SherpaPilot
Jedi Hopeful
Offline
I have a 72 TR6 that I have owned for 32 years. Over the many years of wrenching on this car, I thought I had a pretty good feel for knowing what to do when problems arose. During the winter, I purchased a complete rebuild kit for both Stromberg CD175s. Taking my time and following several references, I cleaned, rebuilt and reassembled both carburetors on the car. Adjusting these guys was quite a chore and now 4 months of occasional work has produced a fair result but not without nagging problems. I continue to have an erratic idle. I checked and adjusted the valves, installed a new distributor cap, rotor and wires. Replaced the entire fuel line from the tank to the carbs to include a new filter. The carbs were set up IAW all the reading material I could get my hands on. The linkage was checked and rechecked. I installed a secondary return spring on the throttle return. Vacuum advance was plugged and timing set for 32 degrees BTDC. As far as adjusting fuel/air mixture, I could not get the air valves to perform as the books recommend, you know lift a little not to exceed 1/4 see it it accelerates or dies. Both carbs acted as if they were too lean. I am now adjusted 1.75 turns to the rich side. Overall the car runs great and acceleration is super. The only problem I cannot solve is the erratic idle. Once set for 850-900, it seems ok,, but as soon as the engine is loaded up on the road, it comes back with an idle range of 500 to 1200 rpm. What is going on here? Both temperature compensators checked and installed and both idle trim screws set to 1 turn counter-clockwise. I also tried the trim screws fully closed. Does anyone have any experience in fixing an erratic idle? As always, thanks for any input you can offer. Maybe I need to invest in a colortune. I forgot to mention that manifold vacuum at idle is 17 psi.
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