Hello,

Sort of new here, been a member but haven't been on at all.

Anyways, I have an '89 EF Hatchback I bought back in 2011. It had ~150k and according to the previous owner he rebuilt the engine. Runs smoothly for it's age, other than the fact it idles erratically, sometimes. Other times it's fine. Typically when my gas is older is when it will idle funny. The car now has 174k on it. Only things I've done in the time I've owned it is replace timing belt (broke on me about a little over a year ago) as well as put a cat conv. on it right after I got it, he had a glass pack type thing instead and my county does emissions and wouldn't pass without it.

So 2-3 months ago I had the check engine light come on when I was cruising down the highway, I had stopped to put some gas in, it went off. Came on again on my way home, I got home, shut it off, didn't drive it til the next day. Since then it had not come on again until a week ago, did the same thing, once turned off, it "went away". I bought a oxygen sensor out just because I thought it may possibly be something pertaining to improper fuel mixture.

For what it's worth, whenever the check engine light would come on, it would no long go into over drive.

Other than that, there doesn't seem to be any other issues, so I haven't really probed into it too deeply. Now I am starting to worry about my baby and want to nurse her back to health.

Next step will probably be replacing fuel pump/filter (it's all one unit right?). Unless y'all think I should start else where.

Any advice will be greatly appreciated. Thanks!

 

Check the code. The 1988-1991 models have a blinking LED on the ECU itself, which is under the carpet on the firewall where the passenger's feet would be.

The led is always active, you do not need to put in a test jumper or scanner. Turn the key on but don't start and count the number of blinks. Note that there is always a single short blink when the key is first turned on, ignore that one.

Fuel filter is on the firewall connected to the hose that goes to the throttle body; easily replaced but it isn't likely to be the cause of your problem.

 

Alright, I did that just now. I had 1 flash like you said upon turning the key on, I'm not sure if it did another single flash right after that, and then continued to 2 sets of series. I made out 7 flashes, then 16 flashes.

89 Civic EF blinking LED errors - YouTube

I just made that video while I did all this. Just in case I'm counting it wrong.

I think I remember doing this once before, I had forgot these civics had this convenient little feature. I don't remember what code I had before.

It doesn't matter though that the engine light is not continuously lit?

Thanks for the speedy response, by the way.

EDIT: Ok, watching it the video over, it clearly looks like, 1, 7, 16. Sooo Oxygen Content, Throttle Angle (TPS), & Fuel Injector seem like those are my problems.

Any advice on a good place to start?

 

Did you see one flash more than once? It should repeat in a sequence if it's a real code.

TPS can be tested with a voltmeter. Turn key on but don't start, measure from sensor's center wire to ground as you move the throttle from closed to wide open the voltage should vary smoothly.

 

Yes. When I initially turned the key on, there was a single quick flash, then another single, slightly longer flash, then it proceeded to 7, & 16. It then restarted, 1, 7, 16. Each time it ran through the cycle there was always 1 single flash at the beginning of each sequence. So I suppose that means my oxygen sensor is acting up.