71 keeps dying and not starting...

[71wongbed]

I have been reading past posts for weeks now and slowly replacing parts and doing housekeeping under the hood, but I still have the same problems that have been bothering me for a few weeks.

So the truck just dies while driving, probably every other day. I drive to and from school which are 8 and 17 miles apart (two campuses) and it doesn't matter where (freeway, side streets, slow construction areas) or when, it just dies. I can try to restart it- sometimes the battery acts fully charged, cranks and I have to give it FULL throttle, fires up- and sometimes the battery acts drained, and If I wait a while (30-40 min.) there's a 50-50 chance that it will start up, FULL throttle again.

I have replaced the fuel pump, cleaned the tank completely, cleaned the fuel lines, replaced the alternator and the starter solenoid and kicked the truck very hard.
The battery tested good for autozone.
Probably not good, but I pulled the POS off the battery while running (the last time I had to jump it and drive it home) and the engine died.
Right now I have a trickle charger on it and will take it off first ting in the morning.

It's got a 350 small block, and for the most part stock all around.

I am stuck. I have done hours of research on the forums, hours of busting my knuckles under the hood, and still have to keep my bicycle in the bed just in case. Any help would be very appreciated.

[3quartertime]

Probably multiple problems.

Bad battery power could be charging circuit. New alternator could be bad. Could also be a bad connection either end of the circuit causing intermittent power loss.

Starting at full throttle could be flooding. More air with the carb open all the way. I've had vapor lock act like that, but it shouldn't affect the charging circuit.

What happens when it dies?

[Longhorn Man]

welcome to the forums.
You said when you unplug the bettery, the engine dies. While not a good way to test it, that says you are not charging.
Have you replaced the external regulator?

[rlm316]

When I bought my truck, the PO said mine did the same thing. I found a wire that was grounding on the exhaust when when it moved due to driving the truck. That wire cost him about $1k and the shop never found it. Check for that and do a voltage check at the battery, alt and regulator to check condition of charging circuit. You should see about 13-14vdc. Do this check again with all of your accessories on also. You may have a dead short somewhere in these circuits. Your starter could also be the cause of this, check the wiring to it and its general condition.
Good luck.

[cdowns]

have you changed the fuel filter IN the carb? if 4brl quadrajet theres a filter in the carb where the fuel line goes in ,large nut on the carb needs to b unscrewed to get it out

[68gmsee]

Definitely sounds like what's been mentioned above -charging problem and maybe even a flooding problem.

I'd buy a small meter (less then $20) set it on the VDC scale at 15VDC or higher and while running put pos lead on the + and neg lead on the - lead.
(I mention this in case there are others that are not familiar with testing a battery). It should read as mentioned above.

A fully charged battery will run your truck or car for quite some distance before dying. I once drove a small 76 datsun almost 100 miles with a fully charged battery before it died.

[71wongbed]

Thanks everybody.

I changed the ext regulator about two years ago. I guess I ought to for the money.
When it dies, it just dies, no stumble, no warning- similar to how it died when i pulled the POS lead on the battery.
Sounds like I've got a grounding issue, whether it be a short, not a good ground, or both. I've got a digital meter and as soon as I get home I'll check the voltage all around (the battery will be charged, so I can fire it up and diag...)

So, if the battery is not being charged, the truck is running off the battery, thereby depleting it more and more as I drive? makes sense

I didn't know there was a filter in the carb!

Could it be the terminal ends that connect to the battery? the POS is kinda eaten away, but looks like it gets a good connection.

I'm going to mess with it a bit, thanks for the help everybody!

[68gmsee]

"Could it be the terminal ends that connect to the battery? the POS is kinda eaten away, but looks like it gets a good connection."

Most definitely. The ends get corroded internally and lose connection. I had them do it on another vehicle.

The reason we didn't mention the cable/ground possibility was the you are able to start it after you charge it or wait 30 minutes or so. Wet cell batteries will recharge themselves to a certain point by the chemical reaction of the acid.

Also, there is a small filter inside the carb fuel pump inlet. Remove the large nut and pull it out and you should see the filter.

Let us know what you find.