Hi, I have a 1994 Ranger Splash with a 4.0L OHV it has stock injectors. I'm thinking it needs new, or Remanufactured Injectors. What will I have to change as far as Hard parts, or programming? I'm looking at Bosh 0280150931 injectors with installation kit. i'm kind of new to working on these engines, so go easy on me. I'm a Old hand as far as mechanicing, but nit on these engines. So give me the Pros & cons of this injector, please. I'm also going to change the Rocker Arms, with new parts. I have a couple that are noisy. I'd love to have more HP out of this Little engine. I have been looking into a Hotter cam, and Headers. The engine has 102,000 miles on it.

 

Injectors are not like Jets on a carb
Larger injectors don't help with more power, the computer just doesn't open them as long which can cause it to set a Rich Code.
Two things are programmed into the computer that it can't check, injector size and Fuel Pressure
If you change the size of the injectors then computer will think something is wrong, in the case of larger injectors, too much fuel is flowing in when it opens the injector for 100milliseconds, for example, so it would set a Rich code to notify driver of the problem
Same if fuel pressure should drop, computer would have to open injectors longer to get correct ratio, and in this case it would set a Lean code
In either case the computer corrects the problem in 1 or 2 seconds, so engine is never actually running Lean or Rich, those are just code words for injector open times

So you should stick with the same pound rating as stock injectors unless you will be adding a super charger or turbo charger
Cam wouldn't require injector change

You need new upper intake and fuel rail gaskets, and new O-rings, which should come with the new injectors.
I think 4.0l OHV engines use 19 pound injectors, but can't remember


Ticking noise from valve train on the 4.0l OHV is more often the lifters and you need to pull off the heads to change those

 

RonD I understand, what you are saying. I think these are the direct replacement for the "Stock" injectors. These have 4 holes instead of one. From what I've read so far is that these help atomize the fuel better, and are made to flow equally. The Camshaft and lifters I'm considering is a Competition Cams 49-422-8, Advertised Duration .270/.284, Lift .500/.500, with new Smith Brothers pushrods nh54a-dd 5.550, and a set of Headman Headers, Hed 89400. Why do you have to pull the heads to change the lifters?

 

Are the Heads that close to the lifter valley? The last one of these little engines I worked on was a 2.8L other than my 4.0L SOHC. but I haven't really been inside it.

 

Yes, heads stick out so all lifters can't be pulled up high enough to remove
I think a few can be pulled out but...........they won't the the ones ticking, lol.

Yes, better mix with the air never hurts
Fuel ratios are WEIGHT ratios, i.e. 14.7:1 air:fuel ratio is 14.7 POUNDS of air to 1 POUND of gasoline
Which is why injectors are rated in POUNDs per hour, so you can calculate what injector to use based on pounds of air being pulled into engine, which is based on engine displacement and then you can calculate the pounds of gasoline needed to be injected for weight of air

 

OK Cool, about the mixture rate, Uncool about pulling the Heads!!! Gezzzz, I guess I'll just Pull the engine. If I have to go that deep into it, I might as well build the whole thing. Because I'm sure, if I get that deep into it, I'll find other things that need attention. it does have just over 100K on it. dang it Dang it!! I have been thinking of a Supercharged 4.0L, using Super Coupe T-bird parts. LOL!! it might happen sooner, than Later!! I think I have been watching to much Youtube LOL!!

 

Reads like a fun project

Morana Racing has many "ideas" and parts for 4.0l OHV

Not sure I would "build" a 4.0l OHV unless I was racing in a 4.0l limited displacement category.
Roller rockers and cam yes, electric fan conversion yes

Personally I wouldn't do a Supercharger(or turbo), I would look at 5.0l swap, "there is no replacement for displacement"

 

Well I found my Problem !!! #5 Cylinder in the middle of the left bank, had a bad spark plug. I had a set of Motorcraft single Platinum plugs in it. 1 had the Porcelain around the electrode was Broken. no visible damage to the electrode, but it wouldn't fire. A new set of plugs, and I'm back up and running. That was throwing me a Curve, because those plugs didn't have 2,500 miles on them. What is the Correct Plug for this engine? I called 4 different places and got 4 different answers. The plugs that were in it were a Motorcraft Platinum AGSF42FM-1D. The shank is threaded all the way to the seat. the threaded part is approximately 5/8th" long. The new Plugs are a Motorcraft 765, and have a considerably shorter threaded area, but the shank itself is approximately the same length from end to seat. These plugs are cooper core, non platinum plug.

 

RonD just another question, What do you think about this? Building another 4.0L OHV 90-94, using the 90-94 Flat top pistons, then topping them off with a set of 95-97 Closed Chamber Heads?

 

If you like buying 91-93 octane fuel its fine.

Higher compression is a double edged sword, more power is released but higher heat with higher compression as well.

4.0l OHV has 9.0:1 compression ratio and 160HP
4.0l SOHC has 9.7:1 ratio and 205HP, but Ford HAD TO run an EGR system AND a knock sensor so it could run regular 87 octane fuel, and when knock sensor is active you drop down to about 185-190HP

But.........I think you only get 9.5:1 ratio with the older pistons and newer heads, so it would be boarder line.
If you have an EGR system then it should be OK

 

I usually run 89 or better in the splash anyways. I used to build 289's & 302's with Flat top pistons, and top them off with a Set of Heavily Worked 65 289 Heads. deck the blocks .010, and cut the heads .010-.020. Those heads were 48CC combustion Chambers. for a total Compression ratio of 11.1:1