TBI install for carbed festivas

[Safety Guy]

Interesting!

Not that you need to be told this, but K-cars '86 and later had TBI on their 2.2s and 2.5s.

Your point about GM parts is well taken, though.

Karl

[geezerstiva]

you and batstiva are on the top of my "do this for..." list

i am honored. thank you! you said your car ("Scrappy") had a b6. will you be able to adapt it for a b3 as well?

[Fordverde]

Question, how are you gonna limit the amount of gas that is going to be injected? You said that the TBI is from a 2.5L, and you have a BP right?? are you going to hack the ecu???

[FestYboy]

Scrappy is running a B3 intake and carb at the moment, so this will work on all B3/6 carbed engines.

fuel will be metered by monitoring of the O2 sensor, and fuel pressure. ECM will read O2 sensor and adjust injector pulse width to compensate. if it's still running too rich (i doubt this will be the case), i can start limiting the fuel pressure to the injector to as low as 9psi (normal range: 11-13psi). The 2.5 ECU is a learning ECU and tends to run lean anyway so i don't think it'll be an issue keeping things in check. i'm currently running a B6, but i have the means to test on both a B3 and B6.

[Fordverde]

Good, keep us posted so I may do it also!!!

[Axlander9289]

I'll be keeping an eye on this one. Hope it works out. Dudley wants TBI.

[FB71]

Scrappy is running a B3 intake and carb at the moment, so this will work on all B3/6 carbed engines.

fuel will be metered by monitoring of the O2 sensor, and fuel pressure. ECM will read O2 sensor and adjust injector pulse width to compensate. if it's still running too rich (i doubt this will be the case), i can start limiting the fuel pressure to the injector to as low as 9psi (normal range: 11-13psi). The 2.5 ECU is a learning ECU and tends to run lean anyway so i don't think it'll be an issue keeping things in check. i'm currently running a B6, but i have the means to test on both a B3 and B6.

keep in mind, ECUs have rather narrow range of adjustability, injectors don't work well below 2ms, and fuel atomization is adversly affected as pressure drops. The ECU can only tailor fuel delivery within it's lookup table. The O2 sensor can't over-write beyong the table limits. I'm not saying it won't work, I'm saying don't be suprized if it doesn't work as well as you hope.

[FestYboy]

^^ note taken. i'm taking all this into account and basing the validity of this project on the fact that the 2.5 likes to run lean in the first place, and that even though the factory regulator is set between 11-13 psi., the manual states that 9 is still an acceptable limit for the injector. if i have to go smaller yet, i can always opt for the 2.2L TBI injector out of some J bodies and the like. another thing helping the cause is the fact that the 2.5 head has a low VE% which equates to fewer CFM per stroke dynamicaly, vs. static swept volume.

still another option is the GEO Metro 1.3 TBI system, but i can't see any performance gains there for our 8V heads, pluss i'm not as familar with the Suzuki system.

mainly the goal here is to get a running vehical, reguardless of the milage. because as we all know, running is ALOT better than not running...

[Axlander9289]

How about fuel delivery? What are you going to do about a fuel pump? Inline? Are you planning on running a fuel return line?

[FestYboy]

yes, inline pump, and the TBI unit has a return built in after the regulator. easy peasy...

[Axlander9289]

...lemon squeezy

[Burnrate]

FestyBoy

Any progress on this one?
I know there are at least 6 or so carbs with the hiccups on here.
I am rebuilding an Aspire FI to put in mine but would sure love to see a fix for this.
And any MPG readings you get would be great also.

Eric

[getnpsi]

I'd love to tbi a high compression 1.6 as its wiring is independant, and more like a bolt on than a rewire/reharness/build a fuel system nightmare. Ehatever i decide im sure not putting the oem festiva carb and junk back on...

[FestYboy]

still trying to aquire a 91-93 S-10 ECM, as it has IAT as part of it's sensors. If i can't find one in the next week or so, i'll use a Fiero ecu and harness for the experiment (no IAT). only downside to this is the fact that i'll be putting my favorite Festy out of comission to do it.

but it's all for a good cause, right?

[collegeboi]

yup, good cause.

you can use my festi