Engine 19# or 24# injectors?

79pace

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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
 
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Hoytster

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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

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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?
 

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Noobz347

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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

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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

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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

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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

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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.
 
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Mustang5L5

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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

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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

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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

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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

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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.
 

KRUISR

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I was running stock (used) Explorer injector for the last 3 years with no issues in 2 combos. First combo was E7 heads (smoothed exhaust ports), Explorer internal EGR upper and lower, stock cam with 1.7rrs, 65mm TB and stock EGR, electric fans, 3 core OEM style rad, 180 t-stat and C&L 73mm MAF with clear tube, MAC equal length 1-5/8 header and full 2.5 catted exhaust. No tune, just stock A9P computer. Never dyno'd but believe it was producing about 300 at crank. Ran this for 2 years and 15000 km.

Second combo (current combo), stock short block with 3-bar GT40s with smoothed intake and exhaust ports, added a Crower 15512 cam with 1.7rrs, 70mm TB and EGR, same stock Explorer intakes, same Explorer injectors, changed to a 76mm C&L with flow tube of my calculations, cooling system and exhaust same as before. I added a dual wideband (one for each side of the exhaust), and an Anderson PMS (only used for monitoring so far - tuning plans this summer). I believe this combo is in the 330-360 range at the crank.

What did I find... current combo at higher RPMs (4500+) would push Explorer injectors to 95% duty cycle (as read off PMS) and wideband said AFR was low 13s/high 12s at the time. So that means it was okay but not ideal. It had no idle or drivability issues. I have an adjustable FPR set to about 38psi with vacuum disconnected, My fuel pump is a stock 340lph from a Lincoln LS with a modified Fox tank mount.

I have since changed the injectors (purely for the duty cycle reason) to a set of 24 lb Cobra style I have had sitting around for years waiting for a project. I changed the flow tube in the 76mm (again to my own sizing) and it starts and runs nice. I have not had it out for a drive yet due to winter (did the change in November).

Don't fear C&L and I would recommend the 73 or 76mm units. ( I have a 73 and 80 on my shelf besides the 76 on the car).

Keep us informed of your progress.
 
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