hefftone79

1993 Civic CX
B18B1 (obd1),integra engine harness, P75 ecu

I have not started this car....ever. Weird crap keeps popping up like this.

Turn igntn to ON....Main Relay is buzzing (actually it's clicking but so fast it sounds like a buzz)..... CEL comes on after about 2 seconds and it sorta flickering so fast that it appears dim.....then about every second or two....the main relay clicks slighty slower, and the CEL gets even dimmer.....and it just sorta cycles like that. Also, I don't hear the fuel priming either (with no rear seat)

Unplugging the MAIN RELAY,...the CEL comes on after a second and stay lits, fully bright.

Previous owner had swaped in a Accord SOHC Vtec,....but was removed before I bought car...... the ecu plugs/wires seem to check out. Even has Heated O2 Sensor wires.

Any ideas....causing i'm really scratchin my head, and don't wanna go bald!

jztoy

Sound to me like you main ground on the back of the motor is loose. I had the same problem after I did my first swap. 2 weeks of pulling out my hair for a 10mm bolt

djsire

ditto1

i thouhg mine was tight till i noticed i could turn it by hand!

hefftone79

I checked that ground, cleaned up the contact points with some sand paper.

The CEL is not cycling anymore....it comes on for 2 seconds (flickering so fast it just looks dim).....the main relay is still clicking away and sound like a buzzer.

I also pulled the cap off of the MAIN and the solder joints look fine,.... tested the main relay using the procedure in the Helms manual adding +,- and testing for continuity and it functioned properly.

Fuel pump still does not prime, It did work when I jumped it out though.

nemeii

hey man i had a lil off that, so you might want to check out my thread and get some ideas ive got a feeling our problems are similiar.


https://honda-tech.com/zerothread?id=2353141

Kegan

Check all of your fuses, especially your ECU fuse. That's what caused my main to nuts.

hefftone79

ECU fuse is good to go.

The following is in reference to USDM_92-95_civic page 306 [pdf of (Helms section/page 11-116]

On a whim, i unplugged the main relay, and measure the voltage at the harness. (ecu is plugged in, key turned to on)
Dash shows solid CEL, battery, and oil lamps

[1] - to battery = 14v
[3] - to ecu (A25,B1)= 4.4v
[5] - to ignition = 13.5v
[7] - to fuel pump = no voltage

[2] - ground = <FONT COLOR="#FF4040">almost 6v</FONT>
[-]
[6] - ST switch (starter?) = no voltage
[8] - to ECU (A7,A8) = 4.6v

Now the 6v coming from the ground, i figure thats not supposed to be there...but where would 6 volts come from? And how/why would i be reading that from a ground wire to a seat bolt in the chasis?
The ecu voltage...i don't really understand if that is normal or not, because I was under the impression that power was supplied to the ecu via the main relay,...but then again, I don't have a great understanding of circuits or perhaps even electricity for that matter.

nemeii

two things...

try taking a look at your speedo sensor connection and harness plug (back of the motor under and to the left of the intake manifold if your standing in front of the car looking at the motor) going into the top of the transmission.

It might be corroded and shorting out your ignition signal power, unfortunately the connection socket it face up and water tight so if there was ever a coolant leak or a big puddle it sits inside until it evaporates out. If you have any doubts just leave it unplugged. you might want to check for continuity to ground which would indicate a short to ground confirming what i said about it.

secondly, one of the main reasons the relay ever fluttered on my civic like that instead of just actuating was because of a ground connection that breaks very easily.

behind the motor basically above the speed sensor but on the block of the motor is the thermostat, its got a bunch of 3/4 inch diameter coolant hoses coming off of it. But importantly on mine there is also a 10mm bolt going into the top that holds down a ground connector with two leads going off of it. Check to make sure the wires are still connected or if they are corroding apart or even still connected at all.

my car sat for three weeks because i couldnt find the problem, it was under the plastic going to the ground connector and because theres two wires if you tug on it, its still held by the other wire, youactually have to do a visual. on the individual wires themselves


let me know how it goes, laterz


the symptoms for me were, fluttering relay, solid check engine light that wouldnt flash a code,

xlasianizelx

im having almost the exact same problem..

my car was running, then it died.. now when ever i try to start the car, i hear a relay click / ticking near my glove box... ..

