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Problems Driving In Mtns

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Old Sep 23, 2009 | 09:04 AM
  #1  
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From: Denver, CO
Problems Driving In Mtns

I have an 85 Pickup, reman 22r w/ approx 25000, 5.29 gears, 35" tires and I live in Colorado. All of the great trails are in the mtns and I have been having problems when driving uphill at wide open throttle. For anyone who knows Colorado and I-70, the first incline at Morrison is where I start to have problems. The ride to there is fine, no issues, then as I start to lose speed I would downshift to 4th, sometimes 3rd, and it would seem like the carb chokes out or gets flooded. The gas is floored and the rpms are bouncing back and forth but I am getting no response. If I pump the gas pedal it would usually jump back to life and it wouldn't go over 45 after that. A few times I even had to pull over, turn it off and then when I started up again it was like nothing was wrong. As soon as I start going downhill it will act normal and even go 65.

From what I have read sounds like I should start with a replacement fuel filter. I have put some carb cleaner in the gas and used midgrade to see if that helped, nothing. Anything else you guys can think of?

Thanks for the help.
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Old Sep 23, 2009 | 09:25 AM
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When you say "the rpms are bouncing back and forth", are you talking about the tachometer needle jumping around? If so, might be an ignition problem as that is what the tachometer "reads".
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Old Sep 23, 2009 | 09:44 AM
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Yeah I did mean the rpm needle bounces. I know the truck does have a new ignition in it from the previous owner.
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Old Sep 23, 2009 | 06:13 PM
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My 3.0 does that and every time it has been the ignitor/coil - but mine is FI, yours could easily be good ole' fashioned vapor lock.

If you don't know when the fuel filter was replaced last, I would start there.
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Old Oct 16, 2009 | 09:22 PM
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I have replaced the fuel filter, plugs and wires, and now it does it to me around town on the smallest hills. I looked through the window on the front of the carb and noticed that there was hardly any gas in it at all. I could see the gas at a steady drip, but it was well below the level the Chilton manual suggests. Could this be a clogged jet or something else? Thanks again for the help.
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Old Oct 16, 2009 | 11:29 PM
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Sounds like you might need to rebuild the carb. I would test the fuel pressure first though in case it's the fuel pump slowly dying.
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Old Oct 16, 2009 | 11:46 PM
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Sounds like you have a carb to me

I see a propane conversion in your future.
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Old Oct 17, 2009 | 06:23 PM
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I seem to have inherited a few issues, but hopefully nothing I can't fix. I can only guess that the timing chain was changed when the po put in the rebuilt motor, so over a year at least. I just changed the plugs, plug wires and fuel filter the other night so I haven't been able to tell if it made a drastic improvement yet. The ignition coil looked new as well as the rotor so I would say they were changed with the engine swap.

I did just notice that the drivers side motor mount isn't broken, but it looks to have moved upwards about an inch. I will post a picture of it when I can, but could this play any part in the carb not getting the proper fuel levels?
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Old Oct 17, 2009 | 07:32 PM
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I am leaning more toward the air side of the equation.

I'm not familiar enough with your motor but have to suspect it is either a clogged air filter-(too easy) or the air MAF or MAS. Some type of sensor for the air mix.

I would not put too much stock into the factory tach bounce if the RPMs are clearly not changing it could just be the tach itself acting up. My 95 2nd Gen Runner did that enough that I ended up hooking up a Nordskog digital tach to keep a more accurate eye on the revs.

How does it run at highway speeds around town?
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Old Oct 18, 2009 | 03:45 PM
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I will look into the fuel pump and start there. Here is a picture of my drivers side motor mount. I know I need a new one so I was thinking about the Trail Gear mounts. Anyone have any other suggestions or any good/bad stories about a certain brand?
Attached Thumbnails Problems Driving In Mtns-alderson.jpg  
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Old Oct 23, 2009 | 09:02 AM
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I had a similar power loss problem when I first bought my 85 carbed 22r pick up. I drive at around 7000 ft as well. I opened the fuel tank and saw that the pick up screen was FILLLED with gunk, I cleaned it, went through about 4 fuel filters in the next few months, used Berryman's B-12 gas treatment every other tank, and it seemed to make it better. I drove 1200 miles to Chicago yesterday with no problems, staying at 80mph for a few hours through kansas. I would stick with the fuel system if your carb level stays low. I also rebuilt the carb, changed plugs/wires, bought a new fuel pump while trying to diagnose this. I say start at the source (the tank) and work your way up the line, not backwards like I did. Good luck
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