upgraded injectors

[DansGreyMj]

i heard of people using 5.0 mustang injectors and was wondering if this was true, what year mustangs, what kind of gains and what other injectors can i use

[Cabz]

on my 88 MJ 4.0 , I used ford 19lb/hr injectors . I got the set off ebay for about $150.00 brand new . They work a bit better than the stock Injectors.

 

you can also use HO jeep injectors 94-97's I believe are also 19lb'ers

[Oizarod115]

i thought HOs ran 21lb/hr or something different?

I'm also running the 5-0 19lb/hr injector...

they have a better spray pattern which supposedly helps with efficiency and such. but i didnt notice much gain. however they cost about the same so just go for it.

five-omotorsports.com (i got mine there they know exactly what the heeps need they get 4.0 customers often)

[Cabz]

i thought HOs ran 21lb/hr or something different?

I'm also running the 5-0 19lb/hr injector...

they have a better spray pattern which supposedly helps with efficiency and such. but i didnt notice much gain. however they cost about the same so just go for it.

five-omotorsports.com (i got mine there they know exactly what the heeps need they get 4.0 customers often)

 

strokers run 21-24 lb'ers.

I think the 2000+ engines use a 20 or 21 lb er , I'm not sure .

Of course I is to Poor to own anything that new anyways :D

[Oizarod115]

 

strokers run 21-24 lb'ers.

I think the 2000+ engines use a 20 or 21 lb er , I'm not sure .

Of course I is to Poor to own anything that new anyways :D

 

that mustve been where i got that.

(noone in my immediate family owns anything newer than a 95 jeep )

[DansGreyMj]

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

[randimal]

The Mustang 5.0 ones are the only ones I've heard of. The HO ones have the wrong rate. I got used ones off ebay. 8 for 15 bucks. Picked up new O-rings at the dealer for a few dollars. They work fine. I can't guarantee anything, but I've heard people say they are good for 3hp or so.

[512tr]

Here's the Jeep injectors.

 

Model Year, ...Part #, .......Colour, ....Fuel Pressure, ...Static Flow,

'87-'90, ........53003956, ...Dark Tan, ...39psi, .................18.6lb/hr

'91-'93, ........33007127, ...Brown, .......39psi, .................21.0lb/hr

'94-'95, ........53030343, ...Tan, ...........39psi, .................21.0lb/hr

'96-'99, ........53030778, ...Grey, .........49psi, .................23.2lb/hr

'99-'01, ........04854181, ...Blue tip, .....49psi, .................22.5lb/hr

 

If you increase the fuel pressure to 43psi the stock '91-'95 4.0 injectors are rated at 22lb/hr.

 

Other available injectors

 

Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302)

Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302)

Ford Motorsport 30.0lb/hr @ 39psi (Part no. FMS-M9593-B302)

Chevy LT1 24.0lb/hr @ 43.5psi (Part no. 17124248)

Chevy LT4 28.0lb/hr @ 43.5psi (Part no. 17124251)

Accel 19.2lb/hr @ 44.1psi (ACC-150119)

Accel 21.1lb/hr @ 44.1psi (ACC-150121)

Accel 24.4lb/hr @ 44.1psi (ACC-150124)

Accel 25.6lb/hr @ 44.1psi (ACC-150126)

Accel 29.4lb/hr @ 44.1psi (ACC-150130)

 

The '95 Jeep 5.2 ZJ/Dodge 5.9 injectors (Part no. 53030262) are rated to flow 24.6lb/hr at 39psi.

 

 

I use the -94 HO injectors with 60mm TB, cone filter and 3" exhaust.

 

Link to installation

http://comancheclub.com/forums/viewtopi ... highlight=

[Eagle]

you can also use HO jeep injectors 94-97's I believe are also 19lb'ers

Nope. Depending on year, those will be 22 or 24 pound. They'll run, but your gas mileage will go down the toilet because the ECU can't shut 'em down enough when conditions don't need a lot of fuel.

[jeepthing07]

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

 

HeadOn apply directly to the forehead! HeadOn apply directly to the forehead! HeadOn apply directly to the forehead!

[Oizarod115]

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

 

HeadOn apply directly to the forehead! HeadOn apply directly to the forehead! HeadOn apply directly to the forehead!

....?

[feerocknok]

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

thats crazy my mj is the only car that is pre 99 in my fam, with an 06 f350 being the newest

 

HeadOn apply directly to the forehead! HeadOn apply directly to the forehead! HeadOn apply directly to the forehead!

....?

 

It's a horrible commercial. I don't even know what the product is, cause that's all they say. http://kevinbyrd.com/films/headon_h264.mov

 

How do you figure static flow if the fuel pressure is altered?

[512tr]

How do you figure static flow if the fuel pressure is altered?

 

 

Use this formula:

 

[Regger]

Hey Folks,

 

A few of you have mentioned about increasing fuel line pressure... HOw does one go about doing this?...

 

I'm thinking of upgrading my injectors to try and get a little more umph.. out of the MJ.. I don't care too much about fuel economy ( as long as its not in the single digits for mpg) as this will be a trail rig..

