hey guys ive got a couple question. im building a motor for my 1993 gmc sonoma. its a 4.3 tbi with heads and cam. the cam specs are lift I .479 Lift E .488 duration I .210 Duration E .214 LSA 112.

the problem im running into is in 1993 gm gave the 4.3 5 speed s-sereis bastard ecu's (number 16190402) that no one can burn chips for and they incorporated the VSSB, knock module and electronic spark controller into the ecu. so i cant just simply do a ecu swap i would have to do a harness swap.

i was planning on keeping it tbi for a few months so i can finish my mpfi manifold and get some money saved for the mpfi ecu.

i am wondering what kind of idle/drivability probelms im going to have on the stock tune with the new camshaft. i know the system is going to run rich due to the aftermarket cam pulling less vac, and an s-series guy told me to just turn the fuel pressure down to try and lean it out a bit. but im worried about it leaning out up top if i do this. but if i dont mess with the fuel pressure im worried about cylinder wash and flooding.

you guys seem prety knowledgable in the tbi dept so i figured id get your input

thanks
-mark

 

The Jeep Barracks - Building an Adjustable MAP Sensor

Before I got into burning my own chips, I built this circuit and used a pair of 350 injectors on my 305 with a head/cam swap and full exhaust.

 

thanks for the reply, it looks like that along with an adjustable FPR should get me by till i can ge the mpfi done

thnaks a milion
-mark

 

anyone else have input?

 

What does it look like? What do its connectors look like? (pics would help) The solution might be as simple as using a different, more commonly used mask (thing thats programmed on the chip) if its a standard truck PCM.

 

its a 3 plug ecu 2 32 pin plugs and a 24 pin plug