Farrar's car blog

[Ron]

The nut on an instrument of the viol family is that small light-colored piece or plastic/ivory at the very top of the fingerboard. It has indentations in it to help hold the strings in place. If your instrument is cheap or badly-maintained (and his was) it is possible to break the nut at one of those indentations as they are naturally that piece's weak spots.

Back on topic: found out that the small cigar I bought at the gas station is grape-flavored. Ew! I am glad I don't need to smoke it for very long to do my test.

Farrar

Woosh....(never mind)
Sure, guitars and banjos (not part of the viola family, but a "vulgar" instrument) have them as well...On mine the 5th string has a brass nut...and 24 stainless steel nuts around the head. Beat that! (All puns intended.)


Also back on topic: +1 Cherry cigars are much better.

[Farrar]

Cherry cigars are much better.

If I ever have to do the smoke test again, I will be sure to ask for one!

Farrar

Okay, I conducted the smoke test tonight!

I had to improvise a bit, because I expected to be able to pull the carburetor off without the adapter plate intact. Unfortunately, this proved not to be the case -- the adapter plate is held fast to the carburetor by the giant gasket atop it.

So there went the two vacuum ports I thought I had available to me. After removing the carburetor/plate, I was staring at a bare intake manifold with just the two plenums available.

My first thought was back to a repair I once saw a guy do on his vacuum cleaner: where the hose adapter had broken off, he had simply duct taped the hose on. I tried this method: I stuck a bit of vacuum tubing into one of the intake plenum holes, and taped around the hose and the manifold to make a good seal. Well, the seal wasn't quite so good, and I used my 99-cent cigar up trying to make the thing air-tight. No good.

So I removed the tape/hose assembly and thought: One source of vacuum leaks on K-Jet cars is at the injector ports! On Sparky's engine, I have those plugged with silicone taper plugs but they're easy enough to remove. Fortunately for me I have bits of hose in various sizes, and one of them happened to be just the right girth to fit into the injector ports with a little force and make a good seal. So this is the method I decided to go with. I taped off the plenums and stuck the vacuum hose in an injector port on each side. I lit a small cigar and blew smoke into the hose -- or I tried to. Although I could see the tape over the plenum move under the pressure, I couldn't actually force any smoke to come out anywhere, and as soon as I took my mouth off the hose, a puff of smoke came out that end. This happened on both sides.

I have now verified that my intake manifold is leak-free.

Farrar

[Bitsyncmaster]

You would need to do that smoke test at night with a flash light to get really sensitive results.

[Farrar]

This was done at night.



Farrar

[AdmiralSenn]

Question for you. When you did the smoke test, did you consider the valve positions of each cylinder? If your injector plugs are the source of the leak (unlikely, I know) they likely wouldn't show any smoke unless the relevant valve was open.

I'm leaning towards a spark problem, myself. Have you tried advancing the base timing to see if it helps any? When I was tuning my car at low RPMs I would sometimes have to bump the timing all the way up to get it to idle smoothly. Maybe it got bumped or something?

[Farrar]

I have assumed that my valves leak, since I've been finding dirty, smoky, congealed oil in the injector ports for a long time now. But you're right -- I hadn't taken that into account and I should probably have checked all three on each side instead of just one per bank. Well, fortunately I have plenty of small cigars handy (although I could swear I still stink from yesterday's test!) and will have a little time on my hands tomorrow evening. I suppose another way to do it would be to pull a vacuum from each of those ports.

At this point I am also thinking it's a spark problem. According to MSD, I can send full voltage into their ignition coil, but I have been using the stock resistor (bridged) anyway. I might bypass the resistor and see if it does anything to improve the situation. The timing has not been altered since 2008 -- the crud buildup on the adjustment screw by the distributor would seem to indicate that. :-\ Also I will reduce the gap in the spark plugs and see what that does.

Farrar

It just occurred to me that I still have no interior lights in my car. I was hoping to drive it this weekend, but that involves a Friday night excursion. Hmm. I guess I had better fix that problem before I get back to the rough idle problem.

Farrar

Something is definitely screwy with my courtesy lights: I unplugged the passenger side door switch and the lights stayed on. Plugged it back in and depressed the switch, and saw the lights dim but not shut off (even after the appropriate amount of delay). Unplugged the driver's side door switch and felt the leads to be warm to the touch! I pulled the fuse so now I have no lights at all, but at least the circuit isn't warm.

Note: I have no dome light or glove box light right now as both fixtures are missing.

Back when I had a dome light, it would only come on when the doors were open; I was unable to make it come on by tilting it like you're supposed to be able to.

Looks like I am going to have to simply start disassembling the courtesy light circuit. Maybe I will install an override switch while I am at it -- it would be nice to hit one of the rocker switches and have all of the interior lights come on like in a modern car. No doubt it will take me weeks to accomplish this... and I might as well start by removing the knee pads. (Easy enough to do, since the passenger side knee pad is falling off despite my many attempts to get it fixed.)

Farrar

[Farrar]

I have no dome light

...until next week. I figured out that the interior light fixture from a 1989 Porsche 911 is a cross-reference, so I ordered three online (free shipping on orders over $65 from this seller -- I ordered two more for some friends )

Troubleshooting in earnest begins, I suppose, this weekend... if I have the time. I do have German and Biology mid-term exams next week, plus the fundraiser at the radio station which means 9am-7pm workdays, so I may or may not have any time at all to work on the car until after 21 October.

Farrar

[AdmiralSenn]

Let us know if the new unit is an improvement in any way on the old one. One of mine is flaky and the contacts are so flimsy that it's no wonder they don't work any more after 30 years.

[Farrar]

Let us know if the new unit is an improvement in any way on the old one.

Will do. They ship today.

FWIW, the new dome light fixture looks exactly like the ones DMC Houston sells. I will post comparison pictures if you like.

Farrar

[stevedmc]

Let us know if the new unit is an improvement in any way on the old one. One of mine is flaky and the contacts are so flimsy that it's no wonder they don't work any more after 30 years.

I have one for my front dome light and YES it is a huge improvement. It isn't flakey, it is built solid, and it works every time. I love it.

Honestly I was thinking about ordering the cross reference a while back but the cheapest I could find was $31 as well. I think DMCMW sells it for $35. I was just going to wait and order another from DMCMW with my order but I've made several orders since then and keep forgetting about it.

Farrar is hooking me up with some free shipping though. Yippie.