engine stalls in run position

[artwood789]

I swapped a 94 1.6 16v engine into a 87 sammy. purchased redone wiring harness and when I turn key to start in fires and starts to run ,but as soon as you let key go to on position it looses spark. any troubleshooting suggestions

[jtgh]

apply a volt meter to ECU.
power pins.
you are losing power to ECU or loosing the CAS signal from the Dizzy.
so you have a 94 16v and a 94 16v ECU but what about the 94 16V
wiring harness? no?

what do you really have.?

its a frankenkick but what flavor.

the orginal 94 has a main relay, that keeps every thing powered up. I bet it's missing, right?

[artwood789]

Thank you for replying;
Yes I do have the 16v harness. I also sent it and the original suzuki harness
to Trail tough and had it rewired for the 16v. It does have the main relay on it as well as modifications to my cluster for tach and vss. I do not have a ground wire to the dizzy. I believe I grounded that to the firewall if indeed it is that wire. What do I need to check for the signal from the dizzy when in run position. Also can any sensors cause this or will any codes show up.

[jtgh]

you have power to the ECU wired wrong.
this drawing and a volt meter is all you need.

http://carfix.stufftoread.com/ECU/92...-schematic.pdf

see notes, that say HOT at ALL times, yours is NOT HOT.

this is the simplified dwg. if need the full deal. holler.

[jtgh]

check the output of Main relay, if it drops with key at run , that is the problem.
work back from there.

ECU holds MAIN , energized with its coil driver.

[artwood789]

I checked power according to the schmatic This is what I have

blk/wht wire at ecm is hot at start/run
blk/red wire at main relay is hot all times
blu/blk wire is hot in start and in run mode

[jtgh]

auto or manual , you never said.? (harness is different btw. each)
also is ecu auto or manual ? pn? last 5 digits will tell.

blk/wht wire at ecm is hot at start/run ,>>>> ok
blk/red wire at main relay is hot all times >>> ok.
blu/blk wire is hot in start and in run mode>>> ok.


a1 = 12vdc
a2 must be wired correct if manual. (clutch)
a22 must be wired correct if auto. (park lockout)
a12 and a13 hot. in run or start.


its either cutting spark or cutting the fuel injectors when you are releasing the key ,
or
the tranny lock out logic is killing it all.

one more condition.
A8 must see the spark after key is release or it shuts down.
fuel is cut as soon as a8 goes dead. (fire safety feature)
that noise supressor has 1 more reason for being there.
it has a 2k resistor inside the creates spark feed back to ECU.

this should get it spinning.!
tell more. as you learn more.

cheers.

[jtgh]

franken jeep, sounds like fun. 125hp in a SAMMI.
scootn.

[artwood789]

I did the wire checking you showed me. I do not have any voltage at the A8
terminal at ECM in start or run.How do I check this out. My ecm is for a MT, at least the last 2 digits say MT..The other one I have that I am not using says AT at the end.I believe it is wired correctly. I have to have the clutch pedal depressed or it will not crank.I do not know about the A22 terminal. What should it read. Most likly the Brown (tach) wire from the noise filter to ECM. I also may be wrong on voltage. Should the A8 wire have 12v at run or
continuity from the noise filter. Schmatic seamed to show it as a ground

[jtgh]

a22 is for auto only skip that.

a8 must be 12vd, or ECU will shut down.

it sits at 12v and when the coil fires, it pulses low for 4 milliseconds (very fast)
the grounds are for the filters.
the resisor inside supressor is 2000 ohms.
it must be present or no run. (supressor ckt).