Gary Lewis Posted December 19, 2019 Share Posted December 19, 2019 I lied... 🙁 I found it in the back corner of the bottom drawer. Jim - Some un-named person needs an apology? Cory - I hope the start-up goes very well. I'm betting it will with all the layers of the onion you've removed. Time for a Bloomin' Onion! Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 19, 2019 Share Posted December 19, 2019 Cory, just get a carb adjusting flex tool. It's not hard to reach the base flange of a Holley -under the stock air cleaner- with one. Mine was a hex handle that slid along a spring, with a slot bit on one end and a hex on the other. It was also used for adjusting GM points distributors. Iirc, I got it from one of those spinning racks of KD tools. And posted a picture, back on FTE. Jim, if that is a "normal" Holley, not the 4180 emission style, the mixture screws should be on the side of the primary metering block. He may still need the tool to reach them with the air cleaner installed though. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 19, 2019 Share Posted December 19, 2019 Jim, if that is a "normal" Holley, not the 4180 emission style, the mixture screws should be on the side of the primary metering block. He may still need the tool to reach them with the air cleaner installed though. 4180?? With the mixture screws in the base flange. 4160 does have the idle jets in the metering block. Link to comment Share on other sites More sharing options...
Rembrant Posted December 21, 2019 Author Share Posted December 21, 2019 Cory - I hope the start-up goes very well. I'm betting it will with all the layers of the onion you've removed. Time for a Bloomin' Onion! Ok, so I stuck the distributor back in. Once the gas flowed back up to the carb it fired right up. Up to temp now, here are the readings: Base timing is at 10 degrees BTDC. RPM is 1100. Engine vacuum is 18.5" AFR is approx 11.2 So what do I start adjusting first? Idle speed, idle mix, or timing? Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 21, 2019 Share Posted December 21, 2019 Cory - I hope the start-up goes very well. I'm betting it will with all the layers of the onion you've removed. Time for a Bloomin' Onion! Ok, so I stuck the distributor back in. Once the gas flowed back up to the carb it fired right up. Up to temp now, here are the readings: Base timing is at 10 degrees BTDC. RPM is 1100. Engine vacuum is 18.5" AFR is approx 11.2 So what do I start adjusting first? Idle speed, idle mix, or timing? Bring the idle down first. Then adjust the idle mix and readjust the RPM. Link to comment Share on other sites More sharing options...
Rembrant Posted December 21, 2019 Author Share Posted December 21, 2019 Bring the idle down first. Then adjust the idle mix and readjust the RPM. Ok, that was all very easy. The 1100 RPM idle was due to the choke plate linkage being hung up on the carb spacer, because I had it positioned wrong. Once that was fixed, idle dropped to 600 RPM. I've played around with it for a bit, and got the AFR at 14.5 at an idle of 750 RPM. Best vacuum I can get in this scenario is 17.5". Question though... The idle mix screws. I assume they need to be adjusted equally left and right? Each has to be the same number of turns? I'll have to play with it some more. The 14.5 AFR was with the right hand idle mix screw at 3/4 turn out, and the left hand screw at 1.0 full turn out. Once I evened them both up to 1.0 turns, the AFR dropped to 13.2-ish. I'm on the right path at least. It's idling nice and smooth. Can't drive it until the roads clear up though, bugger. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 21, 2019 Share Posted December 21, 2019 Bring the idle down first. Then adjust the idle mix and readjust the RPM. Ok, that was all very easy. The 1100 RPM idle was due to the choke plate linkage being hung up on the carb spacer, because I had it positioned wrong. Once that was fixed, idle dropped to 600 RPM. I've played around with it for a bit, and got the AFR at 14.5 at an idle of 750 RPM. Best vacuum I can get in this scenario is 17.5". Question though... The idle mix screws. I assume they need to be adjusted equally left and right? Each has to be the same number of turns? I'll have to play with it some more. The 14.5 AFR was with the right hand idle mix screw at 3/4 turn out, and the left hand screw at 1.0 full turn out. Once I evened them both up to 1.0 turns, the AFR dropped to 13.2-ish. I'm on the right path at least. It's idling nice and smooth. Can't drive it until the roads clear up though, bugger. Where is your O2 sensor located? Anyway, it isn’t necessary to adjust the idle screws the same. Adjust for best idle and don’t sweat the AFR. Link to comment Share on other sites More sharing options...
Rembrant Posted December 22, 2019 Author Share Posted December 22, 2019 Where is your O2 sensor located? Anyway, it isn’t necessary to adjust the idle screws the same. Adjust for best idle and don’t sweat the AFR. O2 sensor is monitoring the right hand bank of the 302, and it's pretty close to the engine...probably a bit too close, but it works fine. I'm noticing that the AFR reading is much smoother now that I have the vacuum leak fixed...it was on that same bank, so the AFR was swinging quite a bit previously. We had to run out this evening, so I didn't do much more with it today. I'll spend some time on it tomorrow and see if I can get it dialed in a little better. I can tell that it's already running much better than it was before. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 22, 2019 Share Posted December 22, 2019 Where is your O2 sensor located? Anyway, it isn’t necessary to adjust the idle screws the same. Adjust for best idle and don’t sweat the AFR. O2 sensor is monitoring the right hand bank of the 302, and it's pretty close to the engine...probably a bit too close, but it works fine. I'm noticing that the AFR reading is much smoother now that I have the vacuum leak fixed...it was on that same bank, so the AFR was swinging quite a bit previously. We had to run out this evening, so I didn't do much more with it today. I'll spend some time on it tomorrow and see if I can get it dialed in a little better. I can tell that it's already running much better than it was before. With the O2 sensor on one side you'll get a false reading of the overall AFR at idle 'cause you can easily create an imbalance via the idle screws. So I'd just go for max vacuum or RPM and not worry 'bout the AFR. In any event, you've turned the corner on the problems. Hope you get to take it out this winter to test it out. Link to comment Share on other sites More sharing options...
Rembrant Posted December 25, 2019 Author Share Posted December 25, 2019 In any event, you've turned the corner on the problems. Hope you get to take it out this winter to test it out. So I got the old Bull out for a Christmas Day shakedown run! It was -3C out..or about 26F, but the roads were nice and dry. I made one final little tweak of the idle mix screws, and it's running MUCH better now! The big difference is between 1500-2000 RPM where it never really ran well previously. I can now cruise along at 1500 RPM in 4th gear and accelerate smoothly to 2000, which was never the case before. The AFR seems to be really good as well. Cruising along at light throttle at 2000 RPM, the gauge is reading 14.5-14.7 pretty consistently. I'm a happy guy today. Merry Christmas guys, and thank for all the assistance in getting the old Bull running better;). Link to comment Share on other sites More sharing options...
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