I have a 1989 accord lxi with a strange problem. It will start up fine cold but idles a high, 1500-2000 range. While the engine is under the normal running temp the idle stays this high and the car will run and drive perfectly normally. Once the car gets up to running temp the car will stall whenever I give the car more gas. It wont kill the engine unless the car is in drive and at a complete stop, the rpms will drop by 500-1000 and then come back up to normal in any other case. Recently there has been an addition to the pattern. When the car reaches operating temp now after stalling like usual a few times the check engine light pops on and the car will run normally as if there is no problem. When I tested this in park the rpms rev to 2000-2500 at operating temp and then when check engine light comes on rpms will drop to normal low idle 700ish. I have alrdy cleaned the IACV,and EGR, replaced a couple vacuum lines that looked cracked, and replaced the cat. converter. Any ideas would be helpful, to get the ball rolling i read in another online forum that the engine coolant temp(ECT) sensor can cause problems like this.
On this car, actually the coolant temp sensor won’t cause this problem because the high idle is controlled by a separate mechanical thermal valve, which is a common cause of idle problems on these. But since yours works fine when the check engine light comes on, that probably isn’t your problem. Have you checked to see what the stored code is yet? Here’s a website with directions:
http://www.troublecodes.net/honda/
Check the code and post back.
The Chilton’s Repair Manual, part #8255, has the troubleshooting charts such as Fig. 73b, here: http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?chapterTitle=Troubleshooting+Charts&partName=Driveability+%26+Emissions+Controls&pageId=0900c1528005f5bb&partId=0900c1528005f53e For your rpm problem, it indicates that the Electronic Air Control Valve may be the cause of the problem. The repair manual, later figures, tells you how to check that valve.
ok, found a LED in a control box under the drivers seat. When the ignition is on it flashes 12 times. If im getting this right that means EGR system. Any thoughts on which part of the egr could be causing this?
There’s probably a vacuum leak somewhere in the system. There’s vacuum diaphragms in the control solenoid and in the valve itself so either could be leaking. To properly diagnose it from this point, you’ll probably need a manual that explains how the whole system works and has a diagram.
The trouble code you saw flashed was probably Code 13. Codes 11, and 12 aren’t assigned to the 1989 Accord. Code 13 indicates: “A problem in the Atmospheric Pressure (PA) Sensor circuit.” The Troubleshooting Chart for Code 13 is on page 4-93 in the Chilton’s Repair Manual #8255.
The troubleshooting charts are shown at www.autozone.com at Fig. 72a & 72b after you register at the site. Since there are 320 charts, it will take several minuets (maybe, 20 minuets) for the download to complete to your pc. The information is there. It’s up to you to avail yourself of it. http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?chapterTitle=Troubleshooting+Charts&partName=Driveability+%26+Emissions+Controls&pageId=0900c1528005f5bb&partId=0900c1528005f53e