At my witts end!

[Guest]

Hey everyone. This it gonna be lengthy, as I hope to give details on steps and trials taken.<P>Okay, the summed up version first. For awhile now my engine has had a knocking at idle, and pinging under acceleration (getting on the highway for example). No matter what I've tried, nothing helps. I used logic and tonight toned down "everything" and it actually got worse!<P>So, from the start of what I remember. I'm unsure 'when' it started. The pinging seems to start around the same time I replaced my starter. The knocking, hell if I remember when.<P>I let it go for a short while as it wasn't totally consistent (the knock that is).<P>The car sat for the month of June while I tried to get time in on the stereo. It was started once a week.<P>After I did that and cleaned everything up, it was ready to roll. Then these sounds became more and more apparent and I decided to fix it.<P>This brings me to yesterday. Vac gauge, timing light, engine analyzer all hooked up I went at it. The timing was around 14-15, idle mix all set, idle speed was up a bit. I brought everything back to spec, tightened carb base bolts and airhorn screws as well. The problem persisted.<P>Tonight I redid everything, only this time reducing the settings. Timing to ~8, idle at specs, carb mix readjusted. Took it for the test drive and not only had the performance gone to hell, the pinging was much worse and it still knocks! More on the test drive below.<P>Something observed while messing with the idle mix and idle speed was when I turned everything in and back out 1 1/2 turns, started car and jacked up the idle speed, the knocking was real bad, even as I increased the idle speed. Adjusting the mix helped.<P>I then got a random thought to pull the distrib cap, the outside vac advance screw was loose and jarring around in there. I fixed it and everything still persists! (that was done before the test drive)<P>Testing! Consisted of road & highway. Road/Street tests were from 40>WOT, 0-WOT, 0-part throttle. The first gave no problems, the second pitched a fit a little, and the third pitched a tantrum! I did variations on the above with the same results. Highway tests were 0>30>70 (entering highway), 50>80+(WOT), and passing. First test, pitched a sizable fit, second was fine as was the third(overall, it did fit a little sometimes).<P>As a nice straight road, pure acceleration & speed test, was 20>WOT(until around 90) which yielded no problems.<P>The knocking on idle. Start car, engine knocks. Drop into R or D, problem goes away, toss to P or N and it knocks a bit. I just don't get it.<P>I've tried idle speeds from 800-1100 in park, timing from ~8-15, and different rich and lean mix conditions. Nothing seems to work.<P>I pulled #1 spark plug, it shows a HOT condition. These are R44TS that I put in no more then 3000 miles ago to replace the R45TS's which shows the same HOT condition.<P>I haven't "decoked" the engine as I thought the 1200 mile trip I took would be good enough. Plus I have valve train noise, probably just a lifter or rocker but don't want to push my luck.<P>The first fillup after the June sit was 89 octane, I let it get half down and filled with 91 (plus 2 extra gallons). This obviously didn't make any difference.<P>I have a full pertronix setup now, with the new II series coming from Alan. Also have a 4bbl setup which I can swap. An odds side note, today after all my troubles, when I pulled back into the driveway I noticed a fresh spot of oil on the driveway, roughly a foot in diameter. When it sat in June, the same thing happened, on a much larger scale, about 1.5ft wide, 3ft long. It took almost a quart of oil then. I do have a rear main leak, least that's what the mechanic said awhile back. I dunno if that explains anything, but thought I'd mention it.<P>Well, I hope the above makes sense and someone is able to help me. I feel like I'm trying to debug 10,000 lines of programming code and have had 2 hours sleep in the last 48hrs.<P>Great Thanks to Everyone!<P>-Scott

[66400]

You might check the flex plate/flywheel, if one is loose or cracked the do make a knocking sound. Henry.

[BuickNut]

Sorry to hear of your problems. What milage does the car have ? I've got a high milage vehicle (155 kmiles...) which I know needs a new timing chain & distributor - no matter what I do to the settings, even when set to stock - it won't run or idle correctly though the it has all new tune up parts, carb rebuild, etc.. What shape is your distributor in besides what you outlined ? Was the problem there before you swapped out your stock ignition system ? Is the engine high performance or did you rebuild to higher performance than stock ? Is this the same gas station your getting your gas from ?

