So my '92 F-350 460 has the stock injectors. I believe they are the single hole pintle which just shoots a "stream". I was thinking about replacing them (they're old and not very expensive) with the newer 4 hole that shoots the "mist". Questions I had is that these are 24lb correct?
Also will going from the 1 hole to the 4 hole be a noticeable increase in power and will it affect programming/running in any way?
Thanks,
Blaine

 

Here is the injector guide I found. This is what I have used and it seems to be correct.
Trav

 

That works to identify the injector to which lb'age it is (if that's a word lol ) but I'm more concerned with the spray patterns between the single hole and 4 hole pintle's also if using the 4 hole if that will affect anything.


But nice photo. I will be saving it!

 

You asked if they were 24lbs or not that is why I posted it.


Also I don't see what spray pattern would have to do with power or anything but I have been wrong before.
Trav

 

Yes that was one of the questions, thank you and I saved the pic lol.

 

Well with the same LB injectors, I do not think you will see a WOT power increase, but you may see a throttle response and mileage increase along with part throttle power increase.

I wonder if you went with say, 30LB injectors if the ECM would be able to drop the injector pulse width to compensate in normal driving? This along with an adjustable FPR could have some good gains WOT as these trucks are very lean with the pedal down.

 

The pintle technically still shoots a conical spray, although the 4 hole nozzle is probably better atomizer. This is sort of a moot point, however, since the injectors batch fire at a closed valve. I've run both, no changes. Going from old crusty injectors to new ones though; that's where there's room for noticeable improvements.

 

Unfortunately 30 lb injectors would actually make it run leaner, but I damn sure wish it was that simple.

Afpr is a good way to play with the a/f though, and can be used to help across the board....with a wideband and some tuning of course.

 

I don't think mine are too bad, 107,xxx but being 22/23 years old and cheap enough to replace. I'm thinking about replacing both pumps and injectors.

 

Just don't buy some junk injectors. Your 22 year old injectors, if working well, are way better than some cheap junk.

 

How would that work? If the ECM is looking at O2 and adjusting for normal driving and then under WOT it reverts to a predetermined pulse width right? So shouldn't larger injectors spray more fuel with the same pulse width and pressure?

I am admittedly uninformed on this because the modified GM cars I have had with FI did not need more injector and I never had to change them. I had a 02 SS Camaro 6spd that ran 12.97 on motor stock, 12 flat with some mods and deep into the 11s on a small shot. Never needed anything done to the fuel LOL.

 

The only time I've had experience with swapping injectors of speed density with no tune is on my truck, and if you google larger injectors on factory speed density, everyone swears up and down it runs stinky rich.

My experience was a stinky mess in open loop with 24# injectors and my 351 computer but in closed loop my afr was haywire, up and down up and down. The "up" (higher value) afr lingered for a few seconds then it'd drop richer/more normal then shoot back up to lean. Under hard throttle, but still closed loop, it'd shoot scary lean (high teens and even twenty) on these intervals. Moral of the story, it spent more time lean than rich.

It ran pretty poorly but i guess I could have tolerated it. My only explanation is that the computer was doing everything it could to lean it out but was outside it's ability to do so proficiently so it went wild lean at irregular intervals but long enough to get substantial readings.

All maf cars I've swapped injectors in with no tuning were indeed rich, but I've never spent anymore time on them further than moving the car around before it was time to tune.

Them stock ls1 6 speed cars are somethin else aren't they? I ran 12.7 with drag radials and stupid teenager bolt ons, and had by no means drag suspension (setup for road courses). Gt mustangs finally broke 12's...almost 20 years later lol.

 

Ok, So just put the same stock ones in correct? as far as the stock single pintle vs the later like '97 4 hole pintle, any difference?

 

Nope, find a matching set of 24s and bolt em up. Pintle or 4 hole. If you are curious if there's a difference in feel, pull da Trigga on da fo ho.

 

^LOL

The LS cars and trucks are ridiculous. 18* cathedral port heads do that sort of thing.
I had 9 Z28s from 84s up to 02. All were modified to some degree. This is where the "ponykilr" moniker came from. I had a 94 that was a beast too. To my knowledge, I may have been the first person to change cams on a tuned port car back in 86. I built a truck block 5.7 for it. When I called Comp, they said don't do it LOL. I called Edelbrock and they made a recommendation. I bought their cam, lifters and springs and it ran awesome and had a slight lopey idle.

My 02 was stone stock with factory tires and paper air filter when I ran that pass at Fayetteville Motorsports Park. I left at 3K hard (they track prep very well there) and the rest is history.

I have some buddies with stroker LS cars that make crazy numbers on chassis dyno. Bolt in 12 bolt rears and slicks required to really air them out. I am glad I am out of that stuff, too much money and too much trouble to get into.