psyguy23

resolved

I am having difficulty isolating a CEL 16; hoping more knowledgeable persons can help me solve it.

Setup:
B18C1
750cc Injectors
S300
OBD2 Rywire Harness
OBD1 P28 ECU w/Conversion Harness
UEGO Wideband
Bosh 5V O2

Series of unfortunate events:
Car starts.
Runs, but rough, and throws CEL 16.
Gauge cluster lights up, but tachometer and speedometer not working.
If I increase throttle even slightly causes car to putter and die; feels as if it's being bogged down with fuel.

Diagnoses thus far:
All injector clips are clipped in.

ELD D10 voltage readout on S300 matches within a few tenths of a volt to the corresponding A/F ratio on the AEM UEGO

Check injector clip order ... injector 1 is locate at the fuel pressure regulator, then 2, 3, 4 closest to the distributor.

Double checked soldering work - didn't need to solder anything for injectors so automatically rule that out.

Pulled main relay; tested continuity - test good + car starts. Figured this was unnecessary to test but prior "code 16 searches" showed a lot of people suggesting this.

Another long shot but - fuse under hood 15A looks good, not burnt.

Wondering about injector pulse in s300, haven't touch it, say that come up a few times in the searchers.

Checked all connections again.


Theories:
Something electrical is wrong with the Rywire harness because I am not getting any RPM or coolant temperature readings on the cluster. I am suspicious that there is an electrical short somewhere that is causing the injectors to not report back to the ECU and these two problems are related by theorized short.

I have a three connections that are not being utilized: narrow O2 connector, knock sensor connector, oil pressure sensor connector. I am wondering if the unconnected narrow O2 connector needs to be grounded/looped.


Next steps:
Hope more knowledgeable persons out there have suggestions as to what else to look for, I am feeling a little lost as to what to look for.

Call Rywire, pick their brains see if they have any ideas.

Thanks in advance

full Circling

a main ground not being hooked up within the harness might do that...

you're throwing a code 16, which is an injector, amirite? (are all of your injectors working? can you feel them pulse when you put your fingers on 'em?)
then you've got the tach AND the speedo not working...
the tach signal comes from the distributor (then to the ecu IIRC), and the speedo signal comes from the VSS on the transmission.

three seperate signal circuits are messed up (injector(s), tach, and speedometer). i would check all of the grounding first. is the harness grounded to the engine somehow? i imagine there must be some sort of ring terminal or something on there to ground it.

after that, i'd go to each individual circuit out of the three mentioned, and check that the ground wires in fact have continuity to the engine ground. are you familiar with a multimeter? i'm not trying to sound condescending if you do, lol i just dont know.

if everything is still on the up and up, and checks out, i'd move on to checking for continuity between:

...hmm, i can't remember if they run the tach and speedo signals through the ecu before they get to the cluster. i kinda think so... anyways...

-tach signal: distributor to ecu, ecu to tachometer
-speedo signal: vss on tranny to ecu, ecu to speedometer

is the ecu itself grounded? does your water temp gauge work?

psyguy23

thanks for the reply.

i am familiar with a multimeter. i have time tomorrow morning to test these things. but i do believe the distributor and vss are grounded because they are communicating to the ecu. this is evident by the positive readings i am getting from the hondata s300 programs which is registering RPM, ECT. i will do these tests though just to rule them out.

to answer your other question - the gauge cluster is not registering the coolant temp but again the s300 program via the ecu is measuring the coolant temp (ECT).

00b18b

Sounds like a missing thermostat housing ground, happen to me once.

psyguy23

so after even more troubleshooting it ended up being something in the harness itself. bought a new harness, plugged it in everything fired up flawlessly.