Hey guys, looking for some suggestions from folks who have "been there, done that" with distributors/timing. Let me explain to you my issue but first some background. My buick 350-2 is a 1968, it runs pretty good, I just rebuilt the carb last month and it's been purring nicely (though I'll admit the idle is high at around 1400 rpms at idle). Other than the high idle, I've had little complaints with the way it cruises and the way it pulls when I punch it. I guess I got greedy, I have a problem with fixing things that are not broke. I purchased a Mr Gasket Advance Curve kit and thoroughly read Larry's "power timing" thread that everybody is familiar with. I actually read the whole thread twice which at 16+ pages, takes some time. I came to the conclusion that I was going to first find out what my timing was at idle, so I warmed up the car and checked it. It was higher than I could read on the indicator so I plugged the vaccum advance and there she sat, at around 15*'s, kinda jumpy but was close enough. I then took out the two factory springs and added the two lightest ones and reved up the engine and found that it appeard all of my timing was in at what appeared to be just under 30* (I have a conventional timing light so I did have to make the additional mark 1.75 inches clockwise from zero). This seemed fair enough so I turned off the engine and prepared the distributor so that I could turn it and adjust timing (something I've never done before). I take off the hold down clamp and bolt and I can't get the distributor to budge (a common issue I read). After some light coaxing with a rubber mallet and 12 inch drift, I get it to rotate both clockwise and counter clockwise but it's not easy, I actually still can't move it by hand. This is where it gets nasty. I dissasemble the distrubutor the best I can so that there is less to break, at this point I'm attempting to remove the distributor so I can clean it up and make it easier to turn so that I can make timing adjustments. I removed the springs, the weights, the points setup and the vaccum canister..... after looking everything over and cleaning up the vaccum canister and making sure it works I reassemble it all (possibly where my fault is). It seemed pretty straight fwd, I'm no rocket scientist but it's just a few screws here and there. Well I failed at being able to move the distributor by hand so I decided to just make small adjustments with the punch and hammer while the engine was off and then start it back up and see where I ended up. After some trial and error I managed to get all my timing in at 32* and I felt like that was good, I then took one of the light springs off and replaced it with a "medium" spring (one copper colored one and one silver). I read that this was a good combo. I also used the aftermarket weights... I stitched it all back up and took it for a test run. It started fine, sounded good, cruised fine, got out to my normal "stomping pad" and punched it....nothing. It sounds like it's choking and I feel as if the transmission kicks down to prepare for "warp speed" and then the engine doesnt come through for it. Stepping on it only boggs it down it seems.... there's the slight hesitation like it's going to take off and it feels like the transmission kicks down (as normal) but there's no go... it just chokes. Again, I know little about this and Larry's writeup was so well written I felt like I couldn't go wrong. If I had to guess, it feels like the engine is doing the opposite of "pinging".... does this mean it doesnt have enough timing? Any suggestions on what to check? I took it back home and tried to just put it all back to the way it was when I first started and it still did the same thing, with factory springs and weights, so I don't think that's the issue. Just for some further info, I didn't mess with the carb or tranny at all, just the distributor. This issue is only one day old so I still have some playing around to do with it before it's a problem, just wanted to see what you guys thought. I apprecite all input, thanks.
I agree that the idle does need to come down, this was the initial reason I rebuilt the carb. If that didn't slow the idle my next step was to adjust the timing and while I was at it, add the curve kit. It has idle this high since I got it and it's not stuck on the fast idle cam and the throttle is returning all the way.
You do know that there is a screw by where the throttle cable hooks up to the carb that is there to adjust idle speed,don't you? And I agree with smar,your idle is WAY to high to check initial timing,at 1,400 rpm I would think the centrifical weights would take it out to around 20 degrees or more depending on the springs. If you put the weak springs before you checked your initial and its only 15 degrees @ 1,400 rpm,I think your problem now is NOT enough timing. If your going to mess around with stuff like this you should invest in a timing light with dial back timing control. As far as using a hammer on the dis. DON'T do that,get some sort of spray oil like PB Blaster or similar to loosen up the gunk that has your dis. frozen. (hammers are for carpenters,not tune-ups)GL Derek
You are referring to the one that touches the fast idle cam right? I've had it all the way out and it doesnt lower the idle. I actually have it set so that it barely touches the cam at the normal position, so that it only idles up whenever the choke is involved and the cam is at the lobe. I figured a plan-jane timing light would be sufficient since it's pretty much a tool I may use once or twice ever, I assume folks survived on them just fine at one time or another. I soaked it in PB blaster overnight, hopefully that will help with getting it loose. I'm going to put the stiffer springs in it tonight and see if I can get any results by adding in some timing. Thanks
I don't have a carb in front of me,but there is another screw that adjusts your regular idle,do a internet search on your carb and maybe you'll be able to find exactly where it is? The screw I'm talking about changes the angle of the throttle plate opening when there is no pressure on the gas peddle. I see in your first post you have a 2bbl,I have one in the garage I can look at to see where the idle adjustment screw is,later when I get home. Derek
The screw to adjust your idle speed is on the driver's side, and that is the same screw that contacts the fast idle cam. That is the way it is on the Rochester 2V, unlike the Q-jet. You must make sure that the fast idle cam is rotated so that it is on the lowest step. Then back the idle speed screw until the idle speed comes down. If it doesn't, you may have a vacuum leak, or other mechanical problem with the carburetor. Now for the distributor. The stock distributor for the 350 in 1968 is 1111330. Have a look at the part number. It is on the circumference of the distributor right under where the lower edge of the cap sits. If that is the distributor you have, it has a maximum mechanical advance of somewhere between 26 and 30*. That means your initial advance will be between 2* and 6* to get a total of 32* without the vacuum advance. You need to get the idle speed down to about 800 RPM. You also need to spray some penetrant on that distributor until it loosens up. Hitting it with a drift and hammer will damage parts. There is probably some corrosion built up. It needs to move easily as a small movement can make a big difference in timing. If you use the lightest springs, you should rev the engine until your 30* mark stops moving up. Then move the distributor with the engine at that RPM so that your 30* mark lines up with the 2* mark on the timing tab. That will be 32* total. If you do have that 1111330 distributor, put the stock springs back in, and with the idle speed at 800 or lower, your initial should be between 2 and 6*.
