cranks but won't start... could it be the battery?
06-25-2019, 10:26 PM
#1
Rennlist Member
Thread Starter
cranks but won't start... could it be the battery?
My 944 base did not start although the engine did crank. The other 'symptom' was that my trickle charger was blinking red, indicating a bad battery. I jumped the car and it started (although not quickly... took a few seconds of turning the engine over). So all of that indicates that the battery is bad. But to my understanding if the engine cranks but doesn't start, it's likely something else. Could the battery be strong enough to crank the engine but not fire the spark plugs? Thanks.
06-26-2019, 04:40 AM
#2
No, But it may be turning over slow and possibly linked with poor compression, fouled plugs etc is why it's not starting, was there a difference in cranking speed between your battery and the jump start?
06-26-2019, 07:56 AM
#3
Rennlist Member
Thread Starter
I did not notice a difference in cranking speed between the two. When it started with the jump start... I just noticed that it obviously took longer than normal to fire-up. I have not yet tried starting it again on its own. The thing that's confusing me, and leading me to the battery, is that the trickle charger is indicating there is something wrong with the battery. I also plan to clean off all of the connections at the battery, in case that's it.
06-26-2019, 08:40 AM
#4
Battery
Sounds like a dead cell. If so it won’t charge sufficiently. Pull it and take it to parts store have them charge and load test it. Sometimes it’s the simplest things.......
06-26-2019, 09:43 PM
#5
Unaffiliated
Low voltage on a 944 can fail to supply the crank sensors enough juice to trigger, so watch the tach.
If the tachometer bounces when you are cranking the sensors are working and your issue is likely elsewhere.
If the tach is not moving she's not going to pop.
YEMV
If the tachometer bounces when you are cranking the sensors are working and your issue is likely elsewhere.
If the tach is not moving she's not going to pop.
YEMV
06-26-2019, 10:47 PM
#6
Rennlist Member
Originally Posted by 944Fest (aka Dan P)
Low voltage on a 944 can fail to supply the crank sensors enough juice to trigger, so watch the tach.
What can happen is if the engine isn't cranked fast enough, the DME won't turn on the fuel pump.
06-26-2019, 11:26 PM
#7
Rennlist Member
What's the voltage at the battery? A good general rule is that it should not drop below 10V while cranking the engine over. Any lower than that and the coil may not develop the required voltage to fire the plugs.