Ive been doing this swap for a while and i really just want it to work. I did a full engine swap in my 2001 accent 1.5 and I have a 2000 elantra 2.0 in it. I have a 02-03 ECU (ill find out soon) with a 2002 1.6 accent harness rewired to match the ecu and all the 2000 sensors and the mc and ec plugs. Crazy mix up.. Everything is wired, The only problem is there's not enough power (about half the required) going to the fuel pump relay fuse, and the ecu01 & 02 fuses in the engine bay fuse box aren't getting any power. So my fuel pump barely works, and I'm getting no spark and no injectors.. It turns over and everything else seems to be workin fine. Any ideas on how I can fix this or even something to go on so I can give an auto electrician a chance to fix it? Thanks

 

Large wire, fused separately near the battery, to fuel pump. Relay switches that wire. Abandon the stock wiring if there's too much resistance.

 

Thanks for the response. By near the battery do you mean spliced to a wire close to the batt? Then where do I splice the other side, the power wire that feeds the fuel pump relay? Sorry for the noob questions, trying to learn this stuff!

 

Any time you add a power wire, you want a fuse very close to the battery. Preferably within a foot to 18 inches, ideally fused right at the battery terminal. The shorter the wire between the fuse and the battery, the smaller the risk of burning your car to the ground. Not that you would, but it has happened that unfused power wires cause car fires.

 

As stocker said, for the purposes of science, I'd run power to the fuel pump and the ecu fuses, then see if anything changes.





How did you disturb the ecu fuses anyway? Most fuses and relays in the engine bay get 12v all the time, direct from battery. Usually what is missing, it the impulse from the computer to utilise this power.

 

Okay thanks I understand now. I really hope there's nothing wrong with the ECU or the connection to it. I actually had Hotblue02 send me a new ECU with a premade wiring harness for my specific set up. I haven't heard from him in a while so this is where I'm stuck ATM. Next thing I'm considering is if I can't find a simple way to fix this I might just get another harness from another 01 accent and re-pin that one to another ECU, and fab the connectors, just in case the ECU I have now is dead (but that's improbable since I bought it working). I would much rather find a way to not have to go through that though.



Adding on to your comment about the ecu pulse, if my fuel pump relay is getting around Half the power it should does that say anything about the communication with the ecu?



Thanks for the advice and opinions so far!

 

That would imply bad wiring to me. Test for power all the way up the line, you might have a ghetto short circuit or bad earth somewhere.

 

Ill get right on that! Thanks, ill update with my findings.

 

Alright so I went and got another ecu, exact same, and still nothing. It almost seems like the ecu isn't getting any power to it. I tried hmaservice and couldn't find the wiring diagram.. Does anyone know where I should start trouble shooting? Any help appreciated I'm so stuck here.

 

Been double checking the wiring on the ecu and it seems fine.. Honestly the most stressful thing I've ever dealt with. I can't find a garage in my area willing to look this over. I need someone's help really badly.. I was abandoned by hotblue02 who had made the harness for me so if anyone with good knowledge of beta swap wiring that could share with me some trouble shooting possibilities that would solve my no-powered ecu that would be amazing. I have no spark, no ignition, no CEL. Just turns over..