I have a 96 explorer with a 4.0

and i need some new injectors really bad, how many lbs/hr injectors are stock in that thing?

 

19... same on V8...

 

are you sure about that...ive been reading and im gettin mixed results, some say 21lb/hr is stock some say 19, i know my 5.0 is 19....

 

I've helped work on a '95, '97, and '98 4.0's. All of them have 19lb injectors, so I don't see why they would change just in '96. I'll check the book when I get home (I have Ford's manuals at the house for a '96), but I am 99% sure they are 19lbs...

 

ok thanks for the help

 

It's 19 for sure but why do you think you need them? PCM has no codes that say "bad injectors". I thought I needed one or more since I had a miss and lean condition code. Ended up being bad plugs/wires and a O2 sensor. Now it's smooth a silk.

 

i know i need them, not think.

it runs like heck, throws me a check engine light and it works alot better once the stupid thing gets a bottle of injector cleaner.

 

So if you are getting a CEL, what codes are stored?

 

it doesn't always throw codes...just once in a while it does. And only when there hasn' tbeen any cleaner in it for a while. I need to get a code scanner and find out i guess.

But summit sent me some 21 lb injectors in stead of 19...grrr so i gotta send em back. i called summit and they said that they would work without any computer alterations, but i dont believe them. Anyone else think they would? And if i did want to keep the 21 lb injectors what does it cost to have the puter tuned for them, or can i get a chip?

 

Summit. idiots - at least the guy that told you that. Injectors are really tricky. It's not just a direct ratio of size to pulse width. You can't change the length of time the injector is open in direct proportion to the change in pounds/hour and get the same engine performance. There is a hysterisis that some time passes from when the injector is closed to when it is fully opened. During this period, the fule is ramped up to 19 pounds per hour. Upon closer, it's the same effect but backwards. So 500ms open is not directly multiplied to the rate/sec to get X flow. So if you change injectors and then change the computer program, it needs to be customed tuned to work correctly. And yes, if you change injectors, you have to retune the computer.

I advise against any custom tunes for this vehicle. My experience is you don't need them untill you change the camshaft to a bigger lift/duration. I really need to post my bad experience with SCT I had a could months ago. Anyway, I only got 4 HP gain from SCT's advertised 19. And for $500, that wasn't quite worth it. Sure all applications are different but I think your 96 4.0 is tuned pretty close to my 93 CA 4.0, right from Ford.

I still think you're injector change may be a little premature. Addind injector cleaner also adds hydrocarbons that can affect your A/F mix. Maybe you're running lean due to a dirty MAF and fuel injection cleaner adds a boost? That's why it's important to know what codes you have gotten, are getting and what changed in between getting them or not. What is it $250-$300 for 6 new injectors? Wouldn't you fell terrible if the problem is still there afterwards and it only took a $2.50 can of carb cleaner to fix it?

 

yeah, im gonna go pick up a code scanner, or have someone scan it for me. I have a buddy that has a code scanner (hes a profresional mechanic) and he said he thought it was injectors. The injectors are paid for and summit is in the process of getting me some 19lb/hr's should be here soon. Im gonna throw em in anyways, just cuz. But what should i do in the mean time to see about my MAF etc.

 

Oh sorry - I forgot to post these links. One is for the older Explorers but the concepts still apply. Other is, agian for older Ford EFI systems, but the concepts still apply. I've ready everypage on these sites and go back for review often. Very insightfull.

http://draco.acs.uci.edu/explorer/
http://www.fordfuelinjection.com/

 

*Update*

Put the new injectors in (Pretty easy job too i was surprised) and WOW what a difference...there was snow on the ground and on the way to the shop i couldn't spin the rear tires in 2wd....when i put them in and "test drove" it, i spun all 4 for a block. What a difference.

BTW if anyone is interested, i got them for 200 dollars for the whole set from accell.

also to add to accel's rep, i got them for my 86 flareside with a 5.0 too, and wow what a difference. I got them from www.summitracing.com and they were alot cheaper 125 dollars each from ford....

 

Glad to see it went well for you!