Mechanics

CHEVROLET TRUCK BATTERY PROBLEM

1990 Chevrolet Truck • 130,000 miles

My truck seems to never wanna start I the morning it acts like the batteries dead but the volts were 12.5 eventually it starts or it'll start right away with a jumpbox I checked the battery when it was running and the battery was charging at 14.2 then with my lights raido and heat on the battery stayed in the 13's ive reaplaced compute sending unit did tuneup along with fuel filter along with all sensors and I just did the fuel pressure regulator once it starts in the morning it runs grat all day also I thought it was draw so I put a battery disconnect switch on the battery and I turn it off everynight then back on in the morning please help thanks matt
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Matttyw20
December 17, 2012.




The starter motor cranks ok, correct? Have meter leads across the battery posts, have helper turn key to crank. How far does the voltage reading drop? Use a gage and check fuel pressure. I didn't see litre size of engine listed? Any applicable mil codes?

If you have throttle body injection, the fuel pressure spec is around 10 psi. If you have multiport fuel injection, the pressure is higher, around 30 or 40 psi, I'd have to look up the exact spec.

JDL
Dec 17, 2012.
Yes the starter motor cranks good my mechanic put in a new send unit a while back as well so I'm pretty sure fuel pressures ok I'll have to check that tomorrow morning cause if I go out now it'll start right away an that's why I'm confused cause long as I start once in the Morning even lid I turn it right off it'll start right up all day but anyways wat should it read wen cracking just so I kno wen I check?

Tiny
Matttyw20
Dec 17, 2012.
I jus did it the battery went from 12.8 down to 9.69 when cranking I've got lifetime warranties on the starter and alternator think I should get both checked or what do you think
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Tiny
Matttyw20
Dec 17, 2012.
That voltage reading looks ok to me. If it cranks ok, maybe you need to look elsewhere for the problem. I'd do a fuel pressure test.

You can check mil codes, yourself. You use a jumper wire between the A & B terminals at the datalink connector. Then, turn key just till the dash lites come on, no further. The mil on the dash starts flashing, you count the flashes to get the codes. Your looking for two digit codes.

JDL
Dec 17, 2012.

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