Richening up my TBI

[marcoze]

I got an 89 Mini with the 2.5 TBI motor and i was wondering if there is a way to Richen up the fuel on that sucker. I know carbs like the back of my hand.....but not this TBI.

[Una]

Gotta edit the calibration.. But nobody has documented any of the TBI cals, so you'd be blazing your own trail.

[allmotor]

why??? the ecm does just a fine job controlling a/f mixture for the engine in it's stock form. now if you mod the cam and compression ratio, then try restricting return line, that will fatten up the ratio. or disconnect ox sensor, it won't go into closed loop and will give you lower fuel milage like you want to do.

man if you are still thinking carbs, you must be ancient dinasaur or been driving a small block chevie in camaro for tooooo many years.

[marcoze]

well as an experiment i was going to throw a T1 on there and pipe it into the TBI just to see how long before it would explode.

And sorry about thinking carbs.,....just been too busy building my 555 Cu. In. BBC Nova to brush up on my EFI.

[Una]

I figured you wanted to just fatten up the WOT tables, which don't use the O2 sensor to take advantages of some mods you may have done. I doubt the TBI injector could ever flow enough fuel for a turbo.. It's really not that much work to swap on a turbo intake and swap in a turbo wiring harness. Then your not doing any screwy fuel adding.

[marcoze]

Quote:

Originally Posted by Una I figured you wanted to just fatten up the WOT tables, which don't use the O2 sensor to take advantages of some mods you may have done. I doubt the TBI injector could ever flow enough fuel for a turbo.. It's really not that much work to swap on a turbo intake and swap in a turbo wiring harness. Then your not doing any screwy fuel adding.

This i know (Swapping)....however i have the oppertunity to purchase not one....but 2 89 Turbo minis in exellent Shape (I shall horde them) and just wanted to screw around with my Beat one i have now. Besides the fact that i have a Home Made Flamethrower setup on my car....and the 10ft Flames are cool but larger ones (Short of going propane) would be awesome.

[Una]

I have a '90 Horizon that I have kept TBI. It makes a reliable backup car that runs happily on cheap gas and gets great mileage. If it were me, I'd leave it TBI, if it's auto convert it to stick and it'll be significantly peppier (try to use a MT with a 3.85fd)

[Cooter]

One thing I always wanted to try when I had my old TBI Horizon was add a second O2 sensor, have one in the exhaust and another exposed in the engine bay, and have them wired into a switch in the cab. have the exhaust one for economy, then with a flip of the switch, the ECM would read full lean (reading from second O2 in engine bay) and richen the mix. In theory it should work, but before I could try it, I wrote off my Horizon.

Good luck,

[RPMurph]

do they sell larger injectors for TBI cars? i thought i saw them somewhere....maybe they were smaller.....but they were like 8 or 10%