Jayking

Hi Everyone,

My father and I built a street rod with a chevy 350. We added a TPI system off a 86' Camaro. It turned out really beautiful and worked nicely for about a year, but ow I have been plagued with issues.

Now the truck starts and runs beautifully, but I can only drive around 15 minutes or so (sometimes less/more) before the system starts drawing a lot of current and I can see the battery voltage drop until the car literally shuts off. I have tried replacing the alternator, and pulling all the fuses that are non essential to the truck running and driving.

I am not sure if it is an issue with something getting over loaded or hot, but it seems to "reset" after letting the car sit for an hour or so.

Any tips to help me track down the issue or suggestions on what it might be would be appreciated.

-Jay

TTOP350

iTrader: (8)

That's really odd. This will sound more odd, Fuel psi check when system is failing? how is the tank being vented? did that fail? What type of cooling fan are you running? electric?

bigal55

iTrader: (1)

I would look at the starter, it's about the only thing capable of drawing that much power to drain the battery like that, unless of course, the battery is bad itself. HTH!

Jayking

Hi TTOP,

I have not checked the Fuel psi. My street rod is running on a 1985 Chevy S-10, the tank on the S10 has been dropped and treated during the restoration, the venting is stock. What are you thinking in regards to fuel pressure causing this issue?

I am running and electric fan, to save some space.

BigAl,

I have tried replacing the battery as well (borrowing one). I can try testing the starter circuit once the short starts.

TTOP350

iTrader: (8)

I'm thinking that if there is a serious vac issue in the fuel tank the pump may be pulling extra amps to try to move fuel until the vac gets to be to much and just kills it for lack of volts and fuel psi.. very long shot or maybe even the fuel filter is plugged?
Electric fan spins easy by hand?
I wouldn't think a starter would draw power unless its spinning.

Throwing lots of baloney at the wall, maybe something will stick

Jayking

I don't believe it is a fuel issue, the engine never has any performance issue. I will be driving along with 14.4V with the engine running and then it is like a switch is flipped and I can watch the voltage drop down to ~10V and slowly drop from there. Even as the voltage is dropping the engine runs fine until the whole system shuts off due to lack of electricity. I can drive for a good 10 minutes after the "short" is tripped.

I have tried pulling the fan fuse but no luck.

-Jay

bigal55

iTrader: (1)

Do you have to be driving the car in order for this to happen or if it idles for 15 minutes will it draw down the voltage and die? Reason I ask is, as the voltage starts to drop, you have about 10 minutes to do some testing before it dies. If you let the car sit to cool, it will restart fine but will it crank after it dies or does it act like the battery is dead. When the voltage starts to drop, what is the voltage at the alternator? Thinking you may not have a current draw but a voltage loss due to a bad connection somewhere. Ground wire connection getting hot and building resistance or possibly a bad positive connection at the starter or alternator. Get out the voltmeter and start checking voltages. Check your alternator output as suggested above and even across the battery terminals to see if the battery voltage follows the volt gauge reading. Check your fusible links at the starter connection and the alternator. HTH!

Jayking

Hi BigAl,

It can just be idling to start the short, does not require it to drive.

The battery voltage is actually draining, if I shut the truck off right when the short occurs it will restart fine, but still have the current draw. If I drive it until dead the battery is actually dead and has to be recharged. The truck must cool for the short to "reset".

The alternator is always putting out 14.4 volts even when the battery is draining

I'll try to check this weekend, work is really busy right now, I have not check the connections down through the starter circuit. I will also pull all my grounds and clean them if necessary, maybe put some conductive grease on them as well.

Thanks for the comments.

Richard woody

Not sure what distributor you have.but I would have ignition control module checked .auto zone can check it free..

OrangeBird

iTrader: (1)

Bad advice ......

There is no way , no how , in any failure mode possible , that the ICM could fail in such a way to cause Jay's truck's symptoms . He describes his voltage dropping like a rock till the battery has been literally sucked dry of voltage , and there is no way possible for the ICM to draw the kind of current required to do that . This is a big wire or big current item at fault here , and not an ICM that would vaporize at an honest 25 Amps of full time current draw .

Don't forget , causes gotta match ALL the symptoms , and just because a failing ICM commonly will run 10 to 15 minutes and then make the engine quit , it NEVER takes out every volt outta the battery when it does so !