Fasian

Car 89 CRX
Motor B16a Turbo
ECU Hondata

In turn 3 at langley speedway my car went completely dead instantly. After doin some checks Im not getting fuel or spark. The main relay does not click and the check engine light stays solid. I cant jump for codes and hondata will not connect to laptop to pull codes which leads me to believe the ecu isnt getting power. Now all of this points to main relay or bad ground for relay. I replaced the relay with two known good ones and re grounded the ground. I tried a different ecu with no luck and put the hondata ecu in a different car and it worked fine. Anyone have any suggetions.

P.S. the car does turn over.

Fabrik8

If the main relay isn't engaging, grab a multimeter and start finding out where you have power and where you don't, or if you don't have ground continuity. It should be a fairly simple fix, but you aren't going to solve the problem by crossing your fingers and replacing parts that haven't been diagnosed as faulty.

I'm going to say the exact same thing on this forum as long as people keep doing the exact same behavior.

Fasian

Im starting muiltimeter tests tomorrow will post my findings just wanted to get the thread rolling because i normally dont get responses this fast

Laserjock

Inside the engine bay fuse bank, look for the HAZard fuse. This shares the same 12V as the ECU

Yes, honda did stupid stuff back then too.

Fasian

ok muilimeter was effin up so all i had was a test light til i get a muili meter so i tested the ecu fuse under the hood and got nothing i will post muilimeter results when i can. also the hazard fuse was fine thanks

Laserjock

Start at the ignition switch is all I have left.

JustaGSR18

your car is obd0 so I am going to assume that you are using a obd0 to obd1 conversion harness.. I ahve seen these go bad countless times the design is terrible. I have done a few conversions to true obd1 plugs and they solved every issue. It takes alot of time, patience, diagrams, and some soldering skills. but well worth the effort as long as you do it correctly. if your main relay is not clicking, your laptop will not read your Hondata and the hazard fuse is good (replace it anyway just to be sure) and when you turn the ignition on all the dummy lights come on then it pretty much leads to the conversion harness. Like I said I have seen issues with these harness before.

Fabrik8

You must have bought really horrible quality harnesses. I had a zero failure rate with all of the ones I made, and I made a LOT of adapter harnesses.. I don't it anymore, they were brutally tedious to make.

JustaGSR18

I am reffering to most of the ones sold online, they break very easily. whenever I got my hands on any obd0 car I cut the obd0 plugs off and soldered obd1 plugs in place of them. I have also done this on a few friends cars and this method has had the best turnout for me.
tedious, yes.. worth it, hell yes

sweethatch1866

Im having the same issue with the s300, only other thing I came to is I git spark to the spark plugs when they are out the hole and grounded but not when they are installed. I sprayed a lil starting fluid in the intake and it didnt even hit. If they were sparking it should fire the starting fluid regardless