Ok,I went out and looked at the 2v carb I have in the garage,and like smar and Larry said that one screw adjusts both your initial idle and your fast idle. It looks like your choke may be sticking open if you don't have a vacuum leak. The choke plate should be straight up and down when the engine is warmed up,if it isn't the idle screw will still be on the fast idle cam. The cam looks to have various steps on it for different cold weather conditions for different choke positions,and if it is idling @ 1,400 then it is probably on the coldest setting with the choke almost all the way closed. This is assuming there are no vacuum leaks to make it idle up. To check for a vacuum leak you can use a vacuum gage to verify a leak or spray some carb cleaner around the base of the carb to find the leak. If the idle goes up when your spraying the carb cleaner around the base of the carb you have found your leak. If it stays the same,try spraying the carb cleaner where the intake is bolted to the heads,because it may be a intake gasket failure that has the vacuum leak. Also the throttle shaft area is a good place to check as well. Don't go to crazy with the carb cleaner though,a small amount should tell you what you need to know,not so much that it puddles,but enough to work its way in if there is a leak. Check the choke first.GL Derek
Hey guys, I'm back with an update. I didn't mess with timing tonight because I was short on time. I checked a few things though, Larry the number on my distributor is 1111474 8B8 so apparently it's not stock. Until tonight I've been checking RPM with my Matco multimeter, (saving for a good tach) it's read ~1400 consistently at idle, we'll I borrowed a spare tach and it confirms that rpm is 1400. Vacuum was tested by pulling the line from the distributor advance while in park...this gave a reading of 17in-hg, let me know if this was wrong (I figure the idle drop by removing from vacuum canister could lower vacuum). I double checked the fast idle cam on the carb and it's set properly. I'll get more info tomorrow. Thanks
First, you cannot even start to check timing without checking and adjusting the dwell to specs (30*). Changing dwell changes timing. Adjust the dwell. Second, if this engine is stock with a stock cam, your vacuum is low. I would expect your vacuum at 1400 RPM to be higher than it would be at an 800 RPM idle in Park/Neutral. The engine has no load on it, so vacuum will be higher just off idle. My 470 engine idles at 900 RPM at 14-15" of vacuum with the roller cam. If I open the throttle to 1500 RPM, and hold it steady, the vacuum goes up to 20". Your bone stock engine should idle at 800 RPM in Park/Neutral with no less than 20". Opening the throttle to 1400 RPM, and the vacuum should be steady at 20". Something is wrong. Either your timing is way off, or you have a vacuum leak. I don't have any information on that distributor, 1111474. You can still power time it to 32* and let the initial advance fall where it will.
Thanks guys, I will do this tonight, back to the basics. I am guilty of trying to power time to fix the idle issue, I knew I had to get into it anyway and wasnt quite sure what was causing the high idle.... I assumed it was connected with the timing and figured I'd eventually get it figured out. My distributor is from a 1969 350, from what I found on google. I'll see if I can get it back to idle smooth at 800 rpm and go from there. I'll report back tonight on my initial dwell reading and my new vacuum readings from the secondary location. Thanks again
I love these type of threads. A lot to be learned and basics revisited. My only comment is this: One change at a time. It's very easy to make 3 or 4 moves ( springs, timing, dwell, etc ) and get lost. Ask me how I know!
Can you post a picture of your carburetor and linkage set up? Like they have said, take off the fast idle dashpot, and adjust idle using the main idle adjustment screw, and the air/idle adjustment screws. If I have a 2 bbl in my shop, I will post some pictures for you.
My Steven Dove book shows 1111938 as the 350-2 carburetor. It has 30-34* of mechanical advance Rotate that picture:laugh:
If you're still having problems this weekend, drive it over to the house and we'll work on it. Plus, you have an intake sitting in my attic :laugh:
Picture confirms it. Take that dash pot off and toss it away. Not needed, not connected to anything, and keeping you from being able to adjust your idle speed properly.
