Rb25 s14 ecu not receiving speed sensor signal

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JkRB25s14
Posts: 4
Joined: Sun Dec 03, 2017 3:54 pm
Car: Rb25det series 1 s14 240sx

Post

Hi guys, so my ecu isnt receiving a speed signal.
Its an rb25det series 1 in a 95 s14 with a z32 ecu.

From my understanding the speed sensor goes from trans, to fusebox, to speedo, then finally to ecu. 

Here's my issue, my speedo works correctly, so it must have continuity from trans to cluster. So i checked continuity from the connector that plugs into cluster to the ecu pin 53 (speed sensor) and it has continuity. I dont know where to go from here?
And with no ecu speed sensor reading i believe it makes my car go into a limp mode and it ends up barely running at all.


JkRB25s14
Posts: 4
Joined: Sun Dec 03, 2017 3:54 pm
Car: Rb25det series 1 s14 240sx

Post

Ok guys so heres whatsup, this is a long post fair warning.
i have a series 1 rb25det in my 95 s14. I got it a year ago tuned it on a z32 MAF and a z32 na ecu with nismotronics, found out it had a bad turbo, but it was reliable, no hiccups at all.
So i pull motor and trans, planned on building it but didnt, just inspected block without pulling everything out, it had compression. I lapped the valves, new head gasket, rear main seal, thermostat, oil pan, arp head studs, water pump, oil pump, timing belt, cxracing exhaust manifold, freddy intake, q45 throttle body, wiring specialties oem main harness, precision 5858bb, id1050x injectors, precision 38mm wastegate, radium fuel rail, SARD FPR, warlboro 255 wired on its own relay, new fuel return and supply from tank to engine bay, fuel filter, battery in trunk, oem z32 MAF since the original was a knock off replacement.

So with all that said i get it tuned it makes 470whp 350tq. Runs damn good, until its warm.
Once its warmed up it stalls out, on the data log everything looks good with the ecu, the only thing that happens is the MAF voltage drops and the rpms just drop even when throttle is still applied.
You can start it back up and its a 50/50 shot if its running super fat with afr at 9 at idle, or its normal. So i can take back off and lay into it and it does a normal healthy pull and then again it hiccups again. And it constantly will do it.

Ive tested the MAF already its good, TPS is good, VCT is working, ecu is getting VSS signal.

The only thing that drops out on the log is the MAF voltage and rpm like i said. Guys im so lost at this point.


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