October 25, 201213 yr Pump the pedal once, start it, it fires fine but just burns the gas from the initial pump. Dont touch pedal, start again, burns a little bit of gas, dies. 3rd time, dont touch gas, start it...perfect. The choke is set properly. Even if I go way rich on it, it doesnt make a difference. What gives?
October 25, 201213 yr Author Electric, brand new. Old one did the same thing which is why I replaced it. Choke is set properly.
October 25, 201213 yr it might be set properly, but is it working? Also, have you checked the timing?
October 25, 201213 yr Electric, brand new. Old one did the same thing which is why I replaced it. Choke is set properly. How about the choke pull-off?
October 25, 201213 yr Author How about the choke pull-off? Explain. The choke opens fully and closes fully until you start it. Once you start it, it opens about 1/8".
October 25, 201213 yr Try without the initial pedal pump and see if it starts. I had a 32/36 on my engine with an electric choke and when the engine was turned off some the gas in the fuel bowl would drain into the manifold ( I have no Idea why) So if I pumped the pedal when I started the car in the morning it would flood really badly. I would just start without touching the gas and let the engine do the rest. I have since replaced that carby with another brand of weber an ADM34. As good as the webers are they can be fickle in the mornings. TOONGA
October 26, 201213 yr Author I generally just tap it to set the choke and thats it. You are right, they flood fast on cold starts.
October 26, 201213 yr Mine doesnt. It does flood a bit on hot starts though, if you touch the throttle at all.
October 26, 201213 yr Author Oh yeah, terrible on hot starts. Anytime to hit the throttle more than once, you're screwed.
October 26, 201213 yr If it is THAT hard to start hot for you then you are simply running too rich. Have you done the proper weber carb tuning procedure?
October 26, 201213 yr Do you know what jets you have? What are your idle mixture and idle speed screws set at?
October 26, 201213 yr Author Do you know what jets you have? What are your idle mixture and idle speed screws set at? Jets are what Weber tells me I should have 160/170 if I remember correctly. I might be wrong, but they are the correct ones according to my elevation. Mix is like 1.75 turns out. Fast idle probably 1500, low idle 1000.
October 26, 201213 yr ive heard webers are finicky on pressure, might want to check the incoming fuel pressure just in case. at least get a reading before you start changing settings so you know where your at.
October 27, 201213 yr Mix is like 1.75 turns out. Fast idle probably 1500, low idle 1000. Your low idle is kind of high. What is your primary idle jet size? Weber tends to send out jetting on the rich side so people don't damage pistons and such by running lean. How did you verify how many turns your idle speed screw has been turned after it touches the throttle lever? The Holley low pressure regulator is the most commonly recommended unit for these carbs ~$40. Easily ordered online. You can also get a fitting from a Hitachi carb that has the fuel return line, which can help a little with bowl pressure.
October 27, 201213 yr Author I dont like low idles. It shouldnt make a difference though. Not sure I understand your question about the idle screw. You dont mean mix screw, do you? 140/140 mains 170/160 air correctors 50 idle jets
October 27, 201213 yr Your idle and primary jets look good. I had the exact same issues with my weber and never did get to the bottom of it. Hot starts were hard and very very cold starts would do the same thing you just said. I just learned to live with it unfortunately. I learned to pump the gas 5-7 times when it was really cold (under freezing). If i did that it would usually start up and stay running on its own until it warmed up a bit. My hot start issue was due to fuel continuing to drip past when i shut the car off. You might want to check into that. It was never a big enough issue for me to try to fix it.
October 27, 201213 yr Author It just the first start of the day. 2x it will die, 3rd time it stays running and never an issue after that. If I could get the choke plates to stay fully closed once it starts, I think it might work. There has to be a way to adjust it I would think. This has nothing to do with the metallic spring adjustment, that closes it tight...til it starts.
October 27, 201213 yr Not sure I understand your question about the idle screw. If the idle speed screw is turned in more than 1.5 turns after it makes contact with the throttle lever, it exposes the enriching progression holes in the throttle bore. Since the throttle lever is stamped, there is typically a small ridge of metal along the center of the edge of the lever, so the screw can contact the lever before it looks like it. I slide a piece of paper between the screw and lever to determine when contact is made. This may not be your problem, but if you have the mixture screw set at 1.75 and your curb idle is 1000 rpm, then you should probably check to make sure your idle speed screw isn't turned in too far. I would probably put a 45 primary idle jet in to try to get the settings closer to design spec.
October 27, 201213 yr Author OK, I'll lower the idle for now and check. Is a jet a jet or is it Weber specific? Tailpipe is always full of soot, never has it been clean.
October 27, 201213 yr OK, I'll lower the idle for now and check. Is a jet a jet or is it Weber specific? They are Weber specific and they're are two kinds: large and small. You will want a small one, just look for the ones under DGV or DGEV. The nice thing about the idle jets on a Weber is that they are on the outside of the carb. You just have to unscrew the hold-down screw near the choke assembly to swap them out.
October 28, 201213 yr Explain. The choke opens fully and closes fully until you start it. Once you start it, it opens about 1/8". The choke pull off is a vacuum diaphram located next to the choke coil. It opens the choke a certain amount once the motor starts. Don`t recall the correct spec offhand,but,1/8" opening sounds ballpark. You can move the choke by hand w/the air cleaner off/engine freshly cold started to see if it needs more/less choke. IIRC,Weber choke pull off is adjusted by bending a tang inside the choke cover. Solution to your starting problem may be as simple as pumping the gas once or twice before starting.I have 2 electric choke equipped non subes that require this.Colder weather needs an extra pump or 12. Could simply be the fast idle screw is set too low as well.1500 seems too low to me.I`d go 2000. Low speed idle screw setting will have no effect on cold starts.1000 is a little high though. Water chokes resist hot start flooding better.Easy to swap. Edited October 28, 201213 yr by naru
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