[old-tank]

Scott<BR>Just turn up your stereo! Some other things to consider: for the knock check your engine/trans mounts and be sure no exhaust or other engine components are hitting the frame or body; for the pinging try a known good distibutor or get yours recurved or at least check the centrifugal springs and advance weights. try driving without the vacuum advance connected...this will not affect full throttle performance or pinging at full throttle but should eliminate the part throttle pinging. If this stops the part throttle pinging consider an adjustable vacuum advance.<BR>Willie

[Guest]

Thanks Willie<P>I think if I turn up those Eclipes that loud I'll shatter my rear window tho. <P>Today I went out and purchased two sets of ACDelco plugs. Yes, two sets. One R44TS set and a R43TS set. I burned up R45's and now these R44's, so I figure I've gotta get cool enough sometime.. Tomorrow I plan on putting in the R43's and seeing what happens. I would have tonight, but it takes a good 2+ hours to change the right side. <P>I will indeed check for components hitting frame or body, as well as run with the vac advance disconnected. I have no spare distributor to test with, so if the vac thing works, I'll either (depending on price difference), buy a new distrib or adjustable vac advance.<P>How do I "test" the springs and weights?<P>TIA!<P>-Scott

[Guest]

Henry: When I replaced my starter, I checked everything over. No probs seen outside of some leaks that I could tell.<P>BuickNut: Mileage is I believe 98k (maybe less). I had problems before I swaped the pertronix in, don't we all? The distributor I believe just needs a new bushing at the bottom from what someone here told me awhile back. It also needs a new o-ring seal. Both of which I'll replace when installing the Ignitor II setup. Completely Stock engine outside of the pertronix. The gas I've gotten since June I believe was all from the same station. Maybe I'll try another one.<P>HTH!<P>-Scott

[Guest]

Tonight I replaced the plugs with R43TS. The R44's that I pulled out all showed "hot" condition except 2. I believe the knocking I have/had was spark knock. Hopefully that got fixed tonight.<P>Before 10pm hit, I pulled the weights off the distrib, few min ago I took an emory board to each side. They cleaned up nicely and are now smooth on both sides. In the morning I plan on emory boarding the plate the weights sit on so everything have a smooth surface to work with. I can't do much with the springs, but they appear to work fine. Maybe while I had that '70 Skylark at the yard I should of pulled more then just the 4bbl setup. Hindsight will kill ya. <P>I'll post my results in the morning when finished.<P>Any other ideas?<P>-Scott<P>p.s. arching the rear bat cable on the alternator with a screwdriver shouldn't of hurt anything, right? I stupidly was trying to move and budge some stuff and the screwdriver hit the connector, sparks flew, I flintched. I immediatly removed the negative cable. Just would like to know if I blew another alternator before I start a trip tomorrow hopefully. TIA!!!

[old-tank]

Scott<BR>There is no way on the car to really test the advance weights unless it is completely shot.<BR>Your should be able to rotate the rotor a few degrees against spring pressure and it should snap back to the resting position completely and consistently, I had one that passed this test but still stayed advanced in use and caused horrific part throttle pinging. You can try to dissasemble the weights and wire brush (no grease or oil) and change the weights,...this did not work for me...everything was replaced by a distributor shop and then recurved. Best overall performance: set the timming advanced until the engine pings slightly on ful throttle acceleration then back off a few degrees or go the next higher octane gas; if you have an adjustable vacuum advance lighten up on the adjustment (less vacuum to move it) until you get part throttle pinging. Spark plugs will not last in an engine that is constantly pinging and are seldom the causeof pinging.<BR>Willie

[Guest]

It shouldn't have hurt your alternator. A person should always disconnect the ground on the battery before working in an engine bay. (I am guilty of not doing it most of the time)

[Guest]

Tonight's update & Q's..<P>I got'er runnin pretty good and drove 'er to a show. The knocking is almost gone, just happens lightly and rarely now. The pinging I'm beginning to think isn't pinging at all. Today I ordered a thick base gasket and a curve kit from napa and will pickup tomorrow. Also on my list -o- things to try for tomorrow is removal of the flywheel cover. It seems strange, but these problems seem to have started (if I remember correctly) when I replaced my starter. So tomorrow the cover comes off, new base gasket goes on, and hopefully I can ask someone here about the curve kit I'm getting. :-)<P>I emory boarded the weights and base plate and with the rotor on, it appears to move quite freely now. A new distrib isn't in my pocketbook at the moment unless someone wants to donate or barter a good unit. ;-)<P>Many Thanks!<P>-Scott<P>{73 electra fan: thanks for the reply }

[Guest]

Latest -n- Greatest Update FWIW:<P>I unplugged the vac advance and drove 'er round last night. At first I thought it fixed the problem, but allas, it didn't.<P>I *was* rather amazed at how the engine performed without the vac advance on the highway. Climbed to and exceeded 90 w/o haste. Not that that's a common thing, but can come in handy at times.<P>So anyone have any other ideas as to what it might could be? As above, I'm thinking maybe the flywheel cover, which I'll findout later today. If it is, I hope nothing is damaged. Anything else I should check?<P>I picked up a recurve kit, and in all honesty would like to ditch the vac advance as many people have. Is it possible? The kit came with 3 spring sets. Light, Medium, and Hard.<P>I would have posted sooner for more replies today, but my computer started acting like a 5yr old who doesn't get anything in a toy store. :/<P>Many Thanks!<P>-Scott<P>p.s. Steve, i'm working on it.

