I have reviewed many sources that helped guide me to this point - all too common problems with what I just experienced!
Out-of-town mechanic replaced Fuel Pump and Fuel Filter. Traveled ~600 miles on way back home, van cut off - cranks normally, no-start. Different mechanic told me no power to Auto Shut-Down Relay (ASD)#12 fuse. Fuel pressure still at 49 p.S.I. I towed the van home to do the repairs to save money.
I tested for Camshaft (CMP)/Crankshaft (CKP) Position Sensors. They appeared to be working after testing at connector to Coil Pack - still no spark. I took off the CKP and nothing appeared to be damaged and flywheel OK. I know about the 0.030 gap. I attempted to remove the CMP and ended up breaking the tab. The camshaft is turning. Installed new CMP, still with no-run condition and no spark.
I checked the coil pack and it had high resistance at both the primary and secondary. Replaced with new one since the resistance was very low and in specification. Still no spark. I bypassed the ASD relay to see if I can get the engine to run with the pedal to the floor. It backfired and ran at very low speed like it was starving for air/fuel. Started again without touching the gas pedal and it just kept cranking.
I know the Engine Control Module (PCM) has to be working - possibly not like it should. The indicators on the dash are all working correctly. The DTC is working when I received code 42 twice because I removed the relay and bypassed it. My scanner gave me a code P1388 and P1389. Erased the PCM, reinstalled the relay, restarted engine, and no DTC codes - 12 and 55 and scanner did not display any DTC codes. I checked all the wiring and found nothing suspicious. Finally, I pulled the air intake plenum to gain access to the rear bank to check the plugs. All checked good with excess fuel, of course. The compression on average are 170 - 180 after I pulled the plenum off. Before on front bank, compression checked at average for cylinder 2 (138), 4 (125), 6 (131).
The spark plug wires resistance are within spec. The connector to coil pack battery lights up once at ignition "ON" and blinks at cranking. Then checked other pins for 1/4, 2/5, and 3/6 blinks during cranking; yet, no spark.
Last, tomorrow I will install all new spark plugs (0.050 gap platinum - as recommended) and plan to check the Oxygen Sensor and EGR tube before I put everything back on. Over a year ago, I replaced the EGR valve and cosmetically, it looks rusted. I will test it with vac. Pump before I put the plenum back on. The only thing I have not checked are the two sensors for the Throttle Body. I know that is not the root cause of the no-run (start) condition. It is much easier to work on engine while the plenum is off. I would hate to have to spend <$200.00 for an Engine Control Module since that seems to be doing what it is supposed to do. I have already spent $1,000 credit card charges just this month on the van - I know that it is 16 years old. I will remove the gas tank to check everything since the mechanic did not tighten one of the bolts for the bracket. I just want to be sure that no vent lines or wiring are pinched above the gas tank. The fuel line is fine.
Thursday, September 13th, 2012 AT 7:51 AM