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View Full Version : Help car has to smog before oct or its junk



cokewhite&graphite
09-13-2004, 11:40 AM
87 lxi, severly beten 150k on it, code 12, during slow acceleration (uphill) or cruising, checked the egr valve, works, checked the lift sensor and compared it to another egr valve I had, matched, checked the harness to the sensor, a 5 volt, a ground, and a ground with resistance, checked the solinoid, it clicks, checked the wiring harness, 12v at the dark wire, ground with resistance at the red one, i re-routed the vacuum lines to spec, and replaced the cvc (green and white thing) it has vacuum at the side port when the center is plugged in, also, the air chaimber in my e-box has an extra port than the one listed in the e-box routing pic I found on this website (from the shop manuel) and i dont know what hooks up to this 3 rd port, (right now its #17 into the intake before TB, i appricate the help thanks -Shawn M.

88LXi/87CRXSi
09-17-2004, 10:58 AM
It sure seems as though you've checked and eliminated pretty much every thing. I do remember reading a while back on another site that getting a code 12 under the conditions you have, can be caused by that air chamber you mentioned. That site said that there are orifices in that thing that get restricted or clogged partially. This causes the valve to open/close slower than the ecu expects it to, causing the error code. Don't know if you can clean it, :dunno: they said get a new one from the dealer. Or get the whole emmisions box from a bone yard donor. As far as the third port you mentioned, don't have a clue, my car and helms manual are for a '88, and I think the '87 is different. Hope this helps keep your car on the road and isn't a waste of time/money!

88LXi/87CRXSi
09-17-2004, 12:27 PM
Did some browsing on my hard drive, found pretty much the same info from another web site.
http://www.parttrackers.com/library/1/93/95/

Bill Sauer, founder of Autoline Telediagnosis (a technical hotline company with thousands of subscribers), was generous enough to offer us the help of his talented personnel on this diagnostic series. So, we spent hours talking with Marlowe Peterson, who was a Honda dealership tech for 12 years. Now, as Autoline's Honda specialist, he fields an incredible number of tough troubleshooting calls on a daily basis.

One of the most common problems especially on '86-'89 Accords and Preludes is an EGR Code 12," he told us. "The system has manifold vacuum going into the emissions box where a constant vacuum valve maintains 8-12 in. Hg. This vacuum supply is teed off with one leg going to the EGR valve and the other (hose #17) to the solenoid that vents vacuum. Instead of using a regular tee, there's a white plastic air chamber with a couple of orifices in it to dampen the vacuum signal to the EGR valve so that it opens within one second. What happens is that pieces of the hose plug the orifices. The EGR may work, but it doesn't come on fast enough to make the ECU happy. It's impatient, and when it doesn't get a signal from the EGR lift sensor, it sets the code.

To save time, find the single two-wire connector at the emissions box, and check that the black/yellow tracer wire is hot with the key on. At idle, ground the red wire and the engine should stumble within one second. If nothing happens, see if there's voltage at the red wire. If so, the EGR control solenoid coil is probably open. If you pinch off hose #17 and the engine stumbles, the solenoid is bad.

To test the constant vacuum valve, put your vacuum pump on the hose from the air chamber. You should see 8-12 in. Hg. at idle. Then, bleed off the vacuum and it should come right back," Peterson said.

shepherd79
09-17-2004, 12:49 PM
take the EGR valve out and clean it with carb cleaner. make sure the valve opens freely. put it back, reset ECU fuse #10 and 11 under the hood fuse box. pull them out for 10 seconds or diconnect ground wire for 10 seconds.
if you still get code 12, find EGR valve from junk yard that is good.