Post by Deleted on Jan 31, 2016 7:43:40 GMT -5
Ok gents, the Professor was getting antsy since there wasn't any activity lately on the forum...
So, the old jeep isn't enjoying life so much. I had it out yesterday...it drives, it'll cruise through mud and all, but it doesn't sound "just right" and it seems like it is lacking a touch of power. For instance, it felt like it struggled to climb the trailer ramps and I had to give her way more acceleration on the pedal.
Backstory:
I just replaced the gasket between the manifolds and the engine. I removed the carburetor and set it on the work bench before pulling the manifolds. I felt like all surfaces were readily cleaned before installing the gasket and bolting the manifold back in place.
The carb was put back in place, choke & throttle cables installed, and then primed. Upon ignition, she started relatively easily, but didn't sound well...or at least not how I remember it to sound. The RPMs were a bit high, so I double checked my throttle cable.
Fault #1 found: when installing the throttle line, my throttle stop screw (at the end of the cable) was a bit high on the cable and giving it gas. I readjusted that and it knocked the RPMs way down.
At this point, I thought I would follow through the basic tune up guide that I saw on Scout's forum.
Idle mixture screw and and the steel idle stop screw: check.
Hooked up vacuum gauge and dwell/tack
Started jeep
The idle RPMs still sounded high. The vacuum gauge held steady at 20. The dwell/tack read 600 on the 8 CYL dial. (The dial notes that for a 4 cylinder engine, double the 8 cylinder readings). So I'm looking at 1200 RPMs at idle. Wicked high.
I tried backing off the steel idle stop screw, which helped...a little.
The idle mix screw didn't do a whole lot except stall the engine.
On restart, I thought I would move over to the distributor. At this point, the vacuum gauge is reading 16/17, which is boarder line to late ignition timing.
At the distributor:
I tried retarding the timing. This immediately dropped the vacuum gauge to the 6-8 range: late valve timing or leak at intake manifold or heat riser.
Ok...I could buy into a leak at the intake since that was just off the jeep.
When I spun the distributor in the clockwise direction, the best spot I could get the vacuum needle to was back to that 16/17 area. If I went further, the jeep would begin to stall.
I checked the manifold bolts I could reach...I could tighten them approximately a gnats ass width. When the manifold was removed, I did not separate the intake from exhaust. I checked my points gap. It was a bit wide. After bringing it back to spec, the jeep ran and sounded much better, but still not right. 6 hours later, I started it and it sounded like it was regressing...I felt like I had to give it a bit more fuel to ensure it would keep going.
Alright gents, what's my next play? Search for an air leak? My other thought speculated sediment kicking up in my carb while it got knocked around on my work bench.
So, the old jeep isn't enjoying life so much. I had it out yesterday...it drives, it'll cruise through mud and all, but it doesn't sound "just right" and it seems like it is lacking a touch of power. For instance, it felt like it struggled to climb the trailer ramps and I had to give her way more acceleration on the pedal.
Backstory:
I just replaced the gasket between the manifolds and the engine. I removed the carburetor and set it on the work bench before pulling the manifolds. I felt like all surfaces were readily cleaned before installing the gasket and bolting the manifold back in place.
The carb was put back in place, choke & throttle cables installed, and then primed. Upon ignition, she started relatively easily, but didn't sound well...or at least not how I remember it to sound. The RPMs were a bit high, so I double checked my throttle cable.
Fault #1 found: when installing the throttle line, my throttle stop screw (at the end of the cable) was a bit high on the cable and giving it gas. I readjusted that and it knocked the RPMs way down.
At this point, I thought I would follow through the basic tune up guide that I saw on Scout's forum.
Idle mixture screw and and the steel idle stop screw: check.
Hooked up vacuum gauge and dwell/tack
Started jeep
The idle RPMs still sounded high. The vacuum gauge held steady at 20. The dwell/tack read 600 on the 8 CYL dial. (The dial notes that for a 4 cylinder engine, double the 8 cylinder readings). So I'm looking at 1200 RPMs at idle. Wicked high.
I tried backing off the steel idle stop screw, which helped...a little.
The idle mix screw didn't do a whole lot except stall the engine.
On restart, I thought I would move over to the distributor. At this point, the vacuum gauge is reading 16/17, which is boarder line to late ignition timing.
At the distributor:
I tried retarding the timing. This immediately dropped the vacuum gauge to the 6-8 range: late valve timing or leak at intake manifold or heat riser.
Ok...I could buy into a leak at the intake since that was just off the jeep.
When I spun the distributor in the clockwise direction, the best spot I could get the vacuum needle to was back to that 16/17 area. If I went further, the jeep would begin to stall.
I checked the manifold bolts I could reach...I could tighten them approximately a gnats ass width. When the manifold was removed, I did not separate the intake from exhaust. I checked my points gap. It was a bit wide. After bringing it back to spec, the jeep ran and sounded much better, but still not right. 6 hours later, I started it and it sounded like it was regressing...I felt like I had to give it a bit more fuel to ensure it would keep going.
Alright gents, what's my next play? Search for an air leak? My other thought speculated sediment kicking up in my carb while it got knocked around on my work bench.
