Starting after dead battery

[Mamushi]

Is there a trick to starting a Gen I after a dead battery? I went thru this a couple times before: Car wouldn't start after recharging a dead battery. After many tries, it finally starts up under WOT with a huge cloud of black smoke from the exhaust... and then took a few drives to relearn the fuel management, I guess.

I'm back to not being able to start right now after I let the battery go too low. Seems like the engine goes back and forth from not enough fuel and too much fuel.

I searched and couldn't find something quickly, but I have seen threads before on this. Let me know if there is any threads you think I should review. Thanks.

[Mamushi]

file-5.jpg
Not sure if this pic will come thru, but was looking to test out this new hard top from Autoform in the nice weather. Took a long while to get to me, but I am please with the quality so far.

[Steve-Indy]

How old is battery? In my experience, if a battery has gone dead more than once, it is seldom back to "normal" after recharging. Have you tested the voltage half an hour after taking battery off the charger? These cars are certainly sensitive to low voltage.

[Mamushi]

It’s an Optima battery that I replaced the beginning of the year. I remember it being difficult to start after I replaced. I will check voltage tomorrow and let you know. Maybe too many start attempts drained the battery..

[ViperTim]

Me and my father discussed this.
What does the fuel management learn? It learns your car. Which is 20 years old.
I myself have 0 issues starting her after a winter without a battery in it. Fires up instantly and runs just like every other startup.
Either my tune is spot on and nobody else's is, or there's issues with the other cars.
I choose to believe the second one.
My theory, read just a theory, is that the fueling has learned your car. And your vacuum leaks.
The hoses are 20 years old. Ofcourse they are cracked.
I believe that everyone who has this issue, has vacuum issues.

Prove me wrong, because this is just my theory.


Edit: checking battery voltage tells you absolutely nothing. It's the CCA that goes down with the battery's age and use. And that you cannot just check with a multimeter from pepboys. So that's just a waste of time.
Either it cranks, if it does then CCA is good, or it doesn't then the battery needs replacing. Simple as that, there's no science.

Voltage =/= power.
Ampere =/= power.
Voltage + amp == power.
If there's not enough amps, voltage dips (during crank! Not static). If there's not enough amps, battery is toast.

[uvbnbit]

I seem to remember that Optima's (red top?) were notorious for having "issues" in a Viper. This was years ago, but who knows.

[Steve-Indy]

Actually, ViperTim, checking the battery voltage does tell you the charge status of the battery. If you have a Viper Service Manual, you will find that this is supported by said manual...can be found in the beginning of the section on electrical info and issues. I find this to be a quick, easily first step in the diagnostic process...as well as a monitor for charging a battery that has failed to start the car. I suspect that many, many more Viper drivers have a voltmeter than have a means to measure CCA. When I buy a new battery for one of the Vipers, I always ask the sales person to show me the voltage and CCA in the store before I buy the battery...regardless of the date label on it.

As you know and have stated...there is more to these issues than voltage. I usually start there, and try to open a true conversation...telephone, not keyboard...moving from simple to complex testing well before throwing random parts at a problem. Much of the outcome depends on the appetite and experience of the owner and their access to tools. Sometimes it is best to suggest that they see a dealer rather than risk harming the Viper.

By the way, there are scores of reports of Gen I, II, III, and IV Vipers with symptoms similar to those stated in the original post...all of which were cured with a new battery. Certainly, some of this applies to Gen V cars as well.

uvbnbit, I agree that the "Optima thing" is a whole different issue.

[quickster2]

I would invest in a battery tender and not allow a dead battery. Static voltage in a resting battery will give many clues as to a problem. My Cayenne S is very sensitive to low voltage for all of the computers. Even when it sits, i make sure to charge the battery before starting. Cheap insurance.

[Mamushi]

Thanks for all the replies. I let it sit on trickle charger to full charge overnight. After letting it sit off the tender for an hour, it measured 12.5 volts. Still doing the same thing when trying to start it.


I have a trickle charger. But, like a dummy, I forgot to put it on recently and let it let it sit too long before realizing it. I bought the car last year and I had this same problem last winter, so I replaced the battery. It still took a while to finally start and quite a few drives to actually start running right. Maybe Vipertim's vacuum leak theory is worth investigating...

Taking the wheel off and getting the access panels off was a pain in the neck, so I bought the red top Optima because I thought it was most likely to hold charge in cars that sit a lot. Hadn't heard there may be an issue with using them in Vipers. Damn thing wasn't cheap, either! Haha

[Lalmeida617]

Actually, ViperTim, checking the battery voltage does tell you the charge status of the battery. If you have a Viper Service Manual, you will find that this is supported by said manual...can be found in the beginning of the section on electrical info and issues. I find this to be a quick, easily first step in the diagnostic process...as well as a monitor for charging a battery that has failed to start the car. I suspect that many, many more Viper drivers have a voltmeter than have a means to measure CCA. When I buy a new battery for one of the Vipers, I always ask the sales person to show me the voltage and CCA in the store before I buy the battery...regardless of the date label on it.

As you know and have stated...there is more to these issues than voltage. I usually start there, and try to open a true conversation...telephone, not keyboard...moving from simple to complex testing well before throwing random parts at a problem. Much of the outcome depends on the appetite and experience of the owner and their access to tools. Sometimes it is best to suggest that they see a dealer rather than risk harming the Viper.

By the way, there are scores of reports of Gen I, II, III, and IV Vipers with symptoms similar to those stated in the original post...all of which were cured with a new battery. Certainly, some of this applies to Gen V cars as well.

uvbnbit, I agree that the "Optima thing" is a whole different issue.

My advise is to listen to Steve. He owns a pile of Vipers and has not steered me wrong yet!

[ViperTim]

(lots of goodies)

Surely I agree with you. But the static voltage isn't what matters, it's how well it holds voltage during load (starter for example). But as you say, static voltage can give you hints and help you on the way.
It can easily be heard on the starter. If the starter sounds slow and sluggish then there just isn't enough juice. Quite simply.
If the starter sounds just like normal then you can assume (but not verify) there's enough juice.
But voltage during load can dip enough that the starter sounds fine yet the coils don't have enough voltage for proper spark.
I don't know how sensitive these cars are on that though. Some cars are super sensitive others just don't care...

Measuring CCA is difficult for somebody like you and me. Nothing I ever do. If I have the symptoms above I just buy a new battery. If that wasn't the problem then I just put that battery to use somewhere else. So far I haven't had an occasion where the new battery was unnecessary.

New battery can do wonders on many occasions.

[ViperTim]

Thanks for all the replies. I let it sit on trickle charger to full charge overnight. After letting it sit off the tender for an hour, it measured 12.5 volts. Still doing the same thing when trying to start it.


I have a trickle charger. But, like a dummy, I forgot to put it on recently and let it let it sit too long before realizing it. I bought the car last year and I had this same problem last winter, so I replaced the battery. It still took a while to finally start and quite a few drives to actually start running right. Maybe Vipertim's vacuum leak theory is worth investigating...

Taking the wheel off and getting the access panels off was a pain in the neck, so I bought the red top Optima because I thought it was most likely to hold charge in cars that sit a lot. Hadn't heard there may be an issue with using them in Vipers. Damn thing wasn't cheap, either! Haha

As stated, it's just a theory. But it would be fun if you could find out if it's true or false.
Try squirting a little bit of starter spray around the vacuum hoses (not too much) and if the RPM increases while you've sprayed a little then you can have a vacuum leak there.
I don't do this often enough on my cars...