Cam
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ROTM Coordinator
ROTM Coordinator
Joined: Apr 2009
Posts: 1,828
Likes: 2
From: Orange County, CA
Just put it in the closed position and cap the line, if it runs great( sometimes real peppy) then its bad. It has a diaphram in it thats can eventually get stuck. it opens as necessary to recirclate unburned fuel & exaust.
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Professional Mechanic
Professional Mechanic
Joined: Nov 2008
Posts: 2,950
Likes: 5
From: Bowie, MD
You tested it exactly right. When the valve is open the truck should barely run or stall. The valve should be capable of holding the vac. If it functions like this it can not be bad. The next year up electronic valve can not be tested with a pump.
Thread Starter
Super Moderator
Joined: Mar 2009
Posts: 1,635
Likes: 2
From: Michigan
MMk Guys thanks for your awnsers!! Is there a way to diagnose the ECM?
Mudmaniac: Why did you replace your computer? What was it doing? Oh and I just put a new Hypertech chip in it today is there a way to get these set to yourlikings? And If I do some testing and feel it needs a new ECM I can get one new for 100 dollars and I will put my old prom chip in it!
Thanks guys!!
Mudmaniac: Why did you replace your computer? What was it doing? Oh and I just put a new Hypertech chip in it today is there a way to get these set to yourlikings? And If I do some testing and feel it needs a new ECM I can get one new for 100 dollars and I will put my old prom chip in it!
Thanks guys!!
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Ride of the Month
May 2009
Ride of the Month
May 2009
Joined: Jan 2008
Posts: 1,598
Likes: 1
From: Westminster, Md.
I was having similar problems after changing my intake and throttle body, anyhow for some reason I was convinced the ECM was my problem. It wasn't, my injectors were to large after changing the intake and it was running way to rich.
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Joined: Apr 2008
Posts: 7,573
Likes: 47
From: Austin, Texas
Can engine computers go bad??? Is there a way to test it? When you replace a computer can you just plug it in and go? I just wondering because My truck is running like crap and ive replaced every sensor(trust me every sensor) Ran compression test, fuel pressure test, Took it to the dealer, and 2 other mechanics. And when I put the 350 in to replace the 305(40,000) miles ago I did not replace the the computer, just the prom chip and it ran fine untill now. ANy help is appreciated