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Noisy fuel injectors
Posted: March 15th, 2011, 6:29 pm
by NoisyTJ
Hey everybody, havent been on here since I finished my stroker build, been having too much fun driving and wheeling it! The Jeep runs awesome but my biggest complaing is the noise from my fuel injectors. They are E-Bay parts from a 2003 or 2004 Mustang Cobra. I dont have any issues with driveability or detonation or anything like that, I'm just tired of listening to them tick away under the hood. Has anyone done anything like insulating the injector or fuel rail to cut down on the noise?
Re: Noisy fuel injectors
Posted: March 15th, 2011, 6:41 pm
by IH 392
Turn the radio up and/or your exhaust isn't loud enough.
Re: Noisy fuel injectors
Posted: March 15th, 2011, 7:35 pm
by SilverXJ
How do you know it the injectors? What cam are you running?
Re: Noisy fuel injectors
Posted: March 15th, 2011, 9:37 pm
by gradon
Sometimes you have to compromise for performance upgrades--noise tends to be one of the first compromises, along with fuel economy

Re: Noisy fuel injectors
Posted: March 15th, 2011, 11:26 pm
by BDD
SilverXJ wrote:How do you know it the injectors? What cam are you running?
X2 a lot of comp cams close the valve so fast they are really noisy.i've always had good luck with them but they are noisy.
Re: Noisy fuel injectors
Posted: March 16th, 2011, 6:48 am
by SilverXJ
That is what I am getting at. Both the 68-231 and 68-232 I have used have been noisy. It sounds like a ticking or even a small exhaust leak, but its just the valve train. I have also used those injectors (too large though) and they never made a sound, both new and a cleaned used set.
Re: Noisy fuel injectors
Posted: March 16th, 2011, 11:58 am
by Cheromaniac
gradon wrote:Sometimes you have to compromise for performance upgrades--noise tends to be one of the first compromises, along with fuel economy

I'm getting better fuel economy with my stroker than I was from my old healthy 4.0 so the extra performance doesn't have to come with a penalty.

Re: Noisy fuel injectors
Posted: March 16th, 2011, 12:53 pm
by montelibre
I have had three types of injectors in my Jeep and the noise made is very low, almost negligible. I´ve never heard a very loud engine with the injectors.
Re: Noisy fuel injectors
Posted: March 16th, 2011, 5:59 pm
by NoisyTJ
This is my second 68-232. The first one ate the lifters and most of the lobes during break in.
I guess it could just be the valves closing but after the first cam I dont want to hear anything valvetrain related so I was hoping it was the injectors.
btw, my exhaust is plenty loud

Re: Noisy fuel injectors
Posted: March 16th, 2011, 7:08 pm
by SilverXJ
Wow.. thats odd. Did comp have any explanation when you sent it back?
Don't worry about the sound though. Its normal for the Comp XE cams to be noisy. I chased what I thought was an exhaust leak for a long time.. it was the cam.
Re: Noisy fuel injectors
Posted: March 16th, 2011, 7:38 pm
by 97_xj
Hey, I had a piston skirt break off on my 97 cherokee on #2 cylinder. So I'm having it rebuilt to a "poormans stroker" (4.2 crank and rods with 4.0 pistons and stock cam. To be a 4.6L). Because I am on a tight budget. I am wondering if I could get away with using the stock fuel injectors without any problems on 87 oct. pump gas or 91oct. pump gas or if I would be better off buying different ones. And if so, what kind and output do you recommend. I have heard of this being a problem but I'm not sure if that is only on the larger stroker kits. Any help is greatly appreciated. I should get the engine back from the machinist in about a week or so. It is my daily driver and would like to have everything ready to install as soon as he is done. Thank you
Re: Noisy fuel injectors
Posted: March 17th, 2011, 6:46 pm
by NoisyTJ
SilverXJ wrote:Wow.. thats odd. Did comp have any explanation when you sent it back?
Don't worry about the sound though. Its normal for the Comp XE cams to be noisy. I chased what I thought was an exhaust leak for a long time.. it was the cam.
I couldn't get Comp to tell me anything. They warrantied the cam and lifters, but not all the parts and machine work that had to be done a second time because of the shavings getting pumped throughout the engine. I used the same oil and zinc additive that my machinist does and broke it in with the Comp instructions.
I'm not too worried about it. It's been running since last April with zero problems so I guess I can live with the noise.