7.3 problem! Need help
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Joined: Mar 2014
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7.3 problem! Need help
Just bought a 99 7.3 with 278k on the chassis and 25k on engine and tranny. Its got 150 horse injectors, bigger turbo(not quite sure Wat size), ts 6 position runner custom to injectors and turbo, and supposedly the engine is completely built. It was dunk'd last month at 740 hp. I was driving last week and noticed almost a backfire nice coming through the intake. I can also hear something, possibly a rocker arm, just barley tapping the valve cover. The boost gaugeflickers now too almost alike an intake valve is staying open while in the compression stroke and pushing air back through the turbo and intake. I am thinking possibly broken valve spring?? Or maybe a push rod or rocker arm? What do you guys think?
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
No way to know until you pop the top. You'll need to pull the Valve covers off and see what's visible. I'd stop driving it, though.
740 HP is scary... are you sure that's not 740 ft-lbs of torque? I've heard AC 160/100s called "140 HP" injectors, but nothing short of 450/400s will dump that much HP... and that ain't a "150 HP" stick.
Oh... and a jacked-up 7.3L with 280K needs a little more care than lashing on the testostopedal all the time because it's fun. I hope you aren't one of those who seeks out high-revving races on a frequent basis.
740 HP is scary... are you sure that's not 740 ft-lbs of torque? I've heard AC 160/100s called "140 HP" injectors, but nothing short of 450/400s will dump that much HP... and that ain't a "150 HP" stick.
Oh... and a jacked-up 7.3L with 280K needs a little more care than lashing on the testostopedal all the time because it's fun. I hope you aren't one of those who seeks out high-revving races on a frequent basis.
Fleet Mechanic
Joined: Apr 2011
Posts: 1,441
Likes: 6
From: Marseilles IL
It sounds like it may have a bent pushrod or a broken rocker arm. I hope you don't plan on driving that truck as a daily driver, it's gonna be expensive. I drive my truck daily to work and I'm only at 400+ hp and that's pushing it, in my opinion, for a reliable long lasting daily driver. As your finding out now, keeping that much horsepower going is a constant job. At 700+ hp everything is being pushed to near its limits every time you turn the key! And FYI if you dynoed 740 hp you definatly do not have 150 horse injectors! As said above you are going to have to pull the valve covers and see what's going on. Good luck.
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To tell ya the truth, the 150 horse injectors was just kind of an estimate. We bought it from a guy in Montana and he said it had that much hp so I kinda took a guess on the injectors. We had it dynoed ourselves from a friend who has a race shop and it was like 743.4 hp
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Lead Driver
Joined: Jun 2007
Posts: 7,760
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From: Hampton, Maryland.
You need to take some pictures of your setup and post them up. If you don't already have one, start a photobucket or similar account, load up a bunch of pics then link to them from here.
Lead Driver
Joined: Jun 2007
Posts: 7,760
Likes: 27
From: Hampton, Maryland.
If you go to photobucket.com you can upload pictures to their site, either from your smartphone or by taking them with a camera and then uploading them to your computer then to photobucket. Then there or image codes for each picture that you can post or you can link to the whole album if you want.
Lead Driver
Joined: Jun 2007
Posts: 7,760
Likes: 27
From: Hampton, Maryland.
Once you get 25 posts here, they will activate your ability to post pics and then you can add pictures here on your user cp. they have 3 albums you can store here and then link to them as well.
