blackrotary23

the cas has been removed. i know how to line it up and all but how do i find exact top dead center??? i cant go by the pulley because that doesnt work for some reason. is there a method to finding it? plug holes or something? please help....this car is eating gas and fuming badly.1991 n/a rx7

beefhole

iTrader: (29)

Why does the pulley not work? Does it have the markings? You line up yellow on the pin. Then line up the dots on the CAS and "stab" it in. It should sit around center of the slot where it has room to adjust.

blackrotary23

ive tried that, but it doesnt seem to work properly for some reason.

beefhole

iTrader: (29)

Then it may not be a timing issue. Have you tried pulling codes? Sounds like a limp mode. Bad OMP (you just lost the ECU also ) or bad water temp sensor.

blackrotary23

the car is a 91 but the engine came from an 86. everything hooked up except the omp. there are no connectors for the mechanical one. could it not being plugged in cause it to go into limp mode? how can i ground it?

RotaryRocket88

iTrader: (7)

If the ECU is S4, there's no limp mode. If it's an S5 ECU, then unplugging the S5 electric OMP immediately sends the car into limp mode. The electric OMP would need to used or plugged in off to the side.

blackrotary23

thats all i needed to know, THANK YOU!!

blackrotary23

cant it just be grounded some how? like looping the power in with the car and grounding the ground wire???

jackhild59

iTrader: (7)

Nope. The ECU needs the MOP to communicate with it. It does NOT have to be installed on the block, but the electronics need to work or you will exist in Limp-mode HELL.

There have been several half-hearted attempts to make an emulation circuit to eliminate the MOP but the right way to do this is to go to an Rtek modified ECU. They have the ability to eliminate the MOP code from your ECU and can even provide an ECU that is programmable.

There is an Rtek forum under the Engine Management heading: https://www.rx7club.com/rtek-forum-168/

Good Luck!

blackrotary23

thanks, that fixed the problem. then the main relay went out, go figure. fixed that, now it runs great.