Howdy,
Okay, I have a 1991 civic LX 1.5L that is showing trouble code 16 on the ECU. I tested the Fuel Injector resistance and got something near a 2 ohm load for the main injector and 8.5 ohm for the auxiliary. I replaced both with rebuilts from checker which tested the same resistance (not smart I know, but bear with me). I replaced them because I heard that if the load wasn't between 1.5 and 2.5 ohms they are bad. Is this true? Anyway....

I also did the following in the last 50 miles:
- New wires and plugs
- New Fuel Filter
- New Air Filter
- New PCV (yes, it is installed right and tight)
- New Thermostat (I have warmth finally!)

I've done the following in the last 3 - 5k miles:
- New Main Relay
- New Distributor with new igniter and coil

The car will not go above about 3,200 RPMS (is this a safety feature? I have had other trouble codes and it seems that is always the point where it sort of cavatates) and gets worse gas mileage (roughly 27 average instead of 32). Any ideas? What can I test and how? Fuel pressure regulator? I hate just throwing parts at a car.

Thanks for your time!
Jeff

 

The facts that (1) code 16 isn't a real code and (2) your engine is acting like it is in Back-Up mode suggest that your ECU is malfunctioning.

 

There are quite a few forums out there that disagree with you: http://www.troublecodes.net/honda/hondadtc.shtml

I've read a lot about how ECUs go bad on these, but I've also read that the 3200 RPM issue is a response to a code and a protection feature. Most of my civic specific knowledge is stolen from other forums though, so please let me know if I'm full of hooey.

Thanks Ron!

Jeff

 

I can't say that you are wrong. Please let me explain myself.

The 88 Civic manual lists code 16, which indicates a problem with the fuel injectors (picture 1).

The 90 Civic manual supplement, on the other hand, does not list code 16 (picture 2), hence the statement in my first post.

My assumption, which may be incorrect, is that 91 Civic codes are the same as 90 Civic codes. I also don't have access to the 91 Civic manual to verify my assumption. If you have the 91 Civic manual, and it says that there is a code 16 for your Civic, then I stand corrected and apologize for the error of my assumption.

88 Civic:


90 Civic:

 

Yeah, that is super weird - but I will say that it blinks 16 individual short light bursts and then rests, and then repeats. It is more like the partern on your top scan. Thanks for that though. Any idea what would give the fuel injector trouble code? Is there a way to test the ECU?

 

Okay, the 90 Civic manual I have is for the B16A1 1.6 liter DOHC V-TEC Engine, whereas the 88 Civic manual is for 1.6 liter D16A6 to D16A9 engines. What specific engine do you have?

Given that your 91 ECU is behaving like the 88 ECU, here's how to troubleshoot code 16:

 

hey ron,
I have a 1.5L. I will double check the clicking sound on each injector, but they are both new rebuilds.

FYI it is a DPFI, so I only have an aux and main injector. Are you sure that both injectors should register 1.5 - 2.5 ohms? I get that on the new main injector, but not on the new aux injector. It's more like 8 ohms. This could make engineering sense, so I don't really want to just assume. What do you think?

 

My guess now is that the fuel injectors are fine. I Googled Civic code 16, and it seems that there can be a variety of causes for it, which you probably already knew. The best approach may be to troubleshoot the symptom, which I think can be characterized as loss of power. Some possibilities may be:

1) Faulty fuel pump
2) Bad pressure regulator
3) Engine timing out of spec
4) Clogged catalytic converter

 

do you know of any way to test the Pressure regulator?

I don'tt think it's th fuel pump or the converter - I can check out the timing (no gun though, so we'll see)

I'll start with the regulator

 

Here's some information for the regulator and timing: