Topic: Modding a '90 TBI motor

[eodjeep]

I'm swapping in a different 2.5 to replace one lost to fire and water damage.  Since I'm going through he trouble of putting in a new motor I was thinking of freshening it up (re-ring, bearings...).  While I'm in there I was considering what mods I could do that don't cost an arm and a leg but I keep bumping up against questions of what will work with the primitive TBI set-up my '90 has.  Many posts seem to feed my feeling that the TBI computer cannot adjust for mods.

Is this true for a cam?  Will the stock computer have the brain and injector capacity to feed in more fuel to keep a proper mixture?

IF it can, did BoringDave ever get his cam ordered and in and is he still around?  I'd like to find the best cam that I can "drop in" without machine work.

[Jeffy]

If you're not dealing with emission tests then I'd probably gut the Renix and use a split-second or some other aftermarket computer to run everything.  Going with a big cam will more then likely screw up emissions.

Though if there are no emissions tests then I'd just yank the old engine and swap something else in. You might want to consider dropping in a 4.2L or even a 4.0L HO.  A TBI 2.5L is already starting 20 hp down from a MPFI and about 22 hp down on a 4.2L.  Or else just go with the tried and true SBC.

[chardrc]

2.5l tbi responded well to the bored out tb sharp gave to me. Never did any internal work to know how it would respond to a can. The injector and fpr are the same style as the Chevy TBI engines used so you do have options to get more fuel in.

[Mnkyboy]

Boring Dave has an MPI 2.5l,as far as i know he didn't swap cams as of the last time i saw him.

On my 89 TBI i ended up converting to MPI before i started modding the engine.