my cousin has a '91 ex 4dr. thats throwin cel code 4, crank angle sensor
it will not rev past 3000rpm
we changed the dizzy and ecu with others that were known to be good and checked the timing but no luck.
the only other thing i noticed is that it has the mpfi head but it has a d15 block.
i thought that all ef civic/crx's with mpfi had d16a6 blocks.

i'm assuming that someone replaced the block with a d15 before my cuz purchased it
(about 2 weeks ago) and didn't replace the timing belt with the correct one.
i guess a d15 uses a different belt than a d16.

how can i tell which belt he needs and which belt he has?
could this even be the reason?? please help.