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High idle at cold start


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Just got back to the states again and the truck has been setting for the last 4 months. When I start it in the morning you never know what its gonna do, it will either rev up and down or just go straight to almost 1000 rpm. It went to 1000 this morning and I got about 2 minutes down the road and it started idleing normal. My alternator is charging at idle and I just ordered one of Goulds rebuilt kits so I hope this fixes both problems but I dont know.

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Something is a bit fishy... Take a ohm meter and check the IAT resistance against the table...[TABLE][TR][TD=width: 50%, bgcolor: #3870cc]Temperature[/TD][TD=width: 50%, bgcolor: #3870cc] Resistance[/TD][/TR][TR][TD=width: 50%] 13°F[/TD][TD=width: 50%] 56K ohms[/TD][/TR][TR][TD] 26°F[/TD][TD] 39K ohms[/TD][/TR][TR][TD=width: 50%] 87ºF[/TD][TD=width: 50%] 7.4K ohms[/TD][/TR][TR][TD=width: 50%] 91°F[/TD][TD=width: 50%] 6.8K ohms[/TD][/TR][TR][TD=width: 50%] 100°F[/TD][TD=width: 50%] 5.6k ohms[/TD][/TR][TR][TD=width: 50%] 107°F[/TD][TD=width: 50%] 4.7K ohms[/TD][/TR][TR][TD=width: 50%] 112°F[/TD][TD=width: 50%] 4.3K ohms[/TD][/TR][TR][TD=width: 50%] 119ºF[/TD][TD=width: 50%] 3.6K ohms[/TD][/TR][TR][TD=width: 50%] 123ºF[/TD][TD=width: 50%] 3.3K ohms[/TD][/TR][TR][TD=width: 50%] 127ºF[/TD][TD=width: 50%] 3.0K ohms[/TD][/TR][TR][TD=width: 50%] 132ºF[/TD][TD=width: 50%] 2.7k ohms[/TD][/TR][TR][TD] 143°F[/TD][TD] 2.2k ohms[/TD][/TR][TR][TD] 148°F[/TD][TD] 2.0k ohms[/TD][/TR][TR][TD] 163°F[/TD][TD] 1.5k ohms[/TD][/TR][TR][TD] 173°F[/TD][TD] 1.2k ohms[/TD][/TR][TR][TD] 184°F[/TD][TD] 1.0k ohms[/TD][/TR][/TABLE]

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I didnt check the ohms but but it cranked up and idled fine today. I messed with the iat plug a little but dont know if it changed anything. I did use the high idle today and it worked but at soon as I turned it on it went to 1300rpm, then I turned it off and it went off. I then turned it back on and it didnt do anything but when I turned the switch off it idled up. Its fishy but I did get my new brushes in my alternator and havent tried the high idle. My alternator is charging at idle now too.

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  • 2 weeks later...
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I didnt check the ohms but but it cranked up and idled fine today. I messed with the iat plug a little but dont know if it changed anything. I did use the high idle today and it worked but at soon as I turned it on it went to 1300rpm, then I turned it off and it went off. I then turned it back on and it didnt do anything but when I turned the switch off it idled up. Its fishy but I did get my new brushes in my alternator and havent tried the high idle. My alternator is charging at idle now too.

Ok... Try this...

http://mopar.mopar1973man.com/cummins/2ndgen24v/high-idle-diag/high-idle-diagnostics.htm

i am having troubles with iat.....new sensor installed...and cel comes on 0113 code shows up..erase it with...comes right back.....

Here you go...

P0113 - Intake Air Temp Sensor Voltage High

Intake air (charge) temperature sensor input above the maximum acceptable voltage.

Monitor & Set Conditions

Intake Air Temperature (IAT) sensor voltage is monitored when ignition is on and battery voltage is greater

than 10.4 volts. DTC may be stored when IAT sensor voltage at ECM is greater than 4.97 volts for greater than

2 seconds.

Possible Causes

[*] Intermittent Wiring Problem

[*] IAT Signal Circuit Shorted To Voltage

[*] IAT Sensor Signal Circuit Open

[*] Sensor Ground Circuit Open

[*] IAT Sensor

[*] ECM

Testing

1. Turn ignition on with engine off. Using DRBIII® scan tool, read IAT sensor voltage. If IAT sensor

voltage is greater than 4.5 volts, go to next step. If IAT sensor voltage is 4.5 volts or less, go to step 6 .

2. Turn ignition off. Disconnect IAT sensor harness connector. IAT sensor is located on driver's side rear

corner of cylinder head. Turn ignition on with engine off. Using scan tool, read IAT sensor voltage. If

IAT sensor voltage is 6 volts or less, go to next step. If IAT sensor voltage is greater than 6 volts, repair

IAT sensor signal circuit for a short to voltage.

3. Turn ignition off. Connect a fused jumper wire between IAT sensor harness connector terminals. Turn

ignition on with engine off. Turn ignition on with engine off. Using scan tool, read IAT sensor voltage. If

IAT sensor voltage is one volt or greater, go to next step. If IAT sensor voltage is less than one volt,

replace IAT sensor. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.

4. Turn ignition off. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in

front of fuel transfer pump and contains a 50-pin connector. Ensure IAT sensor harness connector is still

disconnected. Using DVOM, measure resistance of Black/Red wire between terminal "B" on IAT sensor

connector and terminal No. 7 on ECM connector. If resistance is less than 10 ohms, go to next step. If

resistance is 10 ohms or greater, repair open in Black/Red wire between IAT sensor and ECM.

5. Using DVOM, measure resistance between ground and IAT sensor harness connector terminal

"A" (Black/Light Blue wire). If resistance is less than 10 ohms, replace and program the ECM. See

appropriate REMOVAL, OVERHAUL & INSTALLATION article. If resistance is 10 ohms or greater,

repair open in IAT sensor ground circuit.

6. The conditions that set the DTC are not present at this time. With ignition on engine off, monitor DRBIII

® scan tool parameters related to the DTC while wiggling wiring harness. Look for parameter values to

change and/or a DTC to set. Review the DRBIII® Freeze Frame information. If possible, try to

duplicate the conditions under which the DTC was set. Refer to any Technical Service Bulletins (TSB)

that may apply. Visually inspect the related wire harness. Look for any chafed, pierced, pinched or

partially broken wires. Visually inspect the related wire harness connectors. Look for broken, bent,

pushed out or corroded terminals. Were any of the above conditions present? If yes, repair as necessary. If

no, test is complete.

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