So, for the 2nd time in one tank of fuel I'll be pulling the intake off to deal with injector vacuum leaks.
Two weeks ago (we don't drive it much) I was addressing p0171 & p0174 codes. I smoked the intake and found the seal leaking on #1 injector.
I pulled the upper intake to address that and the oil leaking valve covers.
When I pulled the fuel rail & injectors I noted that 3 of them had a piece missing from the lower o-ring support. Looked like the plastic chipped. This is like the pintle cup on most injectors but the OE injectors just have a plastic ledge/ring the retains the lower oring onto the injector.
I replaced the orings with GM standard fuel injector orings. They were a bit chubbier and appeared to seal better in their bores.
Apparently they aren't enough as now the codes have returned and I can hear hissing at idle -which isn't smooth. Ive spritzed carb cleaner around the injectors and the idle improved.
My theory is that without that complete (none were missing the whole thing, just a few had a chip out of them) lower ledge for the oring to rest on, the engine vacuum pulls down the weak unsupported side of oring and causes ill-fitment which leads to a vacuum leak. This leads to the CEL.
SO I've found rebuild kits for the injectors (upper & lower orings, filter, and lower retainer for $21 on eBay).
But I've also looked into upgrading the injectors, not for higher flow rates, but more efficient ones or possibly slightly lower flow rates.
Ford 19lb injectors from the 4.6, 5.0, & 5.4 are a suitable match.
Any suggestions?

 

rebuild the ones you have. with a quality kit or get some. I found full set to use (rebuilt screens/seals/clean/tested/warrantied ) for $185. ford s a downgrade in rate and efficiency

 

Roger that Dusty1!

 

swapgames......on the fleabay. that's what I have now and I just put a second set in my rail to test in the new engine.


you need 3? I might have 3, but i'd still want to swap all if they have started their demise. let me know....I can prolly send you 3 --5.....not sure what I have, but I have that.

 

Thanks is Dusty1, I ordered the rebuild kit which ended up only costing $4.75 for all 8 due to some Ebay bucks I had accrued!

 

had mine cleaned and tested and they were all within 3-4%. I used injectorrepair.com ... Super helpful I purchased ford 19# thru him and didn't realize they wouldn't fit. I called him after I got them and he room them back with mine and was just very knowledgeable

 

I rebuilt the factory injectors (102k miles on them) using a kit off ebay. It included upper and lower o-ring seals, filters, and lower seal retainers.
I clamped a wood screw in the vice, threaded the injector inlet onto it only a couple careful turns and pulled out the old filter. I cleaned out the injector with carb cleaner (2+2 Gum Cutter from NAPA).
Using a small hammer I installed the new filters.
The old lower o-ring retainers were chipped and two fell apart during removal. I removed all of them and after mounting on the new orings.
Each were lubed with Vaseline prior to install.
After the fuel rail was assembled and installed, I sprayed down each of the injectors with 2+2 and blew them dry.
I then sprayed each base liberally (dripping) with 500° Safe Clear engine enamel.

 

I rebuilt the factory injectors (102k miles on them) using a kit off ebay. It included upper and lower o-ring seals, filters, and lower seal retainers.
I clamped a wood screw in the vice, threaded the injector inlet onto it only a couple careful turns and pulled out the old filter. I cleaned out the injector with carb cleaner (2+2 Gum Cutter from NAPA).
Using a small hammer I installed the new filters.
The old lower o-ring retainers were chipped and two fell apart during removal. I removed all of them and after mounting on the new orings.
Each were lubed with Vaseline prior to install.
After the fuel rail was assembled and installed, I sprayed down each of the injectors with 2+2 and blew them dry.
I then sprayed/soaked each injectors base (where it was sunk into the intake) liberally with 500°F safe clear engine enamel. This is an old trick used to seal vacuum leaking injectors but I'm using it as extra insurance.
P0171 and P0174 codes cleared and have not returned.
Idles smoothly and overall runs the best it ever has.
So! If your injector's lower o-ring is sitting on a cracked, chipped, or missing support ring (or pintle cap) replace them! Vacuum may be sucking that oring wonky and causing unmetered air to enter the intake leading to rough idle, hard starts, and of course the SES CEL MIL check engine light to be on.