91 Civic DX Staling Issues

A.Rose91

New Member
I was driving to work this morning and My honda stalled at a light. It's done this before but it was the distributor which we fixed. I replaced basically the whole fuel system last week (Pump, Filter, Fuel Line, and Tank) I know my Idle Control Valve is going but when I got it back up and running, it almost stalled again but I caught it and tapped the gas and I noticed that the battery light was on while it was sputtering. Could it be the Alternator??
 

Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
Have the battery and alternator tested.
 


machonda91

New Member
Since the battery light was on, that will throw off a code in the ECU. You peel back the front passenger carpet, and turn the ignition on (no crank). Count the number of blinks of the light. Do this several times to confirm. It may throw off more than one code with blank interval in-between. number 1 code is elusive because it will do that just for turning the key on, so it might apply, it might not. There are references online for how to read the codes on 88-91 civics, or in a Haynes manual of the period. Could be alternator, how many miles on it? My guess is you have a #14 code for the idle air control valve, since you say you have some reason to believe it's 'going'. I had to clean my IACV (flip upside down, soak interior 30+ mins in throttle body cleaner - twice, rinse a little, probe with mini brush/pipe cleaner, screen should be clean and bright. If you get particles out of it, THAT is progress!). After reinstall you will get idle surge up and down once it's warmed up because of air bubbles in the cooling system. You have to burp when cold by squeezing upper and lower hose with rad cap off - several sessions of this - took me weeks. Also may be relevant: I also cleaned my fuel injectors the previous year. Particles can get in there too. And to be complete, first check the throttle body and clean that. I had goo on the edge of the plate that flaps up and down. That made it sticky here or there. Ask me questions I've been all through this the last 2 years.
 
Last edited:

Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
Since the battery light was on, that will throw off a code in the ECU.
So the ECU registers a code for the battery light, what code and why doesn't the CEL come on?

I've never had any code come up when/if I've had a bad battery or alternator.
 


machonda91

New Member
I definitely had the battery light come on when the alternator went on my '86. The orange battery light functions as a sort of CEL. It was the same with the '91. Once the battery light was on when the car was running, it threw code 14 - IACV. You're right, there is no specific batt/alternator code, but the light is on and a code generated to something that's underperforming from the low alternator operation. I recall testing the alternator because the battery was not charging well, headlights causing changes in idle, battery measured at 11.8 volts even after running, and about 12.4 when running (should be about 14.2 or so). So I replaced the alternator, and soon after the solenoid. Have had no problems since.
 

Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
I definitely had the battery light come on when the alternator went on my '86. The orange battery light functions as a sort of CEL. It was the same with the '91. Once the battery light was on when the car was running, it threw code 14 - IACV.
But the actual CEL doesn't come on.
I've had a few battery's and alternators go bad and the battery light has come one, but never had the CEL on the dash come on because of it.
 

machonda91

New Member
In an '86 Civic there is no actual CEL. It's just a yellow light labeled "battery". But when it's on, you've got electrical problems. The battery was weak for many months, thought it was going. But once the battery light was on, other things began happening. Turning on the headlights was a major draw on a running car. High beams worse. And I blew a taillight bulb. I never blew one before in 159k miles. Battery was weaker and weaker, starting sometimes just a click no power. Finally tested the alternator with a multimeter. THAT was difficult for the novice, but there were youtube videos.

In old civics there can also be grounding issues, esp main battery ground under the battery on the fender. I think they get to an age where you have to rework parts of the electrical system. From the original post, it sounds similar to my experience with IACV, throwing off code #14.
 

Mr.Baker

Mr. Search
Registered VIP
5+ Year Member
In an '86 Civic there is no actual CEL. It's just a yellow light labeled "battery". But when it's on, you've got electrical problems.
The 4th gens don't work light that, they have a battery light and CEL, battery light illuminated means you have a fault in your electrical, typically battery is bad, then leading down the road to check alt., grounds etc...
This shouldn't in any normal circumstance set the CEL on for the 4th gen cars.


OP, test your alternator.
Also, how do you know your IACV is "going bad"?
 


Top