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- Joined
- Feb 5, 2008
- Messages
- 32
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- Age
- 73
- Location
- Centralia, WA
- Vehicle Year
- 1983
- Make / Model
- Ford
- Engine Size
- 2.8 Durasparked, Stage 1 RV cam, block "0" decked, 350cfm Motorcraft 2150
- Transmission
- Manual
I recently bought a remanufactured Motorcraft 2150 (nonfeedback) for my Durasparked 2.8. Got in from a place in Phoenix called Carburetor Exchange for $179, with automatic choke even. Seemed like a good deal. The description of what they do in the rebuilding process seemed pretty thorough, even replacing the throttle shaft bushings. Since the carb that I was replacing was pretty well shot I figured it was worth the risk.
But when I put the reman on the truck it acted like it had a vacuum leak, i.e., I couldn't control the idle. I sprayed around the engine with carburetor cleaner and found a leak on the passenger side of the carb and it seemed to be around the throttle shaft. According to their policy, I packaged the carb back up and returned it for a replacement with a note explaining what I suspected to be the problem. About a week and a half later the "replacement" arrived. I was frosted! It was the exact same unit I returned. The only thing I could see they did was change some of the adjustments. I almost called them on the spot to give them a piece of my mind but as I was inspecting the carb I discovered something about the automatic choke setup that turned out to be the key to getting it to work properly.
Keep in mind, this is one of those automatic chokes that has both an electric heating element and a hot air heat tube fitting. My rig doesn't have a heat tube setup for the choke and I had always assumed that the heat tube was optional. I had heard that automatic chokes like this would work fine off the electric side alone, maybe having to compensate with an adjustment. Well, I was wrong, at least on this carb. For some reason I put my lips on the hot air tube fitting of the choke and blew. Lo and behold I felt air come out of a small hole in the underside of the carb. When I plugged that with my finger and blew, I felt air come out from a small opening in the plastic choke cap. There was my vacuum leak: the heat tube side of the auto choke! Of course, the heat tube fitting on the choke is very close to the throttle shaft so it originally fooled me. As I inspected the arrangement more closely I could see that one of the mounting legs of the choke housing had a small gasket between the mount and the carb body. Apparently the OEM application drew hot air through choke housing from the heat tube via manifold vacuum somehow without creaing a vacuum leak. Anyway, I plugged the small hole underneath the carb and now the 2.8 purrs like a kitten at idle.
I thought I'd share this with the Ranger community still utilizing carbs in case someone else was having a vacuum leak they could not figure out.
But when I put the reman on the truck it acted like it had a vacuum leak, i.e., I couldn't control the idle. I sprayed around the engine with carburetor cleaner and found a leak on the passenger side of the carb and it seemed to be around the throttle shaft. According to their policy, I packaged the carb back up and returned it for a replacement with a note explaining what I suspected to be the problem. About a week and a half later the "replacement" arrived. I was frosted! It was the exact same unit I returned. The only thing I could see they did was change some of the adjustments. I almost called them on the spot to give them a piece of my mind but as I was inspecting the carb I discovered something about the automatic choke setup that turned out to be the key to getting it to work properly.
Keep in mind, this is one of those automatic chokes that has both an electric heating element and a hot air heat tube fitting. My rig doesn't have a heat tube setup for the choke and I had always assumed that the heat tube was optional. I had heard that automatic chokes like this would work fine off the electric side alone, maybe having to compensate with an adjustment. Well, I was wrong, at least on this carb. For some reason I put my lips on the hot air tube fitting of the choke and blew. Lo and behold I felt air come out of a small hole in the underside of the carb. When I plugged that with my finger and blew, I felt air come out from a small opening in the plastic choke cap. There was my vacuum leak: the heat tube side of the auto choke! Of course, the heat tube fitting on the choke is very close to the throttle shaft so it originally fooled me. As I inspected the arrangement more closely I could see that one of the mounting legs of the choke housing had a small gasket between the mount and the carb body. Apparently the OEM application drew hot air through choke housing from the heat tube via manifold vacuum somehow without creaing a vacuum leak. Anyway, I plugged the small hole underneath the carb and now the 2.8 purrs like a kitten at idle.
I thought I'd share this with the Ranger community still utilizing carbs in case someone else was having a vacuum leak they could not figure out.
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