1987 Honda Accord

I brought my car into the shop at work yesterday and plugged that hole in the left rear tire. I also snugged up the alternator belt to stop that intermittent belt squeal. I hate using those quick tire plugs that you put in from the outside, because I just don’t think they last very long. But I’m prepared to replace the tires (they are eight years old) so the plug is really just temporary.

I modified my carburetor again. I bent a tab on the choke which prevents it from be able to close completely. Doing this has made it run much, much, much better when cold because the mixture isn’t so rich. It hasn’t made the car any more difficult to start, which is a good thing.

I also tested my battery, and it came up as good on the tester (a VAT45) but it showed only a 58% state of charge. Given my driving habits, I believe that it should be fully charged, so the reduced state of charge is really more an indication of the battery’s age. I intend to keep the battery until it gives me trouble starting the car.

Lastly, now that I’ve learned how my car liked to be shifted, I’ve virtually eliminated the grinding I was getting in first and reverse. The trick is to shift quickly into first, before the mainshaft has a chance to spin down. But to pause for several seconds when shifting into reverse to let the mainshaft completely stop spinning. And the 10W-30 that I put in the last time has had an effect on the shift feel, but I think it’s an improvement. The 10w-40 that was in there made for a slightly mushier feel, compared to the slightly notchy feeling from the 10w-30.

My car hit 170,000 miles this week. w00t!
My CD player has an affinity for scratching CDs during loading/unloading.
The vacuum choke must be busted, because the car runs super-rich until the electric choke kicks in and opens the choke. Maybe I can find a way to alter that behavior this weekend before the weather gets really cold and things get worse. I just wish my car had a cable choke. That would be really cool, and it would solve this problem.

I got a cheap CD player off of eBay. It works. It took some fixing, but it works, and I have music, and more importantly I can listen to CDs!

I changed my oil and transmission fluid over the weekend. The car has 169,500 miles on it. My car is burning some oil these days, and I think it may be burning a small amount of coolant as well.
I changed to 10W-30 oil in the transmission. I can feel that the shifts are a little stiffer and notchier with this oil, but I’m going to keep it for a while and see how it goes.

My radio broke yesterday. I took it out. Stupid radio. No tunes for the ride.

This next part is kind of technical, and I have little interest in simplifying it.
I think I figured out how to get first gear to stop grinding. The problem was that the synchronizer sleeve wasn’t fully engaging both sets of dog teeth. I originally thought I’d ease the load on the synchros by putting the clutch in and waiting several seconds until the mainshaft spun down. But in fact, I was dead wrong. The key has been to shift into first quickly after putting the clutch in so that the mainshaft is still spinning. I’ve done this for about a week and virtually eliminated the grinding. Reverse is still a problem.
I suppose I should have figured this out sooner. Whenever you try and shift a transmission with the car stopped and the engine off, you often can’t get every gear because the dog teeth aren’t lined up, so you only get partial engagement of the gear.

On Monday my car started making a squealing sound, but it pulsated. I thought it was related to the power steering belt, but I took that off, and the sound still occured, so it must have been the alternator/water pump belt. The one disturbing thing is that the crankshaft pulley doesn’t run true. It seems to wobble both laterally, and vertically. I don’t know if this is the pulley, or if excessive endplay in the crankshaft is causing the whole crank to move. I suppose I should get a dial indicator and measure the runout.

The sound was almost gone today, but I replaced the belts anyhow, since the serpentine belt felt a little brittle. It’s only about two years old though. I had to buy a set of ratcheting box wrenches to do the job, and I have to say, they are just about the coolest tools I now own. They are in contention with my impact wrench for top spot. Well, that’s all for now.

I changed both bushings on the “torque rod” today. Those weren’t very cheap either. I was hoping it might lessen the clutch chatter. It didn’t. Damn.
The bushing was worn, but replacing it didn’t seem to have much effect at all. I still believe one of the engine mounts may be the source of the problem, but I guess I’ll have to approach the diagnosis more thoroughly now. I was really hoping the torque rod bushing would do the trick.

So I replaced the header pipe, my car is now beautifully quiet.

I tried the water trick, but I don’t think it really did anything. Most of the water seems to have ended up in my oil, which I also changed.
In the process I discovered that the vacuum hose for the PCV valve was torn, so I replaced that. I think that helped smooth out the idle a little bit.

I replaced the O2 sensor, that was easier than anticipated. I think that’s about it. I just love my quiet car now.

Okay, so last Thursday I did some engine diagnostic tests on my car.
First I did a dry and wet compression test. The results.
[Cylinder, first reading, final reading, dry/wet]

• #1.) 110-190 dry
  120-210 wet
• #2.) 80-150 dry
  120-180 wet
• #3.) 90-130 dry
  90-175 wet (second time was 120-180)
• #4.) 110-180 dry
  130-220 wet

Next I performed a cylinder leakage test. The results:

• #1.) 10-15% leakage into crankcase.
• #2.) 15-20% leakage into crankcase
• #3.) 20-25% leakage into crankcase and into cylinder #4
• #4.) 15-20% leakage into crankcase

Interpreting these results is the hard part. The relatively low leakage numbers indicate the rings and valves are doing a good job sealing. There was still oil in the cylinders from the wet compression test which may have artificially decrease the leakage. The most interesting thing was the leakage from cylinder #3 into #4. I repeated the test several times to verify this. There were no signs of leakage going the other way.
The compression numbers tell a more interesting story. Since the leakage test makes me think the rings aren’t too badly worn, the low first reading in the compression test leads me to believe there is a volumetric efficiency problem. Possibly a worn camshaft, but I think it is more likely that there is carbon buildup on the back of the valves restricting airflow. Cylinders #1 and #4 had high final readings which may be caused by carbon buildup on the pistons and the combustion chamber. I could visually see the buildup on the pistons through the spark plug hole. Clearly there is an issue with cylinder #3. And #2 shows some deviation from the others as well. The uniformly low readings for #2 and #3 could indicate a head gasket leak, except that the leakage test shows the leak is between #3 and #4.

Overall the results aren’t too surprising for an 18 year old car with 166,000 miles on it. All things considered, the car runs very well.
This weekend I have a plethora of work planned for the car. I’m going to start by flirting with disaster and attempting the old water through a vacuum line to “steam clean” the combustion chamber. This should be either very exciting, or prove to be fatal. I’ll let you know.
Also planned: oil change, O2 sensor, exhaust pipe (header pipe), possibly the carburetor base gasket, and check the ignition timing.

I turned the fast idle speed down. Because it wasn’t kicking down from the fast idle cam soon enough, I decided I’d just lower the fast idle speed to mask the greater problem.
I also observed that the exhaust pipe is now broken right before the flange for the catalytic converter. That’s the section that has my hack work exhaust patch. I’ll replace it before the year is out, hopefully before the summer is over.
I also want to replace the oxygen sensor. I was never quite clear what the sensor did on a vehicle with a carburetor, but from reading my text book I believe it controls the Primary Slow Mixture Cut-off Solenoid Valve, which controls the A/F ratio.