i want to convert my sunbird engine which has Throttle body injection (TBI) to multi point fuel injection (MPFI) and i was wondering if there were any differences in the block between these 2 engines or any differences that would prohibit me from doing the swap. Both engines are 2 liters. Any help in this conversion will be good, and if anyone has done it before please help me out. thankyou
is there a ckankshaft position sensor mount or hole on the TBI block?
Hi, Sean.
This is an easy swap as far as replacing parts. Find a pfi 'bird and get the fuel rail, intake, lines, cables, brackets, and any other parts you need. The problem is in the control module. The Sunbird control module expects a crankshaft position sensor. Your engine probably does not have one. Nor does it have a place for one, or the notches on the crank to generate the signal. You could use an ecm from a vehicle with a distributor, but then you'd have to reprogram it for the fuel and spark needs of your engine. The easiest way to get around this is to get a crank and block from the pfi engine.
-->Slow
yes i already have all of the mpfi sunbird parts available.....actually i have the entire engine with a burnt piston and a brand new TBI crate motor sitting in my garage (long story) and thought swappinng all the mpfi to the tbi block would be a cheap alternative to rebuilding the mpfi. so u are saying that the tbi has no place for the crankshaft position sensor?
thankyou
Check to be sure. None of the TBI engines I've ever seen have had a place for the crank sensor.
-->Slow
really..ok.....well if i cant use the block....will other pieces work such as the pistons, rods, and head
and would it make since ti run tbi rather than pfi......ive read that tbi makes less horspower but ive seen a lot of people using it....are there any benefits?
Benefits to TBI?
Sure. It's reliable, cheap, and plentiful.
You can use the block, but it will need to be machined for the crank sensor. The place where the sensor goes is usually cast into the block but the holes aren't drilled. Don't plan on drilling the holes by hand, though. Contact a machine shop and try to describe what you're doing. They probably won't have an idea what you are asking about over the phone, so you may need to be patient and work with them. You'll have to disassemble the engine so you can clean out any metal chips after the hole is bored. On reassembly you can use the crank from the MPFI engine which will give you the correct toothed wheel to work with the MPFI ecm.
Honestly, check the side of your crate engine. You may get lucky.
-->Slow
thankyou for your help....i really appreciate all the things you have told me
