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Gen 4 swap not running. No spark at coils, help plz :)

Sun Jan 26, 2014 4:32 pm

hey all,

so I've put a gen 4 motor into my 1992 alltrac celica.... i presume its very similar as the mr2 gen 4 swaps as well with minor differences.

anywho I've hit a deadend as I cannot get the car running. Hoping I can get some help how to sort through this headache.

I had tweakd performance do the wiring harness and relocate the fuse box into the cabin.

The car cranks over but It does not run. I checked the coils connectors to see what I was getting and here are my findings on the 4 pins in the connectors:

1. Good ground
2. 5 volt output when ignition is on (5 volt reference for ecu ?)
3. One wire does show increase voltage on crank (must be reference wire for ecu)
4. one wire DOES NOT SHOW 12 volts when ignition is on. (my understanding is I need a 12 volt when ignition is on)

I cannot trace back the wire that should have 12 volts as I didn't do the wiring harness. I do not have the wiring pinout and hope tweakd performance can give it to me on monday. some other issues not sure if its related but the stock boost gauge in my dash is showing max boost when i turn the ignition on, I don't think its suppose to do that so I'm not sure if that is related to my issue of the car not running. I wanted to also check if I'm getting fuel but I reckon the coils are not sparking so I shouldn't get getting fuel either because they are all intertwined? I can hear my fuel pump prime if that matters.

one additional issue i have is the interior blower motor does not run, not sure if its related but when i turn on the fan i head the relay click over but blower fan does not turn on.

Any recommendations on what to do would be appreciated. what a dam headache this has been - end short rant

cheers!
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Re: Gen 4 swap not running. No spark at coils, help plz :)

Mon Jan 27, 2014 12:04 am

Check you injectors for power. Your coil and injectors share the same power source and should have power with the key on. Your coil from left to right should be


1 ground
2 ign trigger
3 signal return
4 12v power

If you do not have power there that's your problem.

Re: Gen 4 swap not running. No spark at coils, help plz :)

Mon Jan 27, 2014 4:35 am

Tecker184 wrote:Check you injectors for power. Your coil and injectors share the same power source and should have power with the key on. Your coil from left to right should be


1 ground
2 ign trigger
3 signal return
4 12v power

If you do not have power there that's your problem.


I know the issue lies within the connector not getting 12 volts as thats the only thing no showing up so do u have any ideas where i can check to see where the 12 volts should be coming from?

Re: Gen 4 swap not running. No spark at coils, help plz :)

Mon Jan 27, 2014 12:46 pm

Did you check your injectors for power? Your coils and injectors share the same power supply. One shouldn't have power and not the other. Power should be comming from the EFI relay.

Re: Gen 4 swap not running. No spark at coils, help plz :)

Mon Jan 27, 2014 9:26 pm

problem solved!!!! turned out that the ignition connector was loosely connected and one of the pins fell out. Repined and connector tightly fitted, fires up on first try!!! yay! thanks for all the advice all.

cheers
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