This is the follow-up to the last installment, where I went off the vintage Honda bike track into vintage Honda cars, when I purchased a cherry 1987 Honda Civic Wagon, recently.
After the car had just squeaked-by in the last smog test, prior to me picking it up from the sellers, I determined that the newly-acquired fast idling speed (1200 rpms vs. 800rpm spec.) was due to the “test only” shop fiddling with the base ignition timing, advancing it physically by repositioning the distributor. A “test only” shop is not supposed to do any kind of adjustments or mechanical repairs on the vehicle being tested, just “test it,” period.
My investigation into what had been done or needed to be done turned up defective EGR and distributor spark advancer diaphragms, which caused high NOX and HC readings, plus caused idling issues because the distributor advance diaphragm fitting was connected to manifold vacuum. This resulted in a basic “air leak” at the intake manifold, which only ceased when the line was plugged off on an adjacent 6mm engine stud that had a few threads sticking out past the nut. With the diaphragm having failed, the 20degrees before TDC ignition timing fell back to zero degrees TDC at idle.
During the test, when the EGR valve was supposed to be activated, the failed diaphragm barely allowed any movement on the valve pintle, which opens the passageway between the exhaust port and the intake manifold port. This allows the intermixing of the gases, which dilutes the incoming charge, effectively lowering the combustion chamber temperatures that cause high NOX output.
I contacted the sellers who refunded $100 to me to help procure some necessary engine parts to remedy the conditions noted. Honda no longer sells any of these parts from their warehouses, so I went to eBay auctions and found a good used EGR valve for sale at $29, plus freight from LA. The distributor parts are also NLA, but were made available from several aftermarket companies, including Standard Motor Parts, Wells-Airtex and Echlin, which is a NAPA parts brand.
I was trying to do all of this parts searching right before Christmas, so a number of sources were closed for the holidays. Searching for the a/m equivalent of the OEM parts by part number allowed me to find a few on-line parts resellers, which had them listed as “available” for sale. Once ordered, however, the replies came back as NLA and refunds issued. One of the on-line orders didn’t reply right away, due to the holidays and I assumed that they would also get back to me with the same bad news.
In the meantime, I called local auto parts stores, most of which said “no listings” or “not available”, except for Napa and the local Carquest store. I had dug up catalog listings for the aftermarket brands and fed one of the four variations of part numbers to the parts guy, who checked national computers and determined that one of them WAS AVAILABLE at a warehouse in Iowa, but it couldn’t be shipped until Jan.1. Both of these parts were from the Wells-Airtex brands and in the interim I sent messages to the Wells company contacts I found on-line. None of these parts are currently listed on the Wells website, so I held out little hope of these parts actually existing somewhere. Between Christmas and New Year’s Day, I did receive a reply from a Wells employee stating that these parts were not to be found in their inventories, nor were they expected to become available again in the future.
Another dead-end or so it seemed. .. Two days after that message, I received an e-mail confirmation that my on-line order was being shipped to me from Wells’ warehouse in Iowa! Then, on the day after New Year’s Day, I received a call from Carquest stating that the part was being shipped from Iowa, as well. Sure enough, by the end of the week, I was in possession of two identical spark advancer units, both shipped from the Wells warehouse! These parts are not even made in the US, as the boxes were marked “Made in Japan,” probably by the same people who made them for Honda, in the first place. Well, the good news is that after removing the distributor to install the advancer unit and cleaning it up inside, along with an o-ring replacement on the distributor body, the OEM spark function is returned to factory specifications. I had to reset the ignition timing so that idling spark was coming back in at 20 degrees BTDC and some subsequent idle speed/mixture adjustments have settled the car down to normal, once again.
While the distributor spark function has now been restored, which would normally perk up any engine with insufficient spark timing, the overall effect was subdued because of the now functioning EGR valve, which does dampen horsepower by the nature of its design. When EGR valves fail or the passages become blocked with carbon, combustion temperatures rise back up which makes more horsepower, but generally also causes engine pinging/knocking due to too much spark timing that was designed to work with the EGR dilution function. Because of Honda’s CVCC stratified combustion chamber design, the engines seem to be less prone to spark knock, which can cause overheating of the valves and piston crown. Honda’s full spark advance curve is fairly conservative in the total combination of vacuum advance and mechanical spark advance, so no harm-no foul, in this case.
In the end, I now have a “spare” $65 distributor vacuum advance chamber for the car, which I may try to sell off separately. If it doesn’t sell, I guess it will become part of the “parts dowry” that goes with the car, which will certainly ensure proper distributor function for the next 25 years of this cars life. Knowing how many of these cars are still out there, most of which probably have failed vacuum chambers, makes you wonder how many will be taken off the road due to smog test failures, all because of a lack of parts.
In a final high note, the little wagon (stripped DX model) had been built without a RH side mirror, which is a little disconcerting when driving in traffic. The “greenhouse” views through the many windows allow for great visibility, but one becomes used to a RH mirror on today’s cars. I had waited for a holiday reply from an eBay seller, after searching diligently for a good used part, which is specific to the Civic Wagons, alone. When the seller got back to me after the holidays, he couldn’t find it anymore and sent apologies. Another sweep of auction listings turned one up for an opening bid of $.98 with a couple days to go. I anticipated that someone would swoop in at the end of the auction, so I placed a bid, then a backup bid on the morning of the auction end. As it turned out, the seller was a private party who lived about 8 miles away in El Cajon, CA! At the end of the auction NO ONE had placed a bid, except me! So, I finally had my RH mirror for the wagon and was able to just drive over to the seller’s home that afternoon and pick it up. I felt so bad about the $.98 winning bid that I gave him $5 for it, anyway. It would have cost me about $40 from the auction junk yard dealers, judging from the last couple of listings, so I was way ahead of the game. The mirror adjustment handle was missing the end cap, which the seller didn’t have, so I checked with eBay again and found a seller with a half dozen handles with caps and screws for $5 each, including shipping. That was really the last piece of this Honda Civic Wagon puzzle, at least for now. Sometimes, you get lucky and get a great deal and sometimes you wind up with more parts than you really needed. In this case, TWO copies of a “non-existent” part; one for now and one for the future. I guess it was just a case of OAOS – Over-active ordering syndrome.
Bill “MrHonda” Silver
PS (Back to vintage bikes, next time, I promise, but the lessons learned DO apply here)