kjc

A while back I upgraded the injectors in my '93 GC 4.0 with some 4 hole injectors out of a... (for the life of me, I can't recall) Dodge Neon? maybe? I dunno, but they made a marked improvement in performance.
Now I have another Jeep, an '05 grand cherokee laredo with the 3.7L v6 ... Is there a similar upgrade for these stock injectors? Sorry, I can't remember the details. Thanks for any help!

kjc

dave1123

Google is your friend!

remanufactured genuine Bosch 12-HOLE injectors, $120/set, Dimar Motorsports, ebay.

kjc

Thank you Dave. What I was looking for here was more of an experience based, or a "yes we've done that, we used these injectors" type of thing. Still, thanks for letting me know about that new "google" thing

zacmac1003

What performance differences can i expect from the 4 hole to the 12 hole?

dave1123

All I can say is based on simple engineering. Using the same basic flow rates, 4-hole over single hole, they produce a much finer fuel droplet resulting the a cleaner, faster burn because at the same pressure, the velocity is higher. I can see the 12-hole producing a true fog, but being more susceptible to carbon fouling of the orifices. Carbon in the intake manifold comes from oil vapors from the CCV being heated by the exhaust. This is more prevalent in a straight engine like the 4.0. I don't imagine this happens too much in a V engine.

50.Cal

I am also looking to replace my injectors. I have a 94 GC with a 98 engine, I didn't do that. I'm not sure what injectors are in there now but I was looking to get some from a Dodge Neon. Does it matter the year? I searched and didn't find any answers for my year/model. Also, I saw some people saying that if you swap from a 1 hole to a 4 your computer will have issues?

dave1123

No computer issues involved, except for the change in mixture handled by the PCM and 02 sensors. The main difference is the fuel is atomized better for a quicker, cleaner burn. If the PCM detects less 02 in the exhaust, it will change the injector on-time to compensate. You should notice quicker, cleaner throttle response, but not a big change in mpg.

On my 2000 WJ 4.0, I went from single-hole Siemens to 4-hole Bosch and it idles smoother, responds quicker to throttle changes, and seems to have more power, but my mpg didn't change significantly.

Isaac Noel

I think the neon Injector swap is a great upgrade for any cherokee. Super easy install and I could see improvement in power and gas mileage. I did this swap because a few of my cylinders where misfiring and this fixed it immediately it runs and idles much better. I went for some referbished bosh injectors for cheap on eday and they're great. I would recommend them over the cheap no name ones off amazon.