Tolkmod Posted July 17, 2015 Report Share Posted July 17, 2015 That is a good question. Maybe it's not carb related at all. Maybe the weights in the distributor are sticking...? And the high idle helps keep them "afloat". How would i be able to test this theory? Quote Link to comment
Stoffregen Motorsports Posted July 18, 2015 Report Share Posted July 18, 2015 How would i be able to test this theory? You could test it with a vacuum gauge and hand held vacuum pump, but it's probably easier to pull the distributor cap and move the distributor cam back and forth. It should have spring tension pulling it back. It should be smooth and not notchy. It should not move up and down (vertically) too much. Maybe .015"-.020" vertical play. If it does feel off, you will need to pull the distributor plate and investigate. Simply lubricating the weight pivots could fix the problem, but not likely, Sandpaper, a small file and possibly a new distributor cam can refurbish the mechanical advance in a distributor. Quote Link to comment
Tolkmod Posted July 18, 2015 Report Share Posted July 18, 2015 Okay, I'll see if i can gather up the courage to check those things out. Thanks for the heads up. Quote Link to comment
datzenmike Posted July 18, 2015 Report Share Posted July 18, 2015 The vacuum advance is not the same as the mechanical advance. You can't test mechanical advance with a vacuum pump. The mechanical advance uses spinning weights held by springs. The faster it spins the more centrifugal force moves the weights out and the cam turns the plate CCW and advances the timing. Mechanical advance is RPM dependent. Vacuum advance is a separate diaphragm that add advance with light throttle and removes advance with heavy throttle. Vacuum advance is load dependent. 1 Quote Link to comment
Stoffregen Motorsports Posted July 18, 2015 Report Share Posted July 18, 2015 You're right. I wasn't thinking. The visual inspection will be the same though. Quote Link to comment
datzenmike Posted July 18, 2015 Report Share Posted July 18, 2015 (it's Friday.. :lol: ) Quote Link to comment
Stoffregen Motorsports Posted July 18, 2015 Report Share Posted July 18, 2015 I am self employed. I can't keep track of days... 1 Quote Link to comment
datzenmike Posted July 18, 2015 Report Share Posted July 18, 2015 1/ Friday 2/ Self employed 1 Quote Link to comment
Tolkmod Posted July 20, 2015 Report Share Posted July 20, 2015 lol @ the both of ya So i pulled off my dist cap and checked the spring. It's firm (took a bit more effort to move it than i expected) but it was smooth when I moved it. Felt almost no play going up or down on it either. So if that's the extent of the test I don't think it's the distributor. Question, will the voltage regulator affect any of this? Also, I read in a post that sometimes the exhaust manifold over heats the carb, and makes it run clunky, is that true or is it just someone blowing out hot air? (haha :rofl: like my pun there?) I'm guessing that if that is a problem, that I'd have to pretty much remove the carb and everything around it just to get it off and have it wrapped or insulated in some way. Quote Link to comment
datzenmike Posted July 20, 2015 Report Share Posted July 20, 2015 There is a hot idle compensator inside the air filter housing. (another good reason for not replacing it with some after market crap)It relieves an over rich condition caused by the thinner hot air by opening two closed air bleeds to the intake to lean the mixture. One opens at 140- 160F and the other at 160-195F. Voltage regulator will sometimes reduce idle speed a hundred RPMs after start up as it charges the battery back up. Quote Link to comment
Tolkmod Posted July 20, 2015 Report Share Posted July 20, 2015 Is there a way to test to see if its working properly? I ordered a voltage regulator a few days ago so waiting for it to show up. Hopefully that'll fix my alt issue as well as the weird idle, but we'll see. Quote Link to comment
datzenmike Posted July 20, 2015 Report Share Posted July 20, 2015 The voltage regulator shouldn't affect the idle. Heavy charge rate at idle is only barely noticeable and does not affect the running. Quote Link to comment
Tolkmod Posted July 27, 2015 Report Share Posted July 27, 2015 ok... so my little B210 sure is throwing me some curve balls here lately lol I got my new voltage regulator installed and started her up. Voltage went straight to 14.5 - 15v while warming her up. Soon as I got to a normal temp range I let off the gas and the idle... shockingly... dropped to 900 rpm, it never does this!!! Then the really freaky thing happened, the voltage stayed at 14.5 - 15v at that idle. This shocked me most of all because I haven't been able to get above 12v even at 1300 rpm. So go figure... So, I revved it up a few times and then held it steady at 2k RPM and bam... my voltage jumped to almost 16v, no idea why it just jumped up. Then, when i let go, it dropped back down to 900 rpm and then started doing this jumping thing where it would just bounce very consistently between 12v and 16v, almost like someone was slowly pressing the gas, then letting it go in a very "ocean waves" like manner (sorry from the O.C. so i don't know how else to describe it lol) Anyways... it was freaking me out. So i looked at my old voltage regulator and unscrewed the cap (can't do that on the new one for some reason, guessing newer smaller parts, no access etc. It's riveted on where the screws on the old one are currently) and opened it up. I found that there were two point type devices inside that I can only assume act as switches to regulate the output of the alternator. One of them though, looked like it was bent slightly, at an angle that the points wouldn't have touched either side of the contacts. The metal that held the points touched, but not the points themselves. So I fiddled with it for a bit and was able to angle it back to where the points touched properly. I hooked it back up to test it, car wouldn't hold an idle. So, my only course of action is to keep the current regulator in, and wait till i can afford to upgrade/replace my alternator. I'm to scared to even take it out to get it tested now, I don't want to mess with it until i at least have the money to replace it if needed. Quote Link to comment
datzenmike Posted July 27, 2015 Report Share Posted July 27, 2015 Be absolutely sure the battery posts and cables are tight and clean. The battery also helps regulate any voltage spikes. Quote Link to comment
Tolkmod Posted July 27, 2015 Report Share Posted July 27, 2015 Yup, not only did I do that, but I've replaced all the battery terminals, cables and clamps. The original wire coming off of the alternator power side was badly oxidized and brittle, so I completely replaced that one as well. 1 Quote Link to comment
Stoffregen Motorsports Posted July 27, 2015 Report Share Posted July 27, 2015 On a sysytem that uses a voltage regulator and alternator separately, it is wise to replace both of them at the same time. If you only replace the one, the other coul;d take out the new parts. This sounds like it may be the case here. Those old voltage regulators are really cool. DO NOT throw it away. The new ones are usually solid state and are not adjustable or rebuildable or fixable in an emergency. The old points type are all of those. You can adjust the current, you can rebuild them (I know someone who can do them) and they can be rigged to get you home in a pinch. They don'y make the old style anymore. This alternator guy I have up here near me does a Datsun alternator with regulator as a unit. I think he gets $40 for the mod. Quote Link to comment
Tolkmod Posted July 28, 2015 Report Share Posted July 28, 2015 This alternator guy I have up here near me does a Datsun alternator with regulator as a unit. I think he gets $40 for the mod. You have PM Quote Link to comment
Stoffregen Motorsports Posted July 28, 2015 Report Share Posted July 28, 2015 Got it. Quote Link to comment
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