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TPS AND FAST IDLE


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Hi guys,

 

88 MJ, 4.0, Ba-10, C101 bypassed

 

I've been having trouble with the truck occassionaly going to 3000 rpm and staying there, usually i have to unplug and replug the IAC to correct it.   I decided to try a new TPS to see if it made any difference.  

In the course of doing Cruiser's TPS adjust, i found I only have 4.32V on the 5V supply line.  I removed the computer to check continuity on the 5V supply line at pin C15, and found i only had 1 ohm of resistance.  I noticed that the line  to the TPS was light blue at the computer, but was blue with a tracer at the TPS so i'm thinking there is a splice somewhere in the line that is intermittent.

 

My questions: 

Is the low supply voltage a cause for concern?

Does anyone know a better way or place to remount the computer?

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Had suspicions about my meter, so i went out this morning and tried again.  Turns out my meter was joshing me....all is well now.

I had 4.82V on the supply line.  I set the output to .79v which is a little lower than 17% but my idle has smoothed out at around 750 rpm, never been that low.....

Which brings up another question, instead of setting the voltage at 17% of supply, could you not just start the engine and rotate the TPS to get the desired idle RPM?

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Hi guys,

 

88 MJ, 4.0, Ba-10, C101 bypassed

 

I've been having trouble with the truck occassionaly going to 3000 rpm and staying there, usually i have to unplug and replug the IAC to correct it.   I decided to try a new TPS to see if it made any difference.  

In the course of doing Cruiser's TPS adjust, i found I only have 4.32V on the 5V supply line.  I removed the computer to check continuity on the 5V supply line at pin C15, and found i only had 1 ohm of resistance.  I noticed that the line  to the TPS was light blue at the computer, but was blue with a tracer at the TPS so i'm thinking there is a splice somewhere in the line that is intermittent.

 

My questions: 

Is the low supply voltage a cause for concern?

Does anyone know a better way or place to remount the computer?

 

 

Good observation/thinking on your part.  :thumbsup:    It will be a bish to track down, but that is probably going to be your best bet.

 

Our wiring looms are notorious for having piss poor splices from the factory.  :shake:

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