2.8 dies randomly

[Tylersbronco2]

my buddy has a 2.8 b2 and he has a problem or maybe a few problems. he has replace the altenator the battery the power wire that runs to the battery the solenoid the fuel filter on the carb and rebuilt his carb but still it will start up and will only stay running if he keeps on the gas alot if he lets it out it dies. then it wont start up and give it a minute and it starts again and dies again rarely it will stay running and drive it for about 15 minutes and lights will go dim and blinkers stop working and it dies and then it acts like the battery is dead and just clicks when you try to start it but if you push start it it will stay on but if you let the rpms get low it dies we have no idea whats up with it please help

 

[killj0y]

Check and maybe redo the big 3? Defective alternator? check fuel and ignition since it starts and runs might be that.

 

[ZMan]

Has he check all of the vacuum lines to make sure there aren't any leaks? Put a vacuum gauge on it to make sure its pulling 20lbs at an idle (if he can make it stay there long enough)

 

[kimcrwbr1]

Sounds to me like he needs to get new battery cables. Fully charge the battery and while it is charging sand all the grounds metal to metal. Clean all the electrical connectors with elect cleaner and use some dielectric grease when putting them back together. Once you are sure all the wiring is good measure battery voltage then hook it up and start it. Run it for a few minutes and then check voltage at the battery at around 1500 rpm you should have no more than 2 volts over the fully charged battery. Then turn the lights and heater blower on high and at 2000 rpm you should have no less than .5 volts above fully charged battery. So on the no load test if the battery is 12.8 volts fully charged voltahge at the battery should be no more than 14.8 volts at 1500 rpm, and the second test battery volts at 12.8 it should be no less than 13.3 volts at 2000 rpm. If it is still running on the computer you must have all the sensors plugged in and vacuum lines correct before you even start it if it is the 2.8 V-6. that includes the one on the air filter IAT intake air temp. Start from the beginning do a compression test check the vacuum pressure but make sure the charging system is up to par before yo do any ignition/computer diag. Without good compression or power nothing else really matters. If it is over voltage you can burn up components and under volts and your spark will suck. I dont believe you will get over 18 hg on the vacuum at an idle but should be 20 and steady anywhere above idle anything above 17hg and steady at an idle is acceptable.