Thread: B14-b13 step down harness issues

Im using a jk tuning step down harness with no luck. I have a 97 200sx ser and want to run a obd1 ecu, it runs fine on the stock ecu but when I plug in the step down and b13 ecu it won't run. I have 3 b13 ecus and 2 brand new step down harnesses and I have tried them all. The car gets spark but no fuel from the injectors, pump is coming on and running. I would hate to have to rewire this after buying the step down to avoid cutting up the harness. Thanks.

Ps I searched like crazy and found nothing.

So I'm using ecu pin outs for both ecus and this harness adaptor is wired completely wrong. WTF!

So far I have injectors 2 and 3 flip flopped and grounds going all over the place. Ignition signal leads going to grounds and all sorts of crap.????? Anyone else have issues with these jumper harnesses?

You should contact @JKTUNING

Already did and he said I may have ordered the wrong harness, but the package says b14 to b13. I got two of them and they both have the same issues. He is working on figuring it out so I'll keep this updated.

The odd thing is that the DIY jumper wiring diagram on the forum matches the jktuning jumper perfect. But if you look at the ecu pin outs for both ecus it's wrong....? Ridle me that?

I have wired b14s to run on obd1 harnesses but this harness was supposed to help avoid the hassle. Looks like I'm going back to the old days of loam splicing.

Ok so turns out this car does not like how the jumper harness grounds have been run. I simple added a few grounds and regrounded the ecu and now every is good to go.