Motor is starting, but sounds like low battery

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Motor is starting, but sounds like low battery

jarek_rugby
Hello to all after few months break :)
All that time i have problem with strating my 1986 EFI 302 2wd.
It starts but during starting operation it sound is like very low battery . I refurnished my starter but it did not helped. When i am going for ride it is always question: will it start?
Any suggestion ? I read a lot of posts and i know that there are people who has the same problem.
regards
Jarek
Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973
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Re: Motor is starting, but sounds like low battery

Gary Lewis
Administrator
Hello!

I would check the voltage of the battery when the engine is running.  It should be around 14.4 volts.  If it is only around 12 volts or so the alternator isn't working correctly.

Then check the voltage of the battery the next morning after you've driven the truck.  The voltage should be around 12.8 volts.  If it is much lower than that you may have something in the truck that is pulling the battery down.  To check that, pull the positive battery cable off the battery and check for current flow from the battery's positive post to the positive cable.  You shouldn't see more than about .020 amps.  If more, you need to find out what is doing it.

Or, you may have a bad battery.  Over here the auto parts stores will test the battery.  Can you have it tested?
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Motor is starting, but sounds like low battery

jarek_rugby
Hi Gary,
Yes, i checek all things :)
Battery is 8 months old, voltage is over 14 when engine is working, battery voltage in the morning is 12,1.
I did not check "bad" power consumtion :)
While i am strating engine it sounds like "i have problems with turning flywheel" :), and after this engine is starting :)
I will record this sound and will send to You but not before Saturday .
regards
Jarek
Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973
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Re: Motor is starting, but sounds like low battery

Gary Lewis
Administrator
Voltage of 12.1 is bad news.  Something is pulling the battery down during the night and you have to figure out what.

One way to start is to pull the positive battery cable and put a test light between the positive post and the cable.  With the door shut so the dome light is off the test light should not come on.  But if it does start pulling fuses one at a time to see which one shuts the light off.

But it is entirely possible that you won't find it by pulling fuses since a lot of things are protected via fuse links and not fuses.  If you don't find it via pulling fuses then you'll need to do a bit more sleuthing.  You can pull the fuse links off the starter relay and see if the problem goes away.  But, you may have a blown diode in the alternator, so pull the connection to the alternator and see if the light goes off.

Again, don't forget that the dome light will cause all sorts of false positives if you leave the door open.
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Motor is starting, but sounds like low battery

Pete Whitstone
In reply to this post by jarek_rugby
I think Gary is probably on the right track with something pulling the battery down, but another thing to check is the condition of the big cables going from the battery to the starter. This includes the short one going to the starter solenoid, the longer one going to the starter "hot", and then the ground cable. On my truck the ground cable goes straight from one of the starter mounting bolts to the negative side of the battery. I don't know if that's the stock arrangement or not, but make sure the engine block has a good, appropriately sized ground path back to battery negative. A lot of times it's forgotten that the ground has to carry the same current as the hot side.

Not only make sure the cables themselves are in good condition with no internal corrosion, but also make sure that the mounting points are all cleaned and are providing good contact. Steel wool or similar can be used to get down to good solid conductive metal. And don't forget the battery terminals themselves.

Good luck, hope you get things sorted!

Pete
81 F150 Flareside, Edelbrock Pro Flow4 FI, hydraulic roller 351W, E4OD, 4x4, BW1356
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Re: Motor is starting, but sounds like low battery

jarek_rugby
In reply to this post by Gary Lewis
Hi Garry
I will try to do this on Saturday :)
But not sure that i have enough knowlage to do it :)
Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973
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Re: Motor is starting, but sounds like low battery

ArdWrknTrk
Administrator
Jarek, I find it more simple to start at the starter relay on the inside fender.

Remove the keys from the ignition and close the doors.
Remove the positive battery cable from the starter relay and attach the meter to the cable.
Be careful to not ground the cable!

Touch each of the wires that were held by the same nut to the relay.
Which one (if any) create a reading above 0.020A?
This will give you a good idea where to proceed.
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Motor is starting, but sounds like low battery

jarek_rugby
on Saturday :) i'll give You answer
Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973
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Re: Motor is starting, but sounds like low battery

jarek_rugby
I am back.
I think that it could be problem with my battery.
I have checked all fuses - nothing, no bad power consumption, i also checked starter relay wires - nothing.
Charging from  alternator - 14,5 V. First time when i checked voltage (during engine work) it was 13,2, so i thought that something wrong is with voltage regulator but next time the voltage was OK.
I charged battery with rectifier and after that i checked voltage - 13,6 V.
After one  day (i have disconnect battery from truck) the voltage on battery - 13,2 V.
What do you think ? is it normal?
my battery :

Chicks dig us 'cause we play RUGBY
F 150 1986 302 ci EFI
Pontiac Firebird 400 ci 1973
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Re: Motor is starting, but sounds like low battery

ArdWrknTrk
Administrator
13.3V is a very high reading for a battery at rest.

12.5~6 is typical.
But it may be you have an exceptional battery!
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.