77 Bus - 2.0L FI - difficult to start
Posted: Fri Feb 14, 2014 10:29 pm
Symptoms -
Engine difficult to start when cold. It requires cranking for several 10 second attempts before it catches briefly and then dies. Several more attempts to start. It starts briefly and then immediately dies. This start - run a few seconds - die cycle repeats until the engine CHT gets to about 200F. Starting the engine and giving the engine some gas occasionally "muscles through" the urge to die. Once running and warmed up - engine runs fine.
Troubleshooting steps taken -
Removed AAR - cleaned, opening and resistance check according to procedure on website - all good.
CSV - removed CSV from plenum and checked for fuel spray - no spray.
Swapped out CSV - still no spray
Checked voltage to CSV - found voltage, but also found that one of the two wires to the CSV was pushing back out of the connector and not making contact.
Engine would now start without much cranking (the CSV is now working) - however it would run for a few seconds and die again.
At this point I suspect either vacuum leak or FI injector harness has a fault.
Removed all hoses, AFM, vacuum lines and checked them for crack/leaks - none found.
Removed the FI harness - it is brittle and cracked. Considering the earlier find with the CSV connector I carefully disassembled the wiring harness, checked continuity of all the wires, checked for worn insulation. Found a couple wires with worn insulation - fixed the insulation and then re-covered the harness.
Reinstalled the harness, hoses, AFM, vacuum lines.
Engine starts immediately. Adjusted the timing, but idle was not stable. I think I hear a vacuum leak. Determine that the CSV casing is leaking air. Swap the old CSV back on to the engine.
Engine starts, idles smoothly.
Tomorrow morning is final test - I will start it up early in the morning.
Engine difficult to start when cold. It requires cranking for several 10 second attempts before it catches briefly and then dies. Several more attempts to start. It starts briefly and then immediately dies. This start - run a few seconds - die cycle repeats until the engine CHT gets to about 200F. Starting the engine and giving the engine some gas occasionally "muscles through" the urge to die. Once running and warmed up - engine runs fine.
Troubleshooting steps taken -
Removed AAR - cleaned, opening and resistance check according to procedure on website - all good.
CSV - removed CSV from plenum and checked for fuel spray - no spray.
Swapped out CSV - still no spray
Checked voltage to CSV - found voltage, but also found that one of the two wires to the CSV was pushing back out of the connector and not making contact.
Engine would now start without much cranking (the CSV is now working) - however it would run for a few seconds and die again.
At this point I suspect either vacuum leak or FI injector harness has a fault.
Removed all hoses, AFM, vacuum lines and checked them for crack/leaks - none found.
Removed the FI harness - it is brittle and cracked. Considering the earlier find with the CSV connector I carefully disassembled the wiring harness, checked continuity of all the wires, checked for worn insulation. Found a couple wires with worn insulation - fixed the insulation and then re-covered the harness.
Reinstalled the harness, hoses, AFM, vacuum lines.
Engine starts immediately. Adjusted the timing, but idle was not stable. I think I hear a vacuum leak. Determine that the CSV casing is leaking air. Swap the old CSV back on to the engine.
Engine starts, idles smoothly.
Tomorrow morning is final test - I will start it up early in the morning.