HELP, motor pulsing,please read
#1
HELP, motor pulsing,please read
1995 flareside extended cab 6.5 foot long bed 5.0 automatic. When I first start the truck in the morning it will idle normally for about a minute or so then it will it pulses revving up and down constantly and after 5 to 10 min it will quit and idle normally. Even after the truck is warmed up if I rev the truck at all it goes right back to pulsing. I was told changing the coil would help since every time it pulses the battery gage goes down with the low revs. Idk what it is maybe a vacuum line but not for sure, please help. Thanks.
#2
Senior Member
A few things come to mind - possibly a bad/dirty idle air control valve, possibly a bad alternator (might explain why you are seeing the battery gauge dropping at the lower rpms - the alternator just can't handle the load of running the truck at low idle), possibly a bad throttle position sensor, possibly a vacuum leak.
Lots of possibly's. I'd look at the IAC and the TPS first. Search for threads on how to clean/test them - lots of good info.
Lots of possibly's. I'd look at the IAC and the TPS first. Search for threads on how to clean/test them - lots of good info.
#3
I didn't think about the alternator before, I got subs in my truck pushing about 1100 watts and I can watch the battery gage drop when the bass hits so I could of screwed up the alternator with that, I'll check the other things you suggested and thanks for the help