 

Thanks,

Ryan

[512tr]

Hey Folks,

 

A few of you have mentioned about increasing fuel line pressure... HOw does one go about doing this?...

 

I'm thinking of upgrading my injectors to try and get a little more umph.. out of the MJ.. I don't care too much about fuel economy ( as long as its not in the single digits for mpg) as this will be a trail rig..

 

Thanks,

Ryan

 

In order to increase the fuel pressure you have to install a new fuel pressure regulator, mainly an adjustable regulator.

 

By reducing the fuel going back to the tank, the pressure in the fuel rail increase.

 

However, increasing the fuel pressure or installing bigger injectors to a non modified engine is just waste of gas, and the performance will most likely go down.

 

You will run too rich in open loop conditions, and the oxygen sensor will have a fight to keep the AFR around 14,7:1 in closed loop conditions.

[yj2mj]

I've got a set of Ford 24 lb injectors to go in the stroker I'm currently building.

[Regger]

 

In order to increase the fuel pressure you have to install a new fuel pressure regulator, mainly an adjustable regulator.

 

By reducing the fuel going back to the tank, the pressure in the fuel rail increase.

 

However, increasing the fuel pressure or installing bigger injectors to a non modified engine is just waste of gas, and the performance will most likely go down.

 

You will run too rich in open loop conditions, and the oxygen sensor will have a fight to keep the AFR around 14,7:1 in closed loop conditions.

 

Okay, then why do I hear of people all the time installing bigger injectors on their stock motors?... I know you have to for the strokers, but for the stock motors, its just a waste of time, money, and fuel???..

 

I KNow on my Cummins Diesel, it mad a huge difference, 50HP injectors gave me just that... yeah I lost about 1mpg, but it sure gets out of its way real fast now!!!

 

My main reason for wanting new injectors, is that mine have been sitting for a few too many years and were on their last legs before the truck went into storage... so I figure, when it comes out fo storage, I might as well put in new injectors, and figured why not go with something that would net a little more HP to turn the big meats it will soon be sporting

 

Thanks,

Ryan

[Oizarod115]

i did the five-o injectors not to boost HP but because mine were spraying more OUT than IN the cylinder... which causes all sorts of problems. like fireballMJs. (at least id have a cool username :brows: )

 

but yeah IIRC the 5.0 injectors cost alot less than the renix ones. (HO injectors were dirt cheap the renix i found were not)

[512tr]

 

In order to increase the fuel pressure you have to install a new fuel pressure regulator, mainly an adjustable regulator.

 

By reducing the fuel going back to the tank, the pressure in the fuel rail increase.

 

However, increasing the fuel pressure or installing bigger injectors to a non modified engine is just waste of gas, and the performance will most likely go down.

 

You will run too rich in open loop conditions, and the oxygen sensor will have a fight to keep the AFR around 14,7:1 in closed loop conditions.

 

Okay, then why do I hear of people all the time installing bigger injectors on their stock motors?... I know you have to for the strokers, but for the stock motors, its just a waste of time, money, and fuel???..

 

I KNow on my Cummins Diesel, it mad a huge difference, 50HP injectors gave me just that... yeah I lost about 1mpg, but it sure gets out of its way real fast now!!!

 

My main reason for wanting new injectors, is that mine have been sitting for a few too many years and were on their last legs before the truck went into storage... so I figure, when it comes out fo storage, I might as well put in new injectors, and figured why not go with something that would net a little more HP to turn the big meats it will soon be sporting

 

Thanks,

Ryan

 

According to my experience and testing, bigger injectors on a STOCK engine, is waste of time, money, fuel and……performance.

 

After I bored the TB to 60 mm, put on cone filter with heat shield and put in HO injectors the performance definitely increased vs. the stock TB, filter and injectors.

(Later I found out that the performance was even better going back to the stock injectors)

 

Recently I did an AFR analyze with the new set-up, I found the AFR was fare too rich with the HO (21 lb/hrs) injectors.

 

Then I replaced the HO injectors with the stock (18.6 lb/hrs), and did an other AFR analyze, the new analyze showed that the stock 18.6 lb/hrs deliver enough fuel for the 60mm TB and cold air cone-filter setup.

 

The min. AFR with the HO injectors was down to 10.2 at WOT vs. 12.0 with the stock injectors.

The mixture with the HO injectors was so rich that the O2 sensor was not able to correct (lean out) the AFR to 14:7 in Closed Loop, it stayed as low as 12.1 AFR in cruising.

 

 

In general the best performance for a normal aspirated engine, is at an AFR around 13-12 AFR at WOT, so when the HO injectors gave 10.2 AFR it was fare too rich.

 

Here is the chart showing the AFR curve for the HO vs. stock injectors.

 

 

I did some road tests, run the same distance with fixed start and stop points.

 

When I reached the starting point I was cruising at 100 km/h (62mph), when passing the starting point, I floored the pedal and run at WOT to the next measuring point.

 

With the HO injectors I reach 154 km/h (95mph), and with the stock injectors I reach 160 km/h (99 mph) at the stop point.

