alexanderrx

I have been having only mediocer gas mileage on the highway (about 17 or so), where I used to get around 23-26. I was wondering what the problem was when I noticed that every time I hit around 3000 RPM, my voltage changed dramatically for a second.

Well, that was obviously the secondaries comming on, but I thought the secondaries weren't supposed to come on until past 3500 RPM or something. This gets me terrible mileage in the city, because every time I even put my foot on the gas a bit my secondaries come on.

There was a problem with my injectors a few months back, and I had a mechanic reset the computer and stuff, which fixed the problem. Did the reset cause my secondaries to open sooner, or is this normal?

Aaron Cake

iTrader: (1)

I doubt it has anything to do with the secondary injectors.

Does the voltage drop? How are your grounds and battery terminals? When is the last time the car had a complete tuneup? TPS adjustment?

NZConvertible

Actually I doubt it was. The secondary switch-on point is encoded in the ECU's firmware, and is not adjustable without reprogramming the ECU.

That's not how the staged injection works. When the secondaries come on, all four injectors are fired at half the pulsewidth the primaries were firing at before the transition. There is no sudden increase in fuel flow or change in AFR (unless something is wrong). You will obviously use more gas any time you put your foot down.

nukeall

i get shitty mileage too but why ?? i think my cars timing is off anybody in CAli do time adjusments ??? SnaP Yo Fingars!!!lol

NZConvertible

Very unlikely unless someone's messed with it. Buy or borrow a timing light and check it. It's a two-minute job.

nukeall

well hey im kinda new to rotary...but i mean how do adjust it (timing) ?? is the a bolt or something to turn ??? soo i get a timing gun for rotaries ??? and then what ??

NZConvertible

You get any any inductive timing light and check the timing as per the instructions in the Haynes manual or FSM. It's unlikely you'll need to adjust it, but if you do just keep reading.