Bosch 4 hole injectors
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Junior Member
Joined: Dec 2015
Posts: 63
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From: Dutchess county NY
Year: 2004
Model: Grand Cherokee
Engine: 4.7
2004 GJ 4.7...any reason why I shouldn't use these injectors??? I Have been chasing a misfire code and removed injectors to clean and noticed that 2 were cracked and 1 was a different injector. 7 were 2 hole injectors with a red stripe and 1 was a 4 hole injector with a green stripe!!!! I found Bosch 3rd Gen 4 hole upgrade injectors online for $151.95 from Precision Auto Injectors. I know 1 stock injector at my local autoparts store is about $45...so $150 for 8 sounds pretty good to me. Any thoughts would be appreciated!!!!!
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
I bought a set of the same injectors from the same company for my 4.0 and they're working perfectly. 2 of my original Seimens injectors were cracked as well. Just remember they are remans; cleaned, flow tested, coil tested, and spray pattern tested. Flow rate really doesn't matter much because the PCM controls mixture by regulating "on-time." Smaller fuel droplets created by the 4-holers make the idle smoother and the off-idle response quicker. I found the tires would slip coming off a stop when going over the white painted stop lines until I learned to softpedal it a little.
Last edited by dave1123; Nov 23, 2017 at 04:16 PM.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
On 4.0s, it's heat from the exhaust. It's probably just cheap plastic anyway. There's just a thin layer over the magnet coils.
CF Veteran




Joined: May 2012
Posts: 7,965
Likes: 964
From: Lost in the wilds of Virginia
Year: 1998 Classic (I'll get it running soon....) and 02 Grand
Model: Cherokee (XJ)
Engine: 4.0
Tests have been done that show there is very little gain to be had in going more than 4 hole. There's a good vid on YouTube that shows them side by side. 1 hole to 4 hole is a big difference. 4 hole to 8 or 12? A very slight difference. I would not waste my money or time looking for 12 hole.
I know, I know, more is always better, right? (That's why people do dumb things like using 00 welding cable for their starter. It does nothing useful, but it's bragging rights.)
No, it's not. Sometimes it's worse. Sometimes it's slightly better but not enough to make it worth the effort and cost. This is one of those times.
As for the 62mm, if you are not also doing some exhaust work you are probably wasting your time and money.
Here's the stock vs. 4 hole video, from the company mentioned above.
Here's 4 vs. 12. You can see there's not much to get excited about.
I know, I know, more is always better, right? (That's why people do dumb things like using 00 welding cable for their starter. It does nothing useful, but it's bragging rights.)
No, it's not. Sometimes it's worse. Sometimes it's slightly better but not enough to make it worth the effort and cost. This is one of those times.
As for the 62mm, if you are not also doing some exhaust work you are probably wasting your time and money.
Here's the stock vs. 4 hole video, from the company mentioned above.
Here's 4 vs. 12. You can see there's not much to get excited about.


