Pliant

Actually your on the right path its just a bit elusive. As of right now its finding a tbi injector that runs at 30 psi. It may well turn out that once the engine runs you will have to recalibrate your tune to get things right. If I were you is cancel the diacom and prepare yourself for mefi burn. It's to bad you didn't order the std 17 based on what I now know the std 17 should be able to replicate the original injectors. With the burn program one could have recalibrated the file on the water and improved overall performance quite a bit. The drauma continues.

Posting from A cell phone sucks but the bourbon and wings are great.

nunnink23

I don't think they will let me return it. It's already been shipped. My end goal is not to alter the factory programming, simply because I don't want the next owner to go through this. I can give them all the info they need on the MEFI IV and injextors but once you tell somebody it has a custom program I feel like they will be leery of the purchase. I hope to get a bigger boat in two years. I go places a lot and like to stay the night. So extra space will help. And I want more power!

Edit: just thinking about that, the TJ 11's seemed to hold up fine to 30 psi but i am very confident they were not spraying enough fuel. What else would explain my poor cold start, which can be fixed with extra fuel ?

Once it's running I'm pretty sure it's lean still, since it doesn't stumble or run rough and miss like it would if it was rich. It bogs really bad and has a hanging idle after revving.

Pliant

So you better understand what's going on

1 Tj11 injector delivers 85lbs @......13 psi
2. tj17 injector deliver's 55 lbs @.... 13psi

Your mefi system is delivering.... 30lbs of pressure.... not 13lbs..... below is a decent read and a flow calc.The injector tj11 was flooding the engine badly

The tj17 can be used as a 4.3 injector @ 13 lbs or a 454 injector at 30lbs thats been the whole confusion Gm did this in 94/95 note the ebay retailer stating in large letter's HIGH PRESSURE AT 29 LBS. With one disclaimer did Standard build that replacement injector to the same standards so to speak as the original GM injector..

http://www.rceng.com/technical.aspx

http://www.summitracing.com/parts/sm.../applications/

Check the application charts out notice the narrow years GM used that injector and noteably the 7.4..... the years of the high pressure fuel pumps

http://www.dynamicefi.com/TBI_Fueling.php

•2.8l and 3.1l engines: 33 #/hr
•4.3l engine: 45 #/hr (note: some units have different flow rate injectors. This is done to help with fuel distribution.)
•5.0l engine: 55 #/hr
•5.7l engine: 61, 65, & 68 #/hr.........................................
•7.4l engine: 46*, 75 & 81 #/hr.


Again here's the speed bump you have been running into note the yr model again...

*Just watch for the '94 - '95 BBC truck units as the injectors only flow 46 #/hr at 13 psi. Which is 74 #/hr at the 30 psi these TBI units use. On the up side they come with a 30 psi FPR. The down side is that the injectors are small.

And some more for future reference they are speaking to this issue

http://www.gearhead-efi.com/Fuel-Inj...und-injectors&

nunnink23

I will read it in a bit, but if the TJ11 was flooding it, wouldn't I see fuel on the plugs? They are BONE dry when cranking. I don't doubt what you are saying, I am just so confused with this lol.

Pliant

Well hopefully your injector was on full overload it simply could not deliver that much fuel at 30 psi the flow would have been huge again they simply stalled. One of tbi short coming's was and is being able to deliver high volumes of fuel to support high horsepower engine's and air of course...if it had flowed that would be a new benchmark in tbi injectors...So let's hope im right...

Ok below is a example of how much injector you had going on there...note the displacement

http://www.azspeed-marine.com/asm496mahest.html

63 lb/hr or 80 lb/hr injectors. Optional programming to run on 89 octane pump gas.

Basic tbi function

http://chevythunder.com/gm_throttle_...ction_pg_1.htm

One thing about tbi, is that if you suspect a faulty injector, you can hook up a timing light and point the beam at the injector and see the spray pattern, and see whether or not it is correct or not.

raisingkane

It has a hanging idle after revving? Have you checked for vacuum leaks? Iv lost track on its forum. Carb clean around the intake and throttle body. Or a smoke test.

nunnink23

To be honest no, I meant to check but never did. I figured with good vacuum I didn't need to check, but I will check that when I am at the boat. I keep trying to remember to check.

Edit: I should also mention that yes, it does have a hanging idle, but not when revving in neutral. I noticed it the most on the water test, after trying to increase above idle speed. When I returned to idle, I needed to blip the throttle a few times to get the idle to settle down.

SB

Here's some ACDelco Injectors I found under the radar. It lists 94-95 7.4L truck.

Do some searching and see if this # is interchangeable.

ACDELCO Part # 2172282
http://www.rockauto.com/catalog/rafr...ktemplate=true

SB

Off ACDelco's Site:
217-2282
http://parts-catalog.acdelco.com/cat...&parttype=2682

Tail_Gunner

Expensive little bugger's but they should be very close and hopefully they will fire, i wish he had taken a neon or timing light to observe the pulsing it would have made thing's much clearer there may be some issue as to timing since the injector's seem to que off the dist firing wouldnt that be something...

https://drive.google.com/file/d/0B3w...Z2s/edit?pli=1

Check page 30 it lays it all out

And the tj17 crosses over