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Old 09-26-2012, 10:03 AM   #1
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So I changed my cam syncro and it ran awesome work a week and a half, then lastnight on the way home it burned a quarter tank of gas in twenty to thirty miles, and won't go over 50mph and bad sputter and today it is worse.... Doesn't want to go over thirty and is running really ruff.

No codes yet, the only things I haven't changed trying to fix this problem is the fuel injectors.... I did pressure test the fuel rail it is getting 16-17psi which is about right for the fuel pump to push...

Does anyone have any idea what the hell is going on?!?!?!?! Has anyone had the same symptoms this is getting really old!!!!!

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Old 09-26-2012, 10:32 AM   #2
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Someone anyone???? I would love some help with this plz...

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Old 09-26-2012, 01:07 PM   #3
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16-17 psi is enough for an older carbureted engine but the TJ's fuel rail pressure is supposed to be 49 psi. Sounds like your fuel pump is bad if there is no leak anywhere in the fuel system.
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Old 09-26-2012, 05:06 PM   #4
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fuel pump is my guess with it reading no codes.
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Old 09-26-2012, 05:46 PM   #5
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It runs better the more gas it has????
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Old 09-26-2012, 05:51 PM   #6
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not more gas so much as more pressure behind it. keep in mind if your engine is spinning at 1000 rpm that each cylinder fires 250 times in that minute. thats more than 4 times every second. in order for each injector to easily provide enough fuel to do that everytime you need a lot more pressure than an old mechanical system whose fuel pump only had to feed one jet maybe 2 doing the same thing.
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Old 09-26-2012, 06:04 PM   #7
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Quote:
Originally Posted by ken78744 View Post
It runs better the more gas it has????
Your present fuel pressure is only 1/3 of what it should be, the injectors won't spray correctly and your engine isn't getting the fuel volume it should. Replace the fuel pump.

Again, your TJ's fuel pressure is only 16-17 psi but it is supposed to be 49 psi. To me, that'd be a no-brainer it's time to replace the fuel pump.
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Old 09-26-2012, 06:45 PM   #8
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Getting a new pump Friday for $108.99 from work doing the swap Friday.... Hope this fixes it....
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Old 09-26-2012, 06:59 PM   #9
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There may be other issues but the new fuel pump will get the fuel rail pressure up to where it should be.

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