So my 91 died on me again in traffic today

[LarsD]

Just like in my previous thread:

http://www.stangnet.com/mustang-forums/848168-so-my-91-died-traffic-my-way-work.html

I tightened the battery cables and it seemed fine for a couple hundred miles, and it did it to me again while I was rolling up on a light today. Acted the same exact way, hard to crank like the timing was way retarded/advanced, took me a few tries but it finally started. Now I'm gonna have to park this thing until I find out why it is doing this. Any ideas?

ETA: This is going to sound dumb as well, but the red top (battery) that I am running just turned 5 years old a couple months ago. Normally I would expect a dying battery to crank slow all the time, but it is possible for it to be fine one minute, then almost dead the next?

 

[jrichker]

Go to the nearest auto parts store and have them check you battery & charging system. It's free...

 

[LarsD]

Battery has been sitting a couple of hours. These are the voltages:

12.67 at rest (hood light on only)
10.5ish while cranking (fired up quick so I didn't get a good look)
14.4-14.5 while idling
14.3-14.4 at idle with headlights and the A/C vent running

The only thing that the car does that I think is odd is the voltage will dip down randomly to 13.5V when at idle. It doesn't do it consistently, regardless of what accessories are on. It has done this ever since I installed the 3G alt over a year ago (can't remember if it did it before or not), I first noticed it because I could hear the fuel pump's whine change pitch. Since I replaced the pump with a 255 unit it does it a lot less.

 

[Blown88GT]

Only a week ago I had a 5 year old DieHard Gold give out the same way. It would crank 1 or 2 times, then 'click-click" Only 2 minutes on a 6A charger would allow it to crank again...not normal.
It latest 67 mo out of the 100 mo waranty, was on a maintainer it's entire life. They don't make a Gold replacement in my size (mine is on the passenger side), so got a Silver which actually has more CCA. It's the same battery with less warranty.

I don't think the Optimas are worth the extra money unless you're mounting them in an unusual location or upside down. I'm not down on Optimas, I have 2 old Blue Tops in parallel on my main computer UPS. They sit on the floor beside the desk. AGM batteries are safe to use indoors.

BTW, your voltages look normal, except for the 10.5V while cranking. IIRC, 11.0V is better. Take it somewhere to have it load tested.

 

[BlackGT89]

You might have already done this, but check all of your grounds, especially the one going from the starter solenoid over to the front of the engine (timing cover maybe ?). Take it apart and clean it well even if it looks good to the naked eye. Also check the ground for your fuel injectors. Notice if you have any ground wires that are heating up when the problem occurs (without getting burned).

 

[LarsD]

You might have already done this, but check all of your grounds, especially the one going from the starter solenoid over to the front of the engine (timing cover maybe ?). Take it apart and clean it well even if it looks good to the naked eye. Also check the ground for your fuel injectors. Notice if you have any ground wires that are heating up when the problem occurs (without getting burned).

I went out and found that the bolt on the back of the driver's side head that secures a ground strap was tight, but the cable was loose enough that I could rotate it around easily. I went and dug up some washers and was able to tighten it up. When I took the cable off I went and turned the key on, the volt gauge in the cluster registered barely above 8V (which is how it was acting when it would die), after I tightened it back up it was reading considerably higher. Hopefully that was it.

 

[BlackGT89]

Hope so !

 

[DavidEwers]

glad to hear you got it fixed, what of part of Texas? From the photos I would say West Texas

 

[LarsD]

glad to hear you got it fixed, what of part of Texas? From the photos I would say West Texas

I troll around the Austin area.