Man
New Member
- Joined
- Nov 27, 2020
- Messages
- 7
- Reaction score
- 0
- Points
- 1
- Location
- US
- Vehicle Year
- 1985
- Make / Model
- Ford Bronco II
- Engine Type
- 2.8 V6
- Transmission
- Manual
- 2WD / 4WD
- 4WD
HTG y'all,
I've got a BII with the 2.8 that's giving me some trouble. It's durasparked with some older Ford two barrel carb and distributor.
Here's the situation:
Idles rough, but can hold an idle down to 6-700 rpm (set it to ~9 cause its stick). Starts right up. Doesn't smoke. Doesn't leak. Accelerates alright for what it is. Doesn't heat past ~205 when driving. There is some exhaust tick.
When I pull the plug wire for cylinder 1 (passenger-front), rpm drops to about 6-7, but idles a LOT smoother.
Pulling the wire for 2, 3 there's no change in roughness or rpm.
Cleaned distributor out, it looks ok. New plugs, and swapped wires around. So I'm confident it's either compression or fuel. Gut feeling says fuel even though logic says compression.
Idiotically, plugs got mixed up so I don't know which ones came from which cylinders. What a headache.
Now, I was thinking maybe 2, 3 are misfiring due to a hg leak between them. This would keep the fluids clean and explains why idle rpm/roughness aren't affected. But does it explain why cyl 1 is causing the engine to run rough? Could it really run ok on just 4, 5, 6?
I'm also thinking, something could be up with the intake man/valves? Maybe cyl 1 intake valve is stuck open, 2,3, stuck closed? Could the intake just be blocked somehow preventing a-f mix from getting to 2,3 so too much goes to 1?
I can't imagine timing is off with gears, engine hasn't been taken apart as far as I know. Gears can't jump unless some teeth broke but I haven't seen much about that on here.
I know I should run a comp test to know for sure about hg, but before I go to HF and pick up another gauge (my tools are mia) what am I missing? Assuming its fuel (gut never lets me down in poker), what do I do?
Full disclosure, have to sell it soon (for work), but wouldn't feel right passing it on without fixing it.
I've got a BII with the 2.8 that's giving me some trouble. It's durasparked with some older Ford two barrel carb and distributor.
Here's the situation:
Idles rough, but can hold an idle down to 6-700 rpm (set it to ~9 cause its stick). Starts right up. Doesn't smoke. Doesn't leak. Accelerates alright for what it is. Doesn't heat past ~205 when driving. There is some exhaust tick.
When I pull the plug wire for cylinder 1 (passenger-front), rpm drops to about 6-7, but idles a LOT smoother.
Pulling the wire for 2, 3 there's no change in roughness or rpm.
Cleaned distributor out, it looks ok. New plugs, and swapped wires around. So I'm confident it's either compression or fuel. Gut feeling says fuel even though logic says compression.
Idiotically, plugs got mixed up so I don't know which ones came from which cylinders. What a headache.
Now, I was thinking maybe 2, 3 are misfiring due to a hg leak between them. This would keep the fluids clean and explains why idle rpm/roughness aren't affected. But does it explain why cyl 1 is causing the engine to run rough? Could it really run ok on just 4, 5, 6?
I'm also thinking, something could be up with the intake man/valves? Maybe cyl 1 intake valve is stuck open, 2,3, stuck closed? Could the intake just be blocked somehow preventing a-f mix from getting to 2,3 so too much goes to 1?
I can't imagine timing is off with gears, engine hasn't been taken apart as far as I know. Gears can't jump unless some teeth broke but I haven't seen much about that on here.
I know I should run a comp test to know for sure about hg, but before I go to HF and pick up another gauge (my tools are mia) what am I missing? Assuming its fuel (gut never lets me down in poker), what do I do?
Full disclosure, have to sell it soon (for work), but wouldn't feel right passing it on without fixing it.
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