problem starting after sitting for 7+ hours

[thebeastjuggalo]

I have a '95 jimmy 4.3 v6 and in the morning or after work when i go to start it, it doesnt like to fire up, so i sit there turn the key on for a few seconds then turn it off for a few seconds for about 3miniutes or so, then when i try to start it it tries to start but doesnt and then i try again like 2 more times and it fires up.

i have put it in the shop and they hooked it up to diagnostics and nothing came back wrong, and the fuel pressure at the pump is slightly above factory spec's.

any ideas?

thx.

[DelCoch]

Check your battery with a load type tester - autozone will do it for ya. I had the same problem on my '95, the battery was weak, although it appeared to be cranking over ok, the starter was pulling all the current and not leaving enough for the fuel pump to reach max pressure during the 2-seconds the fuel pump runs when the key is turned on. After several times of "key on"-"key off" it would finally start. Battery checked out weak and a new battery solved problem.

In the meantime, you might try turning the key on and wait 1-second before engaging the starter, thus letting the fuel pump build up to max pressure.

When you turn the key on the fuel pump runs for 2-sec and then the key must be off for 10-sec before the pump will run again. The fuel pump has to reach at least 61 psi to start the engine. After the 2-sec period the fuel pump shuts off and the pressure starts to fall to about 55-58 psi.

Check back and let us know what you find - could be another problem.

[thebeastjuggalo]

im pretty sure its not the battery, about a week ago i got it back from the mechanic again and he said it was the battery also because it would start right up when he connected the battery charger to it.

the battery that was in there only put out 450cca and i went to autozone and got one that puts out 700cca and it does the same thing it did before.

[DelCoch]

Being pretty sure doesn't cut it - do a load test on the battery regardless of age, often batteries set on the shelf for years before being sold, especially non OEM types - maybe the battery cables need cleaning.

If it starts ok with jumper cables or a battery booster in place, then it's has to be related to the battery. Put a volt meter across the battery when the key is off and all lights off, including the under hood light and see if something is draining your battery when the truck is parked. Also check how many volts are being drawn when the starter is engaged. Maybe the starter is going bad and drawing too much current. Do you have any after market accessories that may be draining your battery, like a radio amplifier that stays on when the truck is parked?

You need to check these things out - only takes a minute to check them.