Vtec not working

[b18delsol]

I have a B18c5 OBD 2 in my del sol and i am running a B16 obd1 ecu. it was running find for a month and now vtec suddenly don't work anymore. Anyone have any ideas why the vtec doesn't work.

 

[E_SolSi]

oil

 

[b18delsol]

So you think it is the Oil? Well the car has been siting inside a garage and hasn't been driven for over a month. I guess it has been over 3 months since the last oil change. So old oil makes Vtec not work?

 

[xj0hnx]

No, to little oil will not engage vtec. Also tempature, speed and ECU rpm point all effect whether or not vtec engages.

 

[b18delsol]

now i am more confuse. temperature is fine lil under half way. ecu is a B16 ecu and rpm gauge doesn't work at all( don't kno why). If all that is a factor why did it just suddenly stop stop one day. Vyec worked last night but this morning it stoped working

 

[xj0hnx]

The motor/ECU have to come together on a couple points to engage vtec.

Tempature has to be 140 degrees(I believe maybe 120)
RPMS, have to be at whatever your ECU is set to
you have to be going forward at 20mph
and oil pressure needs to be XXpsi

If for some reason your rpm signal is not working, than you will not have vtec, same with your speedo.

 

[Incredib1e]

you probably wired it up wrong. Thats what happened with mine. It worked fine for a couple days but the speedometer and even my reverse lights were not working. Within a couple days I could not even get it started. I ended up frying my ECU, had to switch to OBD1, works a hell of a lot better now.

 

[b18delsol]

when i wire the car up everything plugs right in. i don't know where i can go wrong wit the wiring. How do i go from OBD2 to OBD1? is it by switching the wiring harnest and distributor to OBD1?