98 Explorer Sport Sputter/Stall

[Tozzi]

Hey guys..I have a 98 sport sohc with 104,000 miles..Its in basically perfect condition but lately I've had an issue with it sputtering/struggling a bit resulting in a stall a couple of times. The problem doesnt happen on a regular basis at all, but has happened maybe 3 or 4 times over the past 2 months (driven daily). The first time it happened I was backing out of a parking space and before I could shift from R to D it sputtered a bit then died (started right back up). 2nd time: Started up, pulled maybe 5 yards up in drive, then to park (leaving it to idle) and it stalled about 5 seconds into park (started right back up). 3rd time: Started up, sitting in park for about 10 seconds began to sputter, recovered, sputtered again, recovered. I did notice each time this has happened the a/c was on high (decent load on the battery) and on the last occasion I saw the amps drop, then recover, then drop again when it sputtered and recovered..Any ideas? (the alt was replaced last summer - it was also tuned up last year) Electrical wise I have not been that pleased with my volts with a load on the battery..I have a pioneer avic-n1 cd/dvd/etc which has a voltmeter built into it and I usually run at 13.4-7ish but at times it randomly will drop down to 12.6 and bounce back and fourth..

 

[Turdle]

I would try cleaning the IAC valve.

 

[bam_bam1ca]

Voltage dropping to 12.6 indicates that you are running on battery voltage only at that time. Put a volt meter at the battery and see what kind of readings you are getting. If you want to trust the voltmeter in the stereo, make sure of the ground and power connections so that you are not reading a voltage drop just in the connections to the stereo. I would check all of the battery cables and clean them, check the ground straps and charge circuit wiring. If your computer voltage is dipping too low the circuit that fires the coil pack may not be getting enough voltage to fire properly, and thus the stall.