upgraded injectors

[512tr]

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.

 

 

87manche,

No I haven’t, the reason I tested the HO injectors was that I did have them in my garage.

 

Have never used an adjustable MAP sensor, but as I understand I could have used one

if the engine has been running lean with the stock injectors, and rich with the HO injectors.

 

Then an adjustable MAP sensor may have been the solution to trim down the injectors bandwidth with the HO injectors or trim up the bandwidth with the stock injectors.

[Windowsrookie]

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.

 

 

If that is true, why does Precision Auto Injectors list 87-95 as compatible? Should I stay away from them?

 

http://www.precisionautoinjectors.com/p ... roductId=7

[BLHTAZ]

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.

 

 

If that is true, why does Precision Auto Injectors list 87-95 as compatible? Should I stay away from them?

 

http://www.precisionautoinjectors.com/p ... roductId=7

They are completely compatible using the Ford injectors from Precision. I used the same ones in my '88 MJ and in our '95 YJ and am very pleased with the results. Those examples are for stock injectors and don't really have any bearing on the replacement Ford Motorsport injectors. If you go to other sites like Five-O motorsports...you will see the same listings as on Precision ;)

 

When you go to Precision, be sure to use ' JEEP ' as a dicount code at checkout for 10% off...if I haven't told you that before :cheers:

[wolfpackjeeper]

my 1991 stroker uses Lt1 injectors from a camaro. Could never get a set of FMS ones that would work well. Just another option.

 

And ruggers: you are comparing apples and oranges. Is this a turbodiesel that you upped the boost on? How did you measure that 50hp gain? Chassis Dyno or butt dyno? Did you use a power programmer of some sort when you did it? Lots of variables to that one.

[BLHTAZ]

Yea...the strokers have to use the 24lb injectors. Precision usually has some, but he doesn't always have a lot so he has not yet put them up on the site. If anyone is wanting those...email him and ask :thumbsup:

[HOrnbrod]

I use the 23.8# @ 49 PSI Chryco gray tops in my stroker. The Ford 24# ran too rich at WOT. Most all of the common injectors are made by either Siemens or Bosch. Mercedes, BMW, GM, and Ford injectors can all be used in our engines. The important thing is to get the flow rates and fuel pressure dialed in for the optimum A/F ratio across the power band for both performance and economy.

[Windowsrookie]

They are completely compatible using the Ford injectors from Precision. I used the same ones in my '88 MJ and in our '95 YJ and am very pleased with the results. Those examples are for stock injectors and don't really have any bearing on the replacement Ford Motorsport injectors. If you go to other sites like Five-O motorsports...you will see the same listings as on Precision ;)

 

When you go to Precision, be sure to use ' JEEP ' as a dicount code at checkout for 10% off...if I haven't told you that before :cheers:

 

 

You have to select a year for the 5.0 injectors on that site. What year should I select?

[BLHTAZ]

They are completely compatible using the Ford injectors from Precision. I used the same ones in my '88 MJ and in our '95 YJ and am very pleased with the results. Those examples are for stock injectors and don't really have any bearing on the replacement Ford Motorsport injectors. If you go to other sites like Five-O motorsports...you will see the same listings as on Precision ;)

 

When you go to Precision, be sure to use ' JEEP ' as a dicount code at checkout for 10% off...if I haven't told you that before :cheers:

 

 

You have to select a year for the 5.0 injectors on that site. What year should I select?

If you are going to this site... http://www.precisionautoinjectors.com/p ... roductId=7 ...I don't see where you have to select a year and have never heard that before. It is set to '87 - '95 automatically. If it is asking somewhere after the first screen then put in the year of your Jeep :thumbsup:

[chunks6067]

i got a set of 8 from a guy at a 5.0 swap meet (good place to look)

cost me a whole 6pk of bud light :cheers:

new rings and caps working for 3 years now no problems

[BLHTAZ]

i got a set of 8 from a guy at a 5.0 swap meet (good place to look)

cost me a whole 6pk of bud light :cheers:

new rings and caps working for 3 years now no problems

I did that too, but there was no change in performance, MPG or anything because you are getting dirty used injectors. The benefit of buying from someone like Precision is that they are basically a new injector and have been completely cleaned, new filter installed, new orings, new caps as needed and they have been flow matched to provide the best economy and performance. When I went from the used Ford injectors to the ones from Precision, I saw better / smoother idle, slightly quicker start up, better accleration and a 14% increase in MPG. MPG gains will vary, but there is always an improvement with these :thumbsup: :smart: