I replaced old tb with used new one as the old one had aftermarket micro switch glued to the side ported the new out inlet side and matched on the other didn’t go mad and go up to the butterfly, kept it 5mm back both sides engine doesn’t like it at all car will tick over from cold but as soon as throttle is touched it cuts out and won’t start after ive now taken the working switch off the new and put it on the old tb and all good any ideas why this may be happening any help appreciated
That's not a micro switch its a TPS if its an ABF (throttle position sensor). It senses where butterfly is in relation to the throttle pedal and tells the ECU so it can work out where the crank and pistons are etc, so it can set the fuel and ignition accordingly. As you can guess if its set wrong it will mess everything up, and same if its not working at all, it will throw everything out. Are you running an aftermarket ECU? What was the aftermarket TPS for? Maybe the wiring had been altered to match? Porting the TB will have so little effect on power/torque, I wouldn't worry too much, if the old one works then fine, plenty of other things to do that will have far more benefit.
haven’t tested the throttle position sensor only the micro switch which is good I did check check the wiring as a new plug was fitted for the micro switch and all good there thanks for the reply’s
If the car does not start, replace the throttle body with the old one. Start the car. If the engine fires up, good. Remove the TPS and fit to the target throttle body with the porting. Start the car. If it starts all good. Adjust the idle cam that has the throttle switch for idle. You want to adjust this, so that after a blip, the engine deaccelerates in a dashpot then come finally settles to ~ 800 to 900 rpm if on a Digifant 3.x ECU.
thanks for all the replies in the end it was a broken wire on the coolant temp sensor when I first swapped the tb’s over all seemed good but after a short drive the following day it was back to running rough swapping the tb’s over must of moved the wire so there was some connection there broken wire sorted and ported tb is on and running sweet thanks all