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  #1  
Old 11-09-2014, 06:43 PM
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2000 Grand Cherokee W/weak acceleration

Just purchased 2000 grand cherokee with v6 the truck takes forever to pick up speed. If I put the pedal to the floor I may get 2500 Rpm. I've checked and cleaned plugs, cleaned throttle body, checked air filter, tryed using 1 and 2 gears, and released fuel from fuel rail seems to be plenty of pressure. Someone please give me a brilliant idea I would like to get this jeep on the road

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  #2  
Old 11-09-2014, 07:09 PM
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Re: 2000 Grand Cherokee W/weak acceleration

The major factor for the fuel injection pulse is the MAP signal. If you have a scanner which shows live data, then you could check the MAP with ignition in run, engine off, and compare it with the local atmospheric pressure. When way of, then its time for a new MAP sensor.
An other thing could be a clogged exhaust (silencer or catalyser)
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Old 11-09-2014, 07:23 PM
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Quote:
Originally Posted by Frango100 View Post
The major factor for the fuel injection pulse is the MAP signal. If you have a scanner which shows live data, then you could check the MAP with ignition in run, engine off, and compare it with the local atmospheric pressure. When way of, then its time for a new MAP sensor.
An other thing could be a clogged exhaust (silencer or catalyser)
I will hook it up to the scanner and give it a try in the morning. How would I go about checking the exaust?
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Old 11-09-2014, 07:31 PM
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Re: 2000 Grand Cherokee W/weak acceleration

You could remove the exhaust and give it a try. It will ofcourse give a lot of noise and you have to be carefull that the hot gasses will not melt any wiring. I donīt know if an exhaust shop has a way to test the flow through the exhaust.
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Old 11-09-2014, 07:51 PM
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Ok frangoo I'll give both a try and post results. I've found a few ways to test exaust on Google.
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Old 11-10-2014, 02:18 PM
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Hey frango the map sensor is reading 28.3 off and been 10 and 15 while running
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Old 11-10-2014, 03:53 PM
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Re: 2000 Grand Cherokee W/weak acceleration

You will have to compare the ignition run/engine off figure with the local atmospheric pressure.
But as a comparrison, mine is 93 ignition run/engine off and 32 engine running. Yours seems to be quite low, but as told, you have to see if with the local atmospheric pressure. If you live high in the mountains, the pressure will be lower.
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Old 11-11-2014, 01:57 PM
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UPDATE today while messing around under the dash, i realized a great amount of slack was in the accelerator cable i used a vice to clamp the cable in place. On test drive i notice that it moves more snappy to the gas petal but boggs out at 2500rpm. When in park it boggs at 3000rpm
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Old 11-11-2014, 07:44 PM
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Re: 2000 Grand Cherokee W/weak acceleration

Since you found some slack in the accelerator cable, did you check if the throttle goes full open when the pedal is on the floor?
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Old 11-11-2014, 08:28 PM
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Yes the throttle is opening all the wayand looks very clean inside
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  #11  
Old 11-14-2014, 10:09 AM
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Re: 2000 Grand Cherokee W/weak acceleration

Just checked the MAP again today, but now with the Torque app (before i used my scanner) and it is still 93 off, but its measured in kPa. Your indication was most probably in inch Hg? Because the 93 kPa = 27.4 Inch Hg. My idle MAP will be then 9.4 inch Hg. Those figures are more in line with what you had given for your MAP and thus your MAP sensor seems to be working fine.
Did you check the exhaust for clogging?
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