Amberlyscramble

Hey guys I got an 88 crx HF with a dohc zc swap. Ran fine til yesterday when it wouldn't start.
At first you could hear the starter crank. But not the fuel pump kick. After about 20 minutes I got it to fire. Somehow i really don't know what I did... Let it run for 15 minutes. Then when I drove it. The check engine light came on the light on my Ecu code light was soild red.. My fusebox under the dash started making a buzzing noise and my car died as if I had turned it off. I rolled it back into its parking place and waited til the daylight came. When I went to my car in the morning and tryed to turn the key. Nothing happend. No clicking are anything.
I barrowed my girlfriends battery. Nothing.
check grounds and wiring. Everything looks good.
my question really is if the starter will crank with a bad main relay or bad starter relay.
IV checked all my fuses and even replaced most of my under the Hood fuses box fuses. Just because.
Doses anyone know what the relays that plug into the underdash fuses box are?
if anyone has diagrams or something
That's be great.
also if u guys would like pics let me know and I can shot sum in the daylight.
thanks.

Amberlyscramble

Do crxs and other efs share the same main relay? There's no crxs in the junk yard. But tons of 4 doors

90civic-ZC

A lot of the fuses under the driverside dash is for lights, radio and ect. With a known good battery does the car lights work? but the engine and everything else does nothing? If all your fuses are fine but your ECU is just a solid light that usually means the computer is fried. and you're sure you're throwing no codes except for the code 0 solid light?

90civic-ZC

Forgot to say, check the ecu ground on the thermostat housing, I'ver heard of some people having problems with it not grounding right or the connection is loose.

redlinetuning

Under the hood fuse box, remove the ECM F/I fuse for a minute. Put it back, and see if the CEL goes away.

90-2001 Integras, 88-2000 civic, 90-96 Accords (I know for sure) share the same Fuel Main relay. Not so sure on the 86-89 Integras, pre-90/post-96 Accords as I've never had to dig out the Fuel Main Relay. I would suspect that they share the same part number.

The Fuel Main Relay is labeled "Mitsuba", and it is grey in color, above the fuse box on the left side adjacent to the door. It's a bitch to get at in the EFs.

90civic-ZC

If you turn the key and nothing happens, not even the dash or radio turn on then it's your ignition switch but if everything does turn on I would also try resetting the ecu like the previous poster said.

Amberlyscramble

Yes the raido and lights and highbeams all work. I bench tested my starter and it cranks fine. But not when I turn my key. I'm soon stumped. I'm about to go spend 60 on a main relay. But I honestly think my starter would crank even with a bad main relay...

Amberlyscramble

Oh and the relays I was trying to figure out in the under dash fuse box was hazards and defrost relays. Nothing important

4drEF

Why not just take out the main relay and resolder it?
and yes, the 4door has the same relay. You can
New would be nice, but since it seems that you are just throwing parts at it instead of doing a proper troubleshoot then I would get a couple used ones first.

https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/checking-main-relay-pics-2535047/
There is a LOT more info found where you search.
Common problem.

The fix
http://www.youtube.com/watch?v=kY_GnVwOF9U
Just open it up and resolder everything.

Amberlyscramble

Thats a really good idea. I'll look into that.

Would my starter crank with a bad main relay?

Amberlyscramble

And and what's proper troubleshooting?

4drEF

Yes.

Easy check for MOST main relays is to put the key in the ignition and turn to 'ON' (the position just before cranking the engine).
Listen for the fuel pump to whir for about 3 seconds. During this time, the check engine light (CEL) should be on and then go off.

Amberlyscramble

Oh well I'm starting to think main relay ain't my problem then. Cause my car won't crank at all. Any other ideas? Or trouble shooting tips

4drEF

Solid CEL is either blown ECU or bad ground.
Buzzing noise is the main relay and usually happens when it has a bad ground.
Both the ECU and main relay have the same grounding point.
As "90civic-ZC" already suggested, make SURE your thermostat grounds are good.

Also, if you don't have a solid ground going from the battery to the transmission, then your starter won't work AND you won't have ground to the ECU and main relay.

Check the thermostat ground.
It looks something like this

If they are good, then take a set of jumper cables and connect one cable to the NEGATIVE battery.
Connect the other end directly to a bolt that connects the transmission to the engine.

OneBadTurboCRV

I keep reposting this information and it's getting to be around 5 threads deep... Fun, fun.

https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/crx-ls-vtec-wont-rev-past-3000-rpm-2928827/

Amberlyscramble

Thanks guys. It was a 50 amp fuse.

4drEF

I never understand this.
So irritating.

OneBadTurboCRV

I 100% agree... It makes me want to stop participating in Forums period. The ignorance is amazing... Also, if people think members on here are full of themselves they should try some of the other forums I frequent... Like AR15.com for instance...