94 4.0 won't start very intermittent spark
#1
94 4.0 won't start very intermittent spark
Hi everyone,
I'm kind of at a loss, I have a 1994 Ranger 4.0 4x2 that has been in the family since new.
It had some issues, and sat in the garage for a while. The battery died, and I used the "start" feature on my cheapie Harbor Freight battery charger to jump it. Well the truck never started after that, so I decided to let the battery charge for a few hours and try again. It still wouldn't start, so I grabbed one of the plug wires, yanked it off, put a clean plug in it and checked for spark. there was no spark.... Checked the other wires, same thing.
Unfortunately, using the start feature fried the powertrain control module. I threw parts at it hoping to resolve the issue.
Ignition control module
Powertrain control module
Coil pack
checked all fuses and relays.
all seems to be ok.
Now there is very intermittent spark. There's no specific sequence in the irraddic spark that I am receiving when trying to start the truck. Do any of you fine people have any ideas?
I'm kind of at a loss, I have a 1994 Ranger 4.0 4x2 that has been in the family since new.
It had some issues, and sat in the garage for a while. The battery died, and I used the "start" feature on my cheapie Harbor Freight battery charger to jump it. Well the truck never started after that, so I decided to let the battery charge for a few hours and try again. It still wouldn't start, so I grabbed one of the plug wires, yanked it off, put a clean plug in it and checked for spark. there was no spark.... Checked the other wires, same thing.
Unfortunately, using the start feature fried the powertrain control module. I threw parts at it hoping to resolve the issue.
Ignition control module
Powertrain control module
Coil pack
checked all fuses and relays.
all seems to be ok.
Now there is very intermittent spark. There's no specific sequence in the irraddic spark that I am receiving when trying to start the truck. Do any of you fine people have any ideas?
#2
Welcome to FTE.
Scan the engine computer for stored, pending, or set, trouble code clues & post All code Numbers, as they can offer up good trouble shooting tips.
What kind of "issues" caused the vehicle to sit unused for so long????
Did you use the jump start feature at any time After the new parts were installed????
Were the new parts bench tested in the store before you left with them???? Just because parts are new doesn't automatically mean they're good. I've seen plenty of faulty new ones right out of the box, so I have the store bench test all of my electrical replacements before leaving with them & yes, we've found faulty ones right out of the box!!!!
If the same battery is still in the vehicle, perform an under load voltage drop test on it across the battery posts, then across the cable connectors on both ends of the cable runs with your multi-meter on the 20 volt DC range, while the head lights & blower motor are on.
If the battery has set uncharged for an extended time, the plates are likely sulfated & if so, they may not be providing enough under load voltage to run the ignition system with minimum voltage for it to make a healthy spark on a start, while running the starter motor & fuel pump.
We only have 12 volts to work with, so All of our B+ & B- battery to engine & body connections need to be clean, bright & tight, to have good low resistance electrical connections that'll prevent voltage drop under load while starting & running.
Always best to use a battery charger on a low rate of charge, to Slowly bring a battery state of charge back up, rather than jump start a dead battery & expect our alternator to recharge a dead battery, as it isn't designed to do that, just to quickly put back whats taken out on a start & to keep the battery topped up while running with lights, AC, ect on. The alternator will dump Big Amps into a flat battery, overheating & damaging both!!!!
Seeing as how it set unused for a spell, any signs that critters may have been chewing on wiring insulation???? They like it for some reason.
A bunch of thoughts for consideration, let us know how your trouble shoot goes.
Scan the engine computer for stored, pending, or set, trouble code clues & post All code Numbers, as they can offer up good trouble shooting tips.
What kind of "issues" caused the vehicle to sit unused for so long????
Did you use the jump start feature at any time After the new parts were installed????
Were the new parts bench tested in the store before you left with them???? Just because parts are new doesn't automatically mean they're good. I've seen plenty of faulty new ones right out of the box, so I have the store bench test all of my electrical replacements before leaving with them & yes, we've found faulty ones right out of the box!!!!
If the same battery is still in the vehicle, perform an under load voltage drop test on it across the battery posts, then across the cable connectors on both ends of the cable runs with your multi-meter on the 20 volt DC range, while the head lights & blower motor are on.
If the battery has set uncharged for an extended time, the plates are likely sulfated & if so, they may not be providing enough under load voltage to run the ignition system with minimum voltage for it to make a healthy spark on a start, while running the starter motor & fuel pump.
We only have 12 volts to work with, so All of our B+ & B- battery to engine & body connections need to be clean, bright & tight, to have good low resistance electrical connections that'll prevent voltage drop under load while starting & running.
Always best to use a battery charger on a low rate of charge, to Slowly bring a battery state of charge back up, rather than jump start a dead battery & expect our alternator to recharge a dead battery, as it isn't designed to do that, just to quickly put back whats taken out on a start & to keep the battery topped up while running with lights, AC, ect on. The alternator will dump Big Amps into a flat battery, overheating & damaging both!!!!
Seeing as how it set unused for a spell, any signs that critters may have been chewing on wiring insulation???? They like it for some reason.
A bunch of thoughts for consideration, let us know how your trouble shoot goes.
Thread
Thread Starter
Forum
Replies
Last Post
lonestarfordman1980
1948 - 1956 F1, F100 & Larger F-Series Trucks
6
05-14-2008 05:45 PM
dpm1057
Explorer, Sport Trac, Mountaineer & Aviator
5
05-08-2007 07:19 PM