hangarhouse
New member
1965 Scout 80
152, 3 speed, 4WD, 4.88 axles
Stock, unrestored except for maintenance and spring re-arch, fuel system upgrades. (picture wheeling for attention)
New Hamilton Fuel Injection Electronic Distributor/coil/wires, Weber 32/36
Recent (9 years ago) custom made steel fuel tanks (copy of originals expanded to 11 gal ea), 5/16 steel fuel lines, electric selector valve, filters
Recent OEM Fuel Pump
Was running poorly when started this season (jumpy idle, no power), upgraded to HFI distributor, replaced Weber carb. Drained, replaced fuel. replaced filters. Started, ran, timed by ear. Ran good, idled high, but pinged. Set timing with lite/vac advance plugged at 8 BTDC. Turned off, started but would not run above very poor idle. Advanced timing to get running, ran good, but timing measured 20 BTDC. Set timing with lite at 10 BTDC. Turned off, same problem. Removed PCV setup, plugged manifold port. Had to advance distributor to get running again, same condition. Tuned off installed vac gage. Started, would not run over idle. Vac at 5, bouncy. Advanced distributor until running good vac at 17 steady. Checked timing, 20 BTDC. Reduced idle stop to ~ 450, started running poorly, vac at 5. Increased idle stop screw slowly, vac jumps to 17, runs good above ~ 650 RPM. Turned off, started, only ran it idle. Measured timing, 12 AFTER TDC. Repeated 3 more times, same condition. Pulled new distributor, good end play, gear looks good. Mech advance works good.
Summary: Timing retards about 25 degrees when engine shut off (or idle stop is reduced to less than 500) and then re-started and timing jumps about 25 degrees. When timed at +12, it runs well to 4200 RPM, but won't restart. When timed to +20, runs lake a scalded dog (and pings under load) and will restart with a noticeable improvement when the timing "jumps".
Old distributor gear looks fine, normal wear. OK oil pressure on straight 30 with 1 STP. 5 psi hot.
Owned for 13 years, low miles, AZ truck. Driven less than 500 mi per year Nov-April last 13 years. Stored summers.
If I was going to guess, it seems like either:
1. The crank thrust bearing is worn badly and the crank moves forward enough to cause backlash in the cam drive gears or
2. The cam thrust surfaces are worn enough for the cam to move causing backlash in the distributor drive gears or
3. The cam drive gears are badly worn or
4. Combinations of above.
I have had to adjust and rebuild/replace the clutch master and slave cylinders recently (2 years ago) to get adequate clutch travel, and clutch feel has changed over time (some noise). Starter motor has just started acting off-nominal (no engagement with flywheel on first key, engages on 2nd or 3rd key).
My question: Is it possible for crank movement (plus gear wear) to be the culprit here? Any other ideas?
Thanks!
152, 3 speed, 4WD, 4.88 axles
Stock, unrestored except for maintenance and spring re-arch, fuel system upgrades. (picture wheeling for attention)
New Hamilton Fuel Injection Electronic Distributor/coil/wires, Weber 32/36
Recent (9 years ago) custom made steel fuel tanks (copy of originals expanded to 11 gal ea), 5/16 steel fuel lines, electric selector valve, filters
Recent OEM Fuel Pump
Was running poorly when started this season (jumpy idle, no power), upgraded to HFI distributor, replaced Weber carb. Drained, replaced fuel. replaced filters. Started, ran, timed by ear. Ran good, idled high, but pinged. Set timing with lite/vac advance plugged at 8 BTDC. Turned off, started but would not run above very poor idle. Advanced timing to get running, ran good, but timing measured 20 BTDC. Set timing with lite at 10 BTDC. Turned off, same problem. Removed PCV setup, plugged manifold port. Had to advance distributor to get running again, same condition. Tuned off installed vac gage. Started, would not run over idle. Vac at 5, bouncy. Advanced distributor until running good vac at 17 steady. Checked timing, 20 BTDC. Reduced idle stop to ~ 450, started running poorly, vac at 5. Increased idle stop screw slowly, vac jumps to 17, runs good above ~ 650 RPM. Turned off, started, only ran it idle. Measured timing, 12 AFTER TDC. Repeated 3 more times, same condition. Pulled new distributor, good end play, gear looks good. Mech advance works good.
Summary: Timing retards about 25 degrees when engine shut off (or idle stop is reduced to less than 500) and then re-started and timing jumps about 25 degrees. When timed at +12, it runs well to 4200 RPM, but won't restart. When timed to +20, runs lake a scalded dog (and pings under load) and will restart with a noticeable improvement when the timing "jumps".
Old distributor gear looks fine, normal wear. OK oil pressure on straight 30 with 1 STP. 5 psi hot.
Owned for 13 years, low miles, AZ truck. Driven less than 500 mi per year Nov-April last 13 years. Stored summers.
If I was going to guess, it seems like either:
1. The crank thrust bearing is worn badly and the crank moves forward enough to cause backlash in the cam drive gears or
2. The cam thrust surfaces are worn enough for the cam to move causing backlash in the distributor drive gears or
3. The cam drive gears are badly worn or
4. Combinations of above.
I have had to adjust and rebuild/replace the clutch master and slave cylinders recently (2 years ago) to get adequate clutch travel, and clutch feel has changed over time (some noise). Starter motor has just started acting off-nominal (no engagement with flywheel on first key, engages on 2nd or 3rd key).
My question: Is it possible for crank movement (plus gear wear) to be the culprit here? Any other ideas?
Thanks!