with the key in on position, there are no cel lights, when i try to start it... the cel light flickers and dims, as well as the relay clicking..

i tested my to see if the wires are giving any spark and it is.. so what else may be the problem?.... and where is the main relay located?

hefftone79

I did some trial and error work on my civic

I removed the instrument cluster (because it is not stock, it is from a civic though (has tach)). No cut up wires on the back of the cluster...Strangely, there is a yellow 4 wire plug (sorta resembles SRS) from car that is not plugged in, nor does it have a corresponding female on the instrument cluster.....this may add up later....
With the cluster unplugged, the Main relay did not buzz, but Fuel pump did not prime either, and obviously no CEL whatsoever.
So i put all that back together, and turn key, and the CEL flickers as the Main Relay buzzes, as before.

I remove fuse #15- 10amp [Gauge, warning lights, clock].....no CEL, No buzzing from Relay, still no fuel pump prime.

I replace fuse #15, and start to remove other fuses. One by one, and turn the key to on each time.

Then I remove fuse #24 -15amp [SRS unit (VB)]...this fuse was removable, unlike the next fuse (#25- 10amp [SRS unit VA]) which has the yellow tamper resistant retainer.

With fuse #24 removed, the Main Relay Does not buzz, The CEL is solid.....BUT, the Fuel pump does not prime. Also the battery warning light did not come on. I'm starting to suspect my ecu as being bad at this point, but I think there is also another problem in the car? What is on the #24 fuse circuit anyway? Could it be related to the unused plug going to my cluster?

EDIT**--Just found this out, the VSS is on the circuit are fuse #24 on SRS equipped vehicles, so I'm going to go back to that.


Modified by hefftone79 at 6:58 PM 8/28/2008

NastyHabitzCRX

are you sure you don't have a severly drained battery?

nemeii

97 civic ex, p75 manual ecu

Hey,

yeah so i thought it was the vss because a couple weeks ago i had the same problem, unplugged it and voila! started right up.... anyway a week later i turned it off at a gas station and it wouldnt start.

so now im back to the same issues, very dimm CEL light and oil pressure light mostly.... Also my SRS light is on however that may be an unrelated issue because i have a wire under dash that is coded blue/red stripe and in a haynes manual i have supposedly that can be an SRS lead, odly though i dont see, or remeber if and where it was plugged in.

occasionally when i fiddle about with the wires under the dash with the key in the *on* position i see the lights flare back up to normal but it only lasts for 10ths of a second.

Ive gotten it to the point twice where when i put it into the start position i heard the starter solenoid engage but not long enough or powerful enough to start, not even effort from the starter just the solenoid "click- clack" in the engine compartment(no it wasnt a relay theres a distinct difference in the sound and volume)

Ive pulled apart my entire dash looking for what appears to be the same problem as you. My battery ive been keeping charged courtesy of jumpers which is at 13.84 volts. So i know its not the battery. I can hear the fuel pump engage most times but sometimes the fuel relay just buzzers about.

***Its NOT the 10mm ground connection on the back of the motor.***

I not only checked that but I opened up the harness a bit and soldered new wires from the harness to the ground connector which i also resurfaced again for the hell of it, re-taped each individually and then also together, finally bolting it back down to the block.

Ive checked the tranny ground, valve cover ground and the ground wire going to the frame, all look sound and should be fine as its only been a few months since i resurfaced the contacts of all the ground during a motor swap, after which it had been running fine.

any ideas guys?? i think i am going bald... but from anxiety and frustration

hefftone79

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NastyHabitzCRX &raquo;</TD></TR><TR><TD CLASS="quote">are you sure you don't have a severly drained battery?</TD></TR></TABLE>

Positive, the battery is brand new, and kept on a maintenance charger, the engine will turn over like a champ. I know its not getting fuel (because the pump is not running), and I have not checked to see if it is sparking.

I've either got a bad ecu or a wiring issue somewhere.

shanetheman

If ignition goes on the main relay is buzzing and you have checked all your grounds you must check the main ground on those three little wires one is the brown with black stripes following another brown with black stripes and it’ll be a solid black wire and this is a ground on your thermostat those three wires if not grounded properly will not allow the fuel pump to kick back on

Maxcapacity

Old thread being revived but to anyone that may have this- this type of situation usually leads to a bad capacitor inside the ecu I have found when the main relay is buzzing and no trace of faults anywhere else to be found.