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ryan
Dodge Dakota
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3/15/2007
00:56:08
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 Subject: 4.7 barely starts
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Message:
my 3.9 is running great but my friend's 2002 4.7 seems to be having some problems. he just got the truck like a month ago and it was fine until a few days ago. first of all today we rode around in it and i noticed it sounded like the power steering pump was really struggling so i looked at it and sure enough it was really low on fluid. we filled it up and that fixed that problem. the other thing is, about half the time the truck BARELY starts. it'll crank over for like 10 seconds and finally fire and acts like its gonna die until you give it some gas. and i guess he told me that sometimes if he just puts it in park or something it'll stall. it seems to me like it's not getting any gas on start up or at low rpm's. once it does start up though it normally runs fine. and another thing, the oil pressure seems to be really low. the needle on the guage usually sits right on the first line or a little below. the dipstick reads right in the middle of the safe and it looks like it just had an oil change right before he bought it. could all this be related? the power steering pump leak? the low oil pressure? like i said, i keep my 3.9 running great and i know that motor inside and out but this 4.7 is foreign to me. so a little help would be greatly appreciated.
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Kowalski
GenIII
3/15/2007
05:36:39
| RE: 4.7 barely starts
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Message:
I'd look for where the power steering fluid went. Some have reported a failure of the power steering pressure switch, leaking fluid into the wiring harness, and fowling an O2 sensor.
Lead, follow, or get out of the way
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01Motorsport
Dodge Dakota
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3/15/2007
07:38:04
| RE: 4.7 barely starts
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Message:
ryan, if your friend's 4.7 has the original spark plugs, or the throttle body needs cleaning, these could lead to starting problems. A dirty TB really affects the 4.7's driveability. There's always the possibility of water in the gas, either from a station, or always running on 1/2 full tank or less (condensation). Try a gas dryer/ injector cleaner.
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RaZoR1
Dodge Dakota
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3/19/2007
18:11:43
| RE: 4.7 barely starts
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Message:
COuld also be your fuel pump starting to go.
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GraphiteDak
GenIII
3/19/2007
22:45:42
| RE: 4.7 barely starts
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This is the second post in a week where I have read about the power steering pressure switch leaking and it can allow fluid to run down the harness and into the O2 sensor causing it to not run properly.
Check your O2 sensor's for fluid at the harness.
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ryan
Dodge Dakota
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3/19/2007
23:01:13
| RE: 4.7 barely starts
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GraphiteDak- that's what im thinking. I guess its only an intermittent problem, but when the weather warms up in ohio me and my friend are completely tuning up both our trucks and I'll definately look at that o2 sensor.
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OBIO3
Dodge Dakota
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3/19/2007
23:06:24
| RE: 4.7 barely starts
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Message:
I would be very worried about the low oil pressure. There has been several that the oil pickup screen plugs off. But as long as it seems to have had this problem, I'd say it most likely is the oil pressure gauge. But you just can't afford to take the chance. Engines are very pricey. Install a mechanical gauge where the sending unit is and see if this brings oil pressure up. If so, replace the sending unit. If not you can start worrying.
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JerryM
Dodge Dakota
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3/21/2007
16:12:29
| RE: 4.7 barely starts
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Message:
Kowalski is right, it happened to me a few years ago.
The PS pressure switch blows, leaks fluid into the wiring harness and to the drivers side pre-cat o2 sensor and fouls it.
Pull the power steering line pressure switch connector off and check for fluid.
I replaced the switch and o2 sensor and cleaned up the harness and wires with some good electrical contact cleaner.
No problem since then.
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