Weber 44 IDF Question |
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Weber 44 IDF Question |
orbit398 |
Nov 1 2016, 09:57 AM
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#1
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Member Group: Members Posts: 139 Joined: 29-April 15 From: League city, Texas Member No.: 18,681 Region Association: Southwest Region |
Just looking to see if someone can help pin point an issue I am having – assume it’s a carb issue.
Here is what I have: 2.0 liter with flat top pistons (euro style), has ~160 psi on all cylinders, carb cam, bursch exhaust, dual Weber 44 IDF carb set up, idle jet = 55, main jet = 145, F11 emulsion tube, 200 air correction. Carbs are synced and pull the same at idle as well as about 1500. I live in Houston (sea level). I have read and followed several write-ups on tuning the Weber carbs. Overall, the car runs great above about 2200 rpm. It idles excellent. Issue: Still getting the occasional popping. More importantly, while under easy acceleration (throttle slightly opened/just limping along in traffic) ~around 2000/2200 rpm, the engine seems to be missing or it shutters. If I open the throttle just a bit more, it disappears and runs great. I cannot replicate this by just revving the motor up in neutral; does this only under a load?? What could be the issue here? I plan to recheck synchronization/insure carbs pulling equally, spray carb cleaner/starter fluid to check for air leaks, try to ensure butterflies are opening equally. Just puzzled at what it could be. |
stugray |
Nov 2 2016, 06:48 PM
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#2
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Advanced Member Group: Members Posts: 3,825 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
My latest 2 "carb problems":
1 - Using pump gas with ethanol will clog your idle jets & passages quickly with a white chalky substance. Use ethanol free gas or add Stabil. 2 - My accel pumps were not pumping the same amount on each side. I used the lid from a hypodermic needle attached to the end of a wire to stick down in the barrel of the carb when I actuated through a full open cycle. I used this method to measure how much fuel came out with a full pump. My two sides were different by a factor of ~5:1. I replaced the pump diaphragms and they then pumped the same amount. Car ran much better and no longer had the same "flat spot" when stepping on the throttle. EGTs and AFR gauges really help a lot. |
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