[Steve B]

Scott,<P>Did you make sure the mechanical advance bushing is still in place? Your curve kit may have come with one. You will get too much advance without it, and it may ping even when you set the initial advance right. It made my 401 run like, well not too good. The bushing is on the under side of the advance tower and it is hard to see with the distributor in place. They tend to disappear after a while. I just pushed the new one on, but I have often heard people recommend epoxying it into place. I would also make sure the vacuum drops to 0 on the port you are using for the vacuum advance when you move the throttle quickly open. <P>Thanks for struggling with that other matter.

[Don Caithness]

Scott,<BR>Steve is right on the money about the mechanical advance bushing. You can also have a machine shop make them up drilled off center and of differing wall thickness so they will act like a cam and you can further tailor the total mechanical advance. It's a matter of trial and error as to how much mechanical advance each car can accept.<BR>Good Luck

[Guest]

I honestly didn't see or notice the bushing, but I didn't know it was on the underside either. Will look tomorrow for it. With the vac advance unplugged, I got roughly 10deg advance from the weights & springs.<P>Whats strange, I tested the port I use for vacuum, and compared to the vac pump test on the advance. If they correlate correctly, the vac advance wouldn't kick in until after 2500rpm, maybe higher. That can't be right can it?<P>The pump test showed the advance starting to move at 30hg through to 60hg. The port test I didn't get past 25hg and that was a tad over 2000rpm. The port @ idle shows 0, as you move up rpm wise, so does the vacuum.<P>Whats strange is it seemed to respond better with the vac advance disconnected. Can't be right either can it?<P>I "did" fix my 'so-called' pinging problem. It was the flywheel cover! I removed it, cleaned it, bent back a piece and reinstalled with the lip over the oil pan. No more pinging type sounds, and the trans shifts a bit smoother. The knock is still there, tho not as bad, and only when first started. Which makes me thing it's probably related to my valvetrain noise.<P>Don, do I understand you correctly in presuming that you can't remove the vac and go straight mechanical? How can you tell how much each engine can take?<P>Many Thanks!!!<P>-Scott

[Don Caithness]

Scott,<BR>You can run mechanical advance only but you will find your gas mileage will drop. The mechanical advance rates should be in the shop manual. Total advance needs to be tailered to gasoline quality, engine condition , etc. Like I said, trial and error is usually the case.

[Guest]

Don,<P>Call me stupid if you will, (really!) but how would mileage drop if you were able to get the total advance the same as with a vac advance? Right now I have 91 octane in the tank to try to stop ping and knock which I've done. I usually run 89. I did notice running with just a mechanical ~24 total advance my mileage suffered.<P>I never mind trial-n-error (i live that way), but can ye aid me in the methods of tailoring?<P>Thank Ya!<P>-Scott

[Steve B]

Scott,<P>The vacuum advance opperates over and above the mechanical and initial advance when there is vacuum present. Under light load, conditions the engine can stand the extra advance and it will increase milage to have it advanced. There is a strong vacuum signal under these conditions, and the vacuum vacuum advance increases as the vacuum signal increases. Under wide open or high demand conditions, there is no vacuum or less vacuum. the vacuum advance reduces or is eliminated under these conditions. It is a good thing that it is reduced as the engine would not be able to tollerate this much advance and would perform poorly under high demand or wide open throttle conditions. After a certain RPM, say 2500, your engine really wants less advance as the rpms increase for max performance. Hence, the old Stinger systems retarded timing after a certain rpm by 2* per 1000 rpm. Hope this helps.

[Guest]

Steve B<BR>You are describing the ”modern” ignition advance system with the vacuum advance connected to manifold vacuum. This system is used, as you say, to give more advance under light load conditions to give better gas mileage. My 64 401 have the “old” ignition advance system with the vacuum advance connected to ported vacuum (carb venturi vacuum), that gives more vacuum advance under high load (high ported vacuum).<BR>Reading CyberBuicks description of his vacuum gauge readings his vacuum advance is also connected to ported vacuum and not manifold vacuum as Steve B suggests.<P>CyberBuick <BR>I assume your vacuum readings was taken with no load i.e. just revving the engine with the car stationary? If so your readings are OK, the ported vacuum will be higher under load and your vacuum advance will kick in sooner. This means that your total advance is the initial advance PLUS the vacuum advance PLUS the mechanical advance.<P>Vegard<BR>Norwegian BCA member