 psi correct? I plane to make it adjustable though.

I just ordered the higher pressure regulator for $20 so it will be 40-48 psi. That will get the stock injectors to 24.8 lbs./hour. I will see how that works and keep an eye out for the Camaro injectors. I can get them rebuilt for $35 so I may just go that way.

[rainman]

Kicking up the fuel pressure on the Oem pintal injectors can be counter productive:

Effects of Fuel Pressure on Pintle Type Fuel Injectors.

Fuel velocity through a pintle type fuel injector [type code EV 1] can dra-
matically affect its ability to atomise fuel. The profile of the pintle used in a
fuel injector has a direct relationship to the operating pressure it is designed
to operate under. Whilst Bosch produce various fuel injectors that may flow
the same amount of fuel at a given specification, the system operating pres-
sure will influence the pintle profile. Correct pressure will result in a well
atomised spray, while insufficient pressure will result in a “hosing” effect.
Excessive pressure will result in either “hosing” or a spray angle that is too
large for the targeted area dependent on the pintle profile.
The consequence of excessive fuel pressure on a pintle type injector may
well be that as the pressure is increased the mixture values of the engine
may appear to get leaner. This is of course not the case, but the fuel being
injected is no longer atomised and is entering the cylinder as a liquid mass.
This will typically cause the Hydrocarbon [HC] values to rise due to the raw
fuel exiting the cylinder, and the Carbon Monoxide [CO] to drop due to
insufficient combustion.
Later design fuel injectors [type code EV 6] use “director plate” multi-ori-
fice technology to better atomise fuel across various operating pressures.
These injectors allow more flexibility in relation to operating pressures with-
out compromising spray efficiency or fuel atomisation.

[RenoF250]

Hmmm so I guess I will have to get the Camaro injectors sooner. They are EV6 so they are supposed to be able to handle the pressure.

Has anyone run the stock injectors with 48 psi? The shots I saw of them running 39 psi looked like a "hosing".

[Cheromaniac]

Here's some more useful info.:

http://www.jeep4.0performance.4mg.com/tech_specs.html

[RenoF250]

Here's some more useful info.:

http://www.jeep4.0performance.4mg.com/tech_specs.html

Now I am confused, those specs and some other places say the stock are 21lbs./hr at 39 and witchhunter says they are 248cc@3bar which would be 22.4 lbs./hour. The power calculators all say that 21 would be marginal for the stock 190 HP rating so I am inclined to believe witchhunter but I cannot find a definitive source. Things on the internet tend to get copied so the number of times you see it repeated really does not seem to have a bearing on how true it is.

Running the 53030262 at stock 39psi looks like a good option also.

[Cheromaniac]

Now I am confused, those specs and some other places say the stock are 21lbs./hr at 39 and witchhunter says they are 248cc@3bar which would be 22.4 lbs./hour. The power calculators all say that 21 would be marginal for the stock 190 HP rating so I am inclined to believe witchhunter but I cannot find a definitive source. Things on the internet tend to get copied so the number of times you see it repeated really does not seem to have a bearing on how true it is.

Running the 53030262 at stock 39psi looks like a good option also.

The stock '91-'95 injector flow rating of 21lb/hr @ 39psi is equivalent to 22.2lb/hr at 43.5psi (3bar) or 230cc/min. An injector flow of 21lb/hr is plenty enough fuel for a 190hp six-banger. The stock 21lb injectors in a '91-'95 Jeep become marginal at about 220hp.

[rainman]

I have 703 neon injectors in my stock 4.0 now.
Plan is to run these with an adjustable fpr on my '95 xj in a 4.6 stroker- currently being built.
If that is not enough then keep in creasing pressure. With higher rated fpr's. With an adjustable map sensor.
I have acess to a wide band E.G.O.

Failing that will be some kind of Bosch ev6 24lb injector, possibly Taurus injectors -what ever is around / costs less.

Apparently over on Naxja there are people running 703 injectors in strokers on obd2 jeeps -49 psi constant fuel pressure - and they are running fine. With out that info would have gone straight for the Taurus 24lb injectors.

Good luck with it.

[SilverXJ]

I'm running the 784s in my stroker and they are nearly a perfect fit.

[RenoF250]

I'm running the 784s in my stroker and they are nearly a perfect fit.

What are "784s"? I do not see 784 in any of the included in any of the previous p/ns. What did they come in?

[the grey ghost]

Dodge caravan, ev6 black injectors, I'm running at 41-48 psi and run awesome , perfect fit, but I'm also using split second signal modifier on the map sensor

[rainman]

703=784 with a different electrical connector. 703 ev1. 784 ev6

http://www.ausjeepoffroad.com/forum/sho ... ostcount=1