 

My conclusion is that the performance with stock injectors is better than the HO injectors, even with a bored TB and free flow cold-air setup.

 

Didn’t measure the MPG with the HO injectors, but based on AFR a lot of gas was just going down the drain.

 

The need for bigger injectors and increased fuel pressure first appears when serious engine modifications are done, as major head work, stroking or forced induction.

[Oizarod115]

the moral of this story is...

either go with the renix injectors. or 5-0 injectors. as theyre both the same lb/hr rate.

don't use one with higher lb/hr or lower.

IIRC the 5-0 ones are cheaper for a set but i might be wrong.

[XJ Maki]

Yeah the mustang 5.0 injectors are a popular swap because of the price not really because of the performance. I got a set of 8 Bosch take-outs off ebay for $35 + s/h... :brows:

[Oizarod115]

Yeah the mustang 5.0 injectors are a popular swap because of the price not really because of the performance. I got a set of 8 Bosch take-outs off ebay for $35 + s/h... :brows:

i didnt make off that easy but i remember HO injectors being dirt cheap and renix ones being a complete rip off.

[Regger]

Thats some awesome info there 512tr... now we know the true answer to the difference between what injectors do what...

 

However, I'm still a little skeptical about the true performance that bigger injectors can priovide.. The only reason I say this is from my experiance with my Dodge Diesel.... Granted we're talking apples and oranges I'm sure...

 

But in my real life experiance.. for my dodge, I installed bigger injectors... I lost 1 mpg on average for fuel economy, I get more black smoke when I'm hard on the throttle, but gained over 50HP at the rear wheels.. And to me, that was well worth the money, and the loss in fuel economy..

 

Not I'm not up on the gas performance... I was quite happy with my MJ when it was my Daily driver, but since buying my Dodge, and doubling the horsepower and torque, I've kind of got the performance bug.

 

My MJ is no longer the DD, so fuel economy is not a huge concern, granted I don't want to be stopping at every gas station either... But now that I will be turning some 36" meats, I'd like to give it a few extra ponies under the hood to help it turn those tires...

 

So to make my long post very short... Does the bigger injectors incrase HP?

 

Thanks,

Ryan

[512tr]

Thats some awesome info there 512tr... now we know the true answer to the difference between what injectors do what...

 

However, I'm still a little skeptical about the true performance that bigger injectors can priovide.. The only reason I say this is from my experiance with my Dodge Diesel.... Granted we're talking apples and oranges I'm sure...

 

But in my real life experiance.. for my dodge, I installed bigger injectors... I lost 1 mpg on average for fuel economy, I get more black smoke when I'm hard on the throttle, but gained over 50HP at the rear wheels.. And to me, that was well worth the money, and the loss in fuel economy..

 

Not I'm not up on the gas performance... I was quite happy with my MJ when it was my Daily driver, but since buying my Dodge, and doubling the horsepower and torque, I've kind of got the performance bug.

 

My MJ is no longer the DD, so fuel economy is not a huge concern, granted I don't want to be stopping at every gas station either... But now that I will be turning some 36" meats, I'd like to give it a few extra ponies under the hood to help it turn those tires...

 

So to make my long post very short... Does the bigger injectors incrase HP?

 

Thanks,

Ryan

 

Regger, I can only speak for myself and my findings, but my MJ is not my DD so high MPG was not my target when I bored my TB , changed injectors and did the cold air setup….only performance.

 

Emission wise I think some engines (diesels) are tuned to run on the lean side in order to satisfy the emission tests, bigger injectors these engines may increase the HP …..but NOT on the stock 4.0 Renix engine.

 

As mentioned the maximum performance on a normal aspirated petrol engine, is 13-12 AFR at WOT, AFR below this (11-10) will not be as powerful as the 13-12AFR.

 

The AFR analyze curve shows that the AFR is to low and the theory says less performance, also my road testing shows that the performance is better with the stock injectors.

 

So belive me, if the performance was better with the 21 lb/hrs injectors I would never replaced them with the stock ones.

 

I did some road tests, run the same distance with fixed start and stop points.

 

When I reached the starting point I was cruising at 100 km/h (62mph), when passing the starting point, I floored the pedal and run at WOT to the next measuring point.

 

With the HO injectors I reach 154 km/h (95mph), and with the stock injectors I reach 160 km/h (99 mph) at the stop point.

 

Note! This is not the trucks top speed, but the speed passing the fixed measuring point.

 

 

Did the same run with my bone stock -92 XJ HO (with 77K miles) and reached 155km/h (96 mph)…my ol Comanche is faster than the -92 XJ :brows:

[87manche]

diesels respond to more fuel because of the basic engine design. The throttle on a diesel doesn't restrict air, it restrcts fuel, more fuel=more power in a diesel, until the combustion chamber pressures pop the block, or the EGT temps get high enough to toast the turbo.

 

512tr:

Had you tried an adjustable MAP sensor when you did the AFR readings? Using the larger injectors and then "throttleing" them back with a lower MAP reading might have been the ticket to making those work. Of course at WOT the ECU would still open them wide, so WOT you would have been rich.