Check those fuel injectors

Yeah I went with single hole OEM Siemens injectors. I believe the consensus is that the computer just compensates for the extra fuel from 4 hole...but at some point I assume it just can't be turned down more. I paid a little extra for the tested and verified pattern ones.

-Mac
 
The PCM cares not about the number of holes, but rather the flow of fuel through the injector. 1 hole or 4 if the flow is the same the PCM will not care. If you go to 24# or larger it will attempt to correct at idle and cruise. At some point it cannot correct any further and you will get a code. FWIW the single jet injectors were typically used on engines with a single intake valve and designed to inject fuel on the backside of the intake valve to atomize the fuel. Multi hole injectors are more commonly used on engines with 2 or more intake valves where the fuel needs to be split between multiple runners. Not always, but look at the OEMs and that is the trend.
 
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I bought and highly recommend the DEI kit...even comes with new O-rings.

IMG20230809210841.jpg


-Mac
 
SSTJ said:
Thanks. What is the DEI kit? Sorry if it's mentioned earlier in this thread; I'm reading several at the moment. And is the purpose of this tape to protect the fuel rail from heat?
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Protect from heat...the rail and the injectors.

$75. On our 1600 mile victory lap after rebuilding my Jeep the only code I got was injector 6...not a misfire. It was really hot...100 plus a couple of days and low speed bumpy driving.

Ordered this kit when I got home. Still had issues, but no regrets because I know it'll solve other issues down the road.

Two other things I fixed...the cat was plugged...so I replaced that with a butchered together set of stainless pipes... exhaust downpipe was also hitting the front driveshaft. Front O2 sensor died, replaced that.

Jeep is running much better now...but I'm getting what I would call a lean stumble.

Last problem is fuel pressure is 35-38 psi and I believe it should be 43. New regulator coming next Thursday and it's probably the last one we'll get from Custom.

I swore I put the new one into my Jeep on the rebuild...but seeing as how the back end was hit so hard it snapped the fuel pump plastic assembly in half...well...makes sense something broke or isn't working right.

Need to tig an aluminum pump frame, put in a Walbro with an external fuel filter, regulator and return line.

-Mac
 
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I just recently changed out my injectors. These are the factory injectors at about 95k miles on my 05. They were all still working as far as I know, but boy do they look toasty.

Does DEI make a kit for the 05-06? Their site only shows 97-04 but I'm not sure what the difference would really be

PXL_20230830_200452645(1).jpg
 
I installed a DEI kit when I replaced my injectors, #3 was bad on my 05 Kit came with lower shield, injector shields and fuel rail shield. I nought the shield and 4 hole injectors from K Suspension.
 
macleanflood said:
Protect from heat...the rail and the injectors.
...

-Mac
Click to expand...

bluescapegoat said:
I just recently changed out my injectors. These are the factory injectors at about 95k miles on my 05. They were all still working as far as I know, but boy do they look toasty.

Does DEI make a kit for the 05-06? Their site only shows 97-04 but I'm not sure what the difference would really be
Click to expand...

bucky said:
I installed a DEI kit when I replaced my injectors, #3 was bad on my 05 Kit came with lower shield, injector shields and fuel rail shield. I nought the shield and 4 hole injectors from K Suspension.
Click to expand...

Looks like this is for the 4.0, whereas mine is the 2.5. I so might just make do with some tape like the one linked above.
 
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SSTJ said:
Looks like this is for the 4.0, whereas mine is the 2.5. I so might just make do with some tape like the one linked above.
Click to expand...

I was interested in the shield in particular since mine is crumbling pretty good but I see you can still get a mopar shield for the 02-06 4.0 for $27.

Tesa tape, as far as I know, is just a more heat tolerant, nicer looking electrical tape. I always keep a couple rolls of it for wrapping wire looms, although in my experience thanks to it's fuzzy backing it can come undone if exposed directly to a lot of water/dirt like the evap or tail light wiring can in the back of the tub, so you have to be kind of clever about how you wrap it.

I wouldn't expect it to do anything for heat, but perhaps retain it. You can get adhesive heat-reflecting tape though (for the fuel rail.) Lots of options on amazon and DEI makes some themselves. I don't know if it works better than their velcro kits, but tautly wrapped heat shield tape certainly looks more finished, imo. Also a pain to remove if you need to.

::edit::
It also looks like the DEI kit fits the 05-06 just fine, you need to cut a hole for the diaphragm or whatever you call that jobbie on the fuel rail and maybe a couple other spots. I might just buy the kit.
 
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