TBIThrottle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
I just finished installing a Holley pro-jection TBI unit on a 305, I used a '93 pickup 350 intake manifold to make bolting up things easier, the TBI fitted nicelly there, just had to enlarge the bores a bit since the holley barrels are bigger than the chevy's.
I'm experiencing a ecm calibration problem, when the motor revs up under heavy load it stumbles a couple of times, like hicups then keeps revving fine and pulls very well
I have tried going lean then rich in the main fuel knob but seems like it won't go away, any suggestions? anybody has used a similar setup?
I'm not using a O2 sensor, so I can't tell if it's lean or rich when the problem happens.
Is that a Holley ECU? Does it run open loop with no NB02 sensor? I saw an early Edelbrock TBI with its ECU on a 350 in my buddies shop. I believe that too was open loop only. It was retrofitted on a 1977 Olds Cutlass. Something tells me the fuel mapping did not have a VE table and was pretty archaic. There was a controler of sorts laying on passanger seat. Spark was a standard mechanic distributor.
yes it is a holley ECU,
I solved the problem today, it was my fault, I was too lazy to install the ECM power lead using a relay to get juice directly from the battery, so I installed a wire from the HEI hot terminal to the ECM, I beleive this gave a dirty (pulsating or something) to the ECM making it behave weird, so I followed the instructions and wired it using a relay, now the power goes directly from the battery to the ECM, all problems gone, even I had to lean all the parameters, maybe I wasn't geting full voltage to the ECM, now the motor runs great, never did so well with a carburator and I tried several, from the ugly 2 barrels ( both the old 2MC to the.. I forgot the name of that Q-jet sawed in half) to a well tuned and modified Q-jet, this TBI really works nice and calibrating it was a breeze, I think it would work better in a 350 since it feels a bit overcarburated, it flows 625 CFM wich is too much for a stock 305, but runs great anyway.
