| Author |
Message |
    
ron beckson
New member
Username: ronbeckson
Post Number: 1
Registered: 07-2006
| | Posted on Friday, January 22, 2010 - 12:29 pm: | 
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I have 454 Horizon,the rpms go up and down between 1000 & 1300 in a looping action,under 1000& over 1300 are fine.Anyone know whats wrong? |
Boat Tech
Member
Username: boat_tech
Post Number: 26
Registered: 01-2010
| | Posted on Friday, January 22, 2010 - 01:15 pm: |
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Dose this do this at idle or just off idle??? |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 5542
Registered: 08-2006
| | Posted on Friday, January 22, 2010 - 01:16 pm: |
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What year? MPI? Maybe might be computer temp. sender or IAC motor gummed up. |
ron beckson
New member
Username: ronbeckson
Post Number: 2
Registered: 07-2006
| | Posted on Saturday, January 23, 2010 - 08:47 am: |
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Boat Tech -- Just off idle |
ron beckson
New member
Username: ronbeckson
Post Number: 3
Registered: 07-2006
| | Posted on Saturday, January 23, 2010 - 08:50 am: |
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Guy -- 1999 horizon cross ram MPI |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 5543
Registered: 08-2006
| | Posted on Saturday, January 23, 2010 - 09:39 am: |
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The coolant temp. sensor is on the T'stat hsg. The hsg. gasket has two small continuity buttons in it to complete the eletrical circuit ground. If it is corroded that could be part of the problem. Does the temp gauge read correctly all the time?
Cleaning the throttle body (TB) bore and thottle plate will improve idle. Use THROTTLE BODY CLEANER and not carb cleaner. Check all the electrial connections on the TB. |
ron beckson
Member
Username: ronbeckson
Post Number: 4
Registered: 07-2006
| | Posted on Saturday, January 23, 2010 - 03:49 pm: |
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Guy -- temp guage reads correctly all the time. |
Guy Gaspar
Senior Member
Username: guyjg
Post Number: 5544
Registered: 08-2006
| | Posted on Saturday, January 23, 2010 - 10:43 pm: |
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Try cleaning the TB. Test the TPS (Throttle Position Sensor) w/a digital VM for a dead spot. |
