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How does b16a1 Vtec Switch

Posted:
Wed Mar 03, 2010 11:43 pm
by Ylts
Engine found 89-91a 4 gen,
Dont have VSS sensor, how ECU know, how fast car is moving?

Posted:
Thu Mar 04, 2010 12:08 am
by Dippin_EG
swap it out for a 5th gen OBD1 VSS. im pretty sure thats how it goes

Posted:
Thu Mar 04, 2010 6:42 am
by Ylts
I intrested how it work in factory

Posted:
Thu Mar 04, 2010 1:48 pm
by forcefedEG
if the engine is a 88-91 it will have a cable trans, and cable trans have mechanical speed sensor, (but a electronic speed sensor will fit in a cable trans if you using a cable to hydro conversion) 88-91 cars have cable speedo, where as 92-95 have a electric speedo, but on the cable speedo cars i believe the speedo backfeeds to the ecu and thats how u get the speed signal for the older engines...

Posted:
Thu Mar 04, 2010 1:51 pm
by forcefedEG
but if your asking how the electronic speedo works... threre is a "speedo ring gear" on the diff in the trans and there is a "pinion gear" on the vss and the two mesh together and as the car moves that generates a voltage signal to the speedo/ecu....

Posted:
Thu Mar 04, 2010 3:25 pm
by Ylts
I need info for my mini me swap

Posted:
Thu Mar 04, 2010 3:38 pm
by forcefedEG
your title said "need answer b16a1 Vtec Switch" not sure i understand about your mini me question? unless u meant u fount a oil pressure switch from a b16? in that case there all the same...?

Posted:
Thu Mar 04, 2010 5:50 pm
by Bobec
We did the mini-me swap on a 4. gen civic(d16a6), and now he wants to know, how and where to get the vss signal, to get the vtec to work, at the moment he can only switch vtec on manualy...

Posted:
Thu Mar 04, 2010 6:00 pm
by forcefedEG
i think the speed signal on the ef's come from the speedo thru the wiring harness on the back where it plugs in, your best bet would prob be to get a pigg tail harness online and adapt it to obd1
http://www.streetlightz.com/OBD0-to-OBD ... 26C31.aspx and then use like a p28 or p08 ecu but idk how much u want to spend, because the only obd0 vtec ecu is a pr3 jdm b16 (wich is super hard to find now days but there out there) and that requires you to wire two o2 sensors wich is a pain... the conversoin harness is self contained and not hard u jus need a 4 wire o2 and an obd1 dist. hopefully this helps?

Posted:
Thu Mar 04, 2010 7:09 pm
by Bobec
He already has the harness to obd1 and the car runs with p28 ecu... our only problem is, that the speedometer runs with gable, but on a 5.gen. civic electronically(with vss sensor). And why this thread... we thought, that the only civic from older gen. that has vtec is the b16a1 and the speedometer is also with cable, somehow the siglal is being sent to ecu, that the car moves... but how

, the vtec does not work when the car stands... for now he just has a switch that gives the solenoid 12v and vtec works

Posted:
Thu Mar 04, 2010 7:18 pm
by forcefedEG
ok... i think im understanding lol, on the older ones from the best i under stand the cable turns the speedo but then something in the speedo sends a signal to the ecu as it oves faster, what would cause this not to work im not 100 percent sure. idk if any fuses have anything to do with it or not... everyone i know who has done the harnesses has never had any problem like this, you could always get a electronic vss and pin the wires in on the adapter harness as worse case senario... bun the your speedo wouldnt work... id try looking in a repair manual and tracing some wires down for signals or check all your grounds...

Posted:
Thu Mar 04, 2010 7:22 pm
by forcefedEG
i belive the way the adapter harness work is that they pin out so that your signals are sent to the right places for the obd1, because a friend made his own harness an had to tap into a wire coming out of his speedometer this is the only reason i know theres some sort of signal there...

Posted:
Thu Mar 04, 2010 7:26 pm
by Bobec
So he could just try swapping out hes old cluster with 4.gen doch vtec one and get the signal from there and send it to ecu?!

Posted:
Thu Mar 04, 2010 7:29 pm
by forcefedEG
maybe that would work idk 100% but ive been told the sir b16 clusters are electronic speedo... but the people i know that have done them just use usdm cluster... did u make sure the vtec oil pressure switch is grounded on the back of the block where the harness grounds???

Posted:
Thu Mar 04, 2010 7:35 pm
by Bobec
We`ll try that, and also get a manual for the wire harness. Our only problem was the vss sensor! Thanks
