My truck is acting funny 
I was in the last half of a 5 hour trip on the interstate to my parents' place with my tot when I heard/felt a backfire, and the engine kills. We were coasting, and I was able to fire it back up and kept it running as long as I didn't rev the vehicle high enough to go above 30 mph (it's an automatic, so this may have been the limp mode in 2nd gear?). We made it an extra couple hundred yards, before the truck would only run in park, then after about 5 min, it couldn't be started again. Had it towed to my parents' and I've been running some tests but getting weird results. Here's where I'm at:
Fuel seems great from volume and noid light tests, no change when adding starter fluid.
I don't have an HEI tester, but when I test for spark off the distributor, I get a couple sparks, then nothing, then a spark (accompanied by and engine cough) right at the end when the key is release from start to run. This is mirrored when I hooked a test light up from the icm signal switching circuit to Battery + (with the connector plugged in), the test light is ON Key-off-engine-off, test light is OFF Key-On-Engine-Off, test light comes on steady for about 30 sec during crank, then off, then on for a flash when the key is released.
From my research, the test light should actually be OFF during Key-off-engine-off, ON during Key-on-engine-off, and then obviously flashing during cranking. I swapped both the dizzy and the icm and found no change in the signal wire. I didn't test the PIP yet (didn't have all my tools at my parents' place), but that result seems rather strange for the PIP, should I be chasing an incorrect ground icm input wire to perhaps one of the pcm check wires? I ask this because a code reader is sensing that it's connected, but can't find the computer, and aren't those check circuits run for the first 30 sec or so of crank and then turned off?
Sorry this is so long.
(that's what she never said)
I was in the last half of a 5 hour trip on the interstate to my parents' place with my tot when I heard/felt a backfire, and the engine kills. We were coasting, and I was able to fire it back up and kept it running as long as I didn't rev the vehicle high enough to go above 30 mph (it's an automatic, so this may have been the limp mode in 2nd gear?). We made it an extra couple hundred yards, before the truck would only run in park, then after about 5 min, it couldn't be started again. Had it towed to my parents' and I've been running some tests but getting weird results. Here's where I'm at:
Fuel seems great from volume and noid light tests, no change when adding starter fluid.
I don't have an HEI tester, but when I test for spark off the distributor, I get a couple sparks, then nothing, then a spark (accompanied by and engine cough) right at the end when the key is release from start to run. This is mirrored when I hooked a test light up from the icm signal switching circuit to Battery + (with the connector plugged in), the test light is ON Key-off-engine-off, test light is OFF Key-On-Engine-Off, test light comes on steady for about 30 sec during crank, then off, then on for a flash when the key is released.
From my research, the test light should actually be OFF during Key-off-engine-off, ON during Key-on-engine-off, and then obviously flashing during cranking. I swapped both the dizzy and the icm and found no change in the signal wire. I didn't test the PIP yet (didn't have all my tools at my parents' place), but that result seems rather strange for the PIP, should I be chasing an incorrect ground icm input wire to perhaps one of the pcm check wires? I ask this because a code reader is sensing that it's connected, but can't find the computer, and aren't those check circuits run for the first 30 sec or so of crank and then turned off?
Sorry this is so long.
(that's what she never said)
