Engine 19# or 24# injectors?

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
I have everything already except for the Mass air injectors currently. Getting ready to swap in a new motor. Trying to decide if I need to go ahead and use 24# for this or if 19# 4 hole type injectors are fine. I dont plan on doing any "major" upgrades later, maybe small stuff but no power adders. And will the smaller new style injectors work on a 1993 or do I need the larger around bosch style? Ignition is currently stock distributor and coil with frpp wires. May upgrade to msd stuff later.

Stock block with fresh rings and bearings
E7TE heads Professionally ported with 1.94/1.60 valves
E303 cam
Trick Flow Track Heat Intake
BBK 65mm EGR Spacer
65mm Professional Products Throttle Body
75mm Pro-M Mass Air sensor (Have not purchased yet)
K&N Cone Filter
BBK Fuel Pressure Regulator
Flowtech Long Tube Headers
Flowtech Off Road H pipe for 3 blolt flange long tubes
EGR Blocked off / Smog pump removed
Electric Fans
Underdrive Cobra Crank Pulley
Aluminum Radiator & 180 thermostat
 
Last edited:
  • Sponsors(?)


Hoytster

I don't dare do that to my Knob
10 Year Member
Dec 30, 2002
874
548
134
37
Cornwall, PA
www.hoytspot.com
You can use the thin body 4-hole EV1 injectors in place of the 1-hole wide body EV1 injectors. I'd recommend it as the the 4-hole injectors have some benefits including a better fuel atomization.

I would run 24's on that combo if you are running stock fuel pressure. 19's will work but you will be pushing them past the 85% duty cycle that I always try to stay under.
 

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
I am getting a gauge with the BBK FPR however I have no idea where I should set the pressure with either injectors. I was going to do 4 hole with either style but to be clear I am able to run the attached style?
 

Attachments

  • Like
Reactions: Hoytster

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
27,961
10,225
224
Box behind Walmart
www.stangnet.com
I on the other hand would stick with the 19s.

I ran a very similar combo many moons ago. It ran on SD until the MAF conversion. The 24 lb injectors will have [some] driveability issues (without a tune) that you will not have with the 19s.

The 19's will give you the best chance the stock EEC has at running that combo without issues.

Do you have any method of reading Air Fuel Ratio or Lambda (such as a wideband)? This will ultimately determine your final fuel pressure. In the meantime, you should set fuel pressure to stock.

What fuel pump are you running?
 

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
No wide band and I plan on upgrading the fuel pump to a 255LPH pump. The stock pump is really loud and has been for years. Still working but not sure how well. I am only worried because from what I have read the stock 19's are only good for around 300hp max and I may not reach that with this combo but who knows later. I will get a MAF that is matched for the injectors though which is why I have not ordered it either. I have a 93 Cobra MAF that I bought but probably will not put it on even though I was told it would work with my combo. Also heard it will not work right so will probably not go that route.
 

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
Oh and there is a very outside chance that I may put a 347 stroker short block in it down the road but probably not any time soon.
 

Hoytster

I don't dare do that to my Knob
10 Year Member
Dec 30, 2002
874
548
134
37
Cornwall, PA
www.hoytspot.com
I am getting a gauge with the BBK FPR however I have no idea where I should set the pressure with either injectors. I was going to do 4 hole with either style but to be clear I am able to run the attached style?
Yep, those are the thin body EV1's :nice:

No wide band and I plan on upgrading the fuel pump to a 255LPH pump. The stock pump is really loud and has been for years. Still working but not sure how well. I am only worried because from what I have read the stock 19's are only good for around 300hp max and I may not reach that with this combo but who knows later. I will get a MAF that is matched for the injectors though which is why I have not ordered it either. I have a 93 Cobra MAF that I bought but probably will not put it on even though I was told it would work with my combo. Also heard it will not work right so will probably not go that route.

You are correct, max CRANK hp with 19's is around 320. They are approaching 85% duty cycle at ~260 crank hp. I agree it would be easier to stick with the 19's, but I never like to run an injector past 85-90% duty cycle myself. If you're ever planning on going 347, the 24's will definitely be needed if not 30's. I've never had drive ability problems when running a properly calibrated MAF to the injectors, but that's my experience and others have had different experiences.

Tuning is the proper way to compensate for the larger injectors as @Noobz347 said. I haven't run a calibrated MAF since 2004, I've always tuned me ECU since then. A base model tweecer runs $300 and would allow you to program the exact MAF transfer, just for comparison to what a calibrated MAF would cost. Or you could get a basic chip from a respected tuner that would compensate. Just thinking out loud.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
27,961
10,225
224
Box behind Walmart
www.stangnet.com
Whichever pump you get, you should ensure that it is a high pressure version.

This way, if you get to the top of the duty cycle you can bump fuel pressure a pound or two and not sacrifice fuel volume.

The calibrated meters do a decent job if you purchase a decent product. Tuning is still required to bring it perfectly inline and the further away you get from 19s, the more 'out of tune' a calibrated meter will be.

If later you decide you want to add boost, you'll need to swap those injectors anyway. In my mind, I'd hold off until then.
 
  • Like
Reactions: General karthief

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,293
8,473
224
Massachusetts
If you have the 19's now, you can probably get the combo running just to iron out the kinks. But I echo what other's have said. You would be at the edge of what 19's can safely perform so you should consider 24's with that combo
 

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
I have the old stock 19's but planned on buying some new ones rather than run the 170k mile stockers. I will probably leave everything on the stock motor other than the wiring. I want the new motor to be new. I will either roll the stocker into a corner since it is truly stock right down to the valve cover gaskets. But I may also sell it complete since it still runs very well. Depends on if I want to store it and waste garage space. And whether its really worth it to the next buyer to have it. Could go a long ways towards a stroker kit.

I was looking at the Pro-M meter. Have heard bad things about C&L and others are a bit more expensive.
 

Hoytster

I don't dare do that to my Knob
10 Year Member
Dec 30, 2002
874
548
134
37
Cornwall, PA
www.hoytspot.com
I'd look at Pro-M over C&L. I had a C&L on both of my now sold 95's and tuning that thing was a PITA. I have a Pro-M on my 93 and it's been rock solid.
 

79pace

something stupid will fall out of my mouth
Founding Member
Jul 21, 2000
73
7
18
47
Tulsa, OK
www.carbdford.com
Ok, Right now I am leaning to Pro-M and 24's just to be safe. What kind of fuel pressure should I run though with the stock A9L? I have typically just run carburetors and that is much easier to figure out fuel pressure.
 

Hoytster

I don't dare do that to my Knob
10 Year Member
Dec 30, 2002
874
548
134
37
Cornwall, PA
www.hoytspot.com
Stock fuel pressure with a calibrated MAF and stock computer. It should be 38-39lbs with the vacuum line unhooked from the regulator and plugged.