jks

This 1999 astro van, 4.3 vortec had a no start condition. Testing tools used, volt/ohm meter, test light, led test light, snap-on mt2500 scan tool, fuel pressure gauge, spark tester. First repair performed, scanned codes, P0336 present, scan tool trouble shooter stated ckp sensor 'a' (1x/24x) out of range. Possible causes bad crank sensor, which is located on the timing cover. being a conversion custom "van" I did not want to pull dog house off yet to do further testing. I ordered a crank sensor, upon removing the old crank sensor it was evident that motor oil was leaking from the internal working of the sensor to the electrical plug connector, replaced part. Cranked engine, NO START. check Voltage and ground at the crank sensor, okay. Switch to a/c volts checked 'pulse' voltage at sensor, okay. Tried to remove dog house, no luck, got it marginally sideways, pulled coil wire from distributor, had spark, pulled one plug wire, had spark, and it started during test. ??did not find problem?? ran great, no codes, using mt 2500 reset computer/relearn/ crank,cam correlation etc. drove 93 miles, died, no start. SECOND try. checked codes, p0463 fuel sender problem, (fix later) and p1351 ignition coil 1 and 4 control circuit high voltage. I removed the passengers seat, dog house. fuel pump pressure 68 psi prime, holds at 62 psi. checked ecm and related fuses, okay. Parts guy told me to change to ignition module, its next to the coil, put on the white grease and installed it. still no change. cleared codes, cranking would still set p1351. Got serious then, two repair manuals, retested crank sensor, good. check "pink" 12 volts at module and crank sensor and fuel injection connector. I did not check cam sensor at this time, book said it would not effect starting. Annoyed over the lack of progress, I rechecked all the basics, then using a test light and a led test light check injector pulse, Pink 12volts, and using one of the six remaining injector wires. Computer pulsed the ground and flashed the light, good. rechecked spark, good at coil, good at plugs, pulled one wire at a time, had spark. Checked coolant temp, tps throttle position sensor, fuel quality, good. In the last ditch effort, I was forced to consider parts swapping. It was crazy, I had fire, fuel, injector pulse, air, all the things needed. It would just freely crank, at the last it would stubble at little for a second or two. I decided to pull the distributor cap and check to see if the rotor was indeed rotating. PROBLEM FOUND the pancake vortec cap had signs of water and rusted ring. cleaned sensor and ring, checked cap with ohm meter, checked okay, re-installed but it did not start. Ordered a new cap and rotor, installed and it roared to life. No codes, no problems, ran like a new engine. Finally, The distributor cap was arching the coil spark to multiple spark plugs at the same time. I checked one at a time and did not catch to problem. I rightly cannot say that a cap and rotor would have been the only problem, but it was a major cause. I used some postings from this site, and others, read books, used major brain power and effort, and finally fixed this troublesome van. Hope my learning curve will help others. ps today had a 2002 s10 4.3 had coil spark, nothing coming out of the cap, fuel psi marginal at 52 psi, rain water signs again in distributor, rotten cap, rotor 1/2 inch burned spot. replaced and it ran good, that astro education is paying off.