Volks: After replacing the temp sensor failed to cure the fuel loading problem on my 84 GL I took it to a VW mechanic who told me that I needed a new AFM. As I didn't have the money at that time, I took the van home. I read the AFM posts, and worked on it today.I cleaned the contacts, and repositioned the pointer so it glided on fresh track. Before reinstalling, I got out the OHM meter and Bentley, and did some tests. On pins 3 & 4, I had 560 OHMs, exactly as Bentley said I should. On 2 & 3 however Bentley didn't say what the change in OHMs should be across the arc, only that it should change. My results were interesting. With the throttle closed, I had the same 560 OHMs that I had across 3 & 4. A slight opening of the throttle, (about 1/8 inch movement of the pointer) shot this up to 1150 OHMs. It stayed there until the throttle was about 90% open then dropped, again over about 1/8 inch of pointer travel, to 250 OHMs. I don't know whether resistance is supposed to increase or decrease as the pointer moves, but in either case, I would have expected consistency. The fact that it does both suggests to me that the mechanic was indeed correct, and my AFM is shot. Is this a correct assumption based on this data? Anything else I can try? Or is this normal? Bentley could certainly have been more descriptive on this one. Any help will be appreciated. TIA John Flaherty Standish, ME '84 GL '74 SB |
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