Check Engine & self-diagnosis LED blinks 1 time

I have an 89 Civic LX 1.5 with intermittent problems. The check engine light comes on and the self-diagnosis LED blinks once. This indicates the Oxygen Content according to the Chiltons Manual. If I am reading the chart correctly it indicates that I may have a bad fuel injector, map or o2 sensor. At times when this happens I have crappy performance and pinging like crazy, then later the car just runs great. Anyone seen this and if so, what is the fix?

Replace the O2 sensor. According to the honda service manual it suggests replacing the O2 sensor. I have had that code on all three of my engines and replacing the sensor has taken care of all of them.

Another symptom is that the temp gauge is very erratic when this happens. The temp climbs to nearly the upper limit and will then plummet to normal. This change to the upper limit is very quick ( in a matter of 10 to 20 seconds ). When the temp drops it is even quicker. It moves from about the 1:00 position to the 4:00 position in about a second or 2. Any ideas ???

For Code #1. Warm your engine until fan comes on, then off. Also make sure the fan is working, since you have a cooling problem(which my guess would be fan or thermostat problem) After the fan has shut off(if it works) turn off the engine & pull the hazard fuse from the under-hood fuse box for 15 seconds(reset ECU). Replace fuse & start engine, check for re-coding. If light does NOT come back on, dont worry about it. If the light does return, check the fuel pressure & reg, along with vacuum hose. I'm guessing O2 sensor is bad & needes to be replaced.

When was the last time your coolant was flushed or drained/filled? Should be done every 30K or 24 months. Changing the coolant will not fix a bad thermostat.

http://www.binghamtonlife.com/manual/2gsm/images/91-11-26.jpg
http://www.binghamtonlife.com/manual/2gsm/images/91-11-36.jpg
http://www.binghamtonlife.com/manual/2gsm/images/91-11-37.jpg
http://www.binghamtonlife.com/manual/2gsm/images/91-11-106.jpg

For Code #1. Warm your engine until fan comes on, then off. [/url]

ECU Code #1 is the O2 sensor. But that stuff might help him solve his cooling issue.

http://www.fourthgenhatch.com/photos/helms/helms-89civic-11-22-fuelinjection.jpg

See, this is the thing. I never have a cooling problem unless the Check Engine light comes on and the engine starts running like crap, then the cooling issue may ( like I said MAY come up )come up. Not always. Otherwise there is never a problem even in the heat of the 100 + days here in Phoenix. The temp doesn't climb UNLESS there is a check engine light ON and not immediately. it could be miles down the highway or it may not happen at all.

Where did those maunal pages come from? This is more detail than I have from the Chilton's Manual.

just change the O2 cheapest way to find out if thats the problem

otherwise check the resistance of your fuel injectors with a multimeter they are supposed to be something like 4-7ohms if one of those guys is dead that could lean out the fuel mixture and theres an overheating and pinging problem or your thermastat is sticking there cheap too

probably not an injector...the o2 sensor or thermastst are both cheaper than a tow home!!

good luck!!

Where did those maunal pages come from? This is more detail than I have from the Chilton's Manual.
Thats what you get for buying a Shitlons repair manual. Those pages come from a factory manual - I know of an online version for a 1991 CRX, covers mostly 89-91 CRX/civic http://www.binghamtonlife.com/manual/2gsm/default.htm The best investment for your car is a factory repair manual.

ForthGenHatch I said to warm the engine because its always a good idea before you reset the ECU. You should ALWAYS reset the light before throwing money at uneeded parts.

I had a code 1 once, reset the ECU & now 30,000 miles later the code has not come back. It would be kinda stupid to replace the O2 sensor since it didnt need it.

I had a code 1 once, reset the ECU & now 30,000 miles later the code has not come back. It would be kinda stupid to replace the O2 sensor since it didnt need it.


Nevermind. I saw "radiator fan" in and thought you were saying code 1 was radiator fan. I sort of realized what you meant later but I was too lazy to change it.

And yes my pages come from the Helms. They are a good $60 well spent for an entire in-depth book about how to take your entire car apart.

helminc.com

So does your scanned page there mean that if the diag lite comes on and just stays on that it's a bad ecu? I have one that the lite just comes on and stays on when you plug it in.