Voltage problems after TPI swap. - Team Camaro Tech
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post #1 of 4 (permalink) Old Apr 4th, 09, 08:27 AM Thread Starter
Join Date: Dec 2008
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Voltage problems after TPI swap.

Hi there...I am pretty new to this forum so I didn't know where to put this post but I think I may be right. Anyway my car is a 1987 Camaro.

The stock engine in the was was a LG4 engine...That means 305 computer controlled quadrajet carb engine.

I have always been so excited about those TPI engines. I don't know why I just am. And after a while I wanted to convert my carbed engine to TPI.

The swap went pretty good but know I have some problems with the voltage on the car.

I have a 60A battery that have been factory tested yesterday and it should be good they said. My alternator is also providing power because when I measure the voltage when the engine is running I have about 14.2volts...Varying a little bit..

When engine is off the battery shows about 12.3 to 12.5volts..

My main problem is the ECM and the voltmeter inside the car at the gauges. The voltmeter is reading about 10volts and jumps up and down all the time..2seconds with 13volt and suddenly 3 seconds with 9volts and if I put on the lights i can drop down to 7 and 8 volts on that voltmeter and the idle of the car is getting terrible...after a couple of seconds the volts jumps up to 13 volt again and the car idles fine...

Any ideas of what this could be???...
I have been measuring the voltage around several places in the engine bay. Between battery and alternator...at the inline fuse that goes to ECM...and several other cables and it is reading about 14 when engine running and same as battery when engine is off...
Please give me some hints here..I need every information I can get.
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post #2 of 4 (permalink) Old Apr 4th, 09, 01:44 PM
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Location: PGH. PA
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Re: Voltage problems after TPI swap.

probably bad body ground
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post #3 of 4 (permalink) Old Apr 4th, 09, 09:45 PM Thread Starter
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Re: Voltage problems after TPI swap.

Originally Posted by stellar View Post
probably bad body ground
No I don't think so because I have checked all of the ground's.
There are one TAN cable that goes out of the wiring harness behind the engine and one white and to blk/white wires. They go to each side of the cylinder heads behind the engine...They are tighten up good and have good ground. I have also measured them with a voltmeter..

I know of the starter motor. On the starter solenoid where you connect the to main wires for the TPI wiring harness...They are not tighten any good because the threads on the starter solenoid is broken...The nut on will only turn around and around...But i don't think this would affect anything.
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post #4 of 4 (permalink) Old Apr 4th, 09, 09:49 PM Thread Starter
Join Date: Dec 2008
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Re: Voltage problems after TPI swap.

Here is a link to a movie clip of my idling...
My english is not good but you can see the voltmeter how it acts on several situations.

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