spark issue

[wrs_guy]

hey i just put a new motor into my impreza but it appers to have spark issues what could this be i used the origanal plenum on the swap

[Stoffa]

What model impreza?

Do you have any spark? or just not working in certain cylinders?

forgot to bolt on one of the earth straps to the manifold.

igniter fail

HT lead fail

Coil fail

Cam/Crank sensor (I forget which one kills spark)

[wrs_guy]

its a 93 hx gf6 i just swaped motors from an ej18 to a ej20e using the ej18 plenum sensors and loom also did a manual conversion and have tripd the neutral switch anythin else you can think of ill go check its all earthed out?

[94 Leone]

You changed ecu too? I presume?

[wrs_guy]

nah i didnt change the ecu, cant i use the one that was in the car?

[94 Leone]

Err, it\'s not reccomended lol. It\'s likely that\'s causing your issues, as it\'ll be underfuelling, and have the wrong timing. Did you get the engine from another imprea? Or buy it seperate?

[94 Leone]

You\'ll also want to swap injectors and afm to match the ej20. Otherwise it\'ll throw cel\'s

[wrs_guy]

i scraped the other impreza, also the ecu\'s are different as the gf6 ecu is located under the steering wheel and is a 2plug and is half the size the gf8 impreza had the ecu in the passengers footwell, also the afm are different the ej20e use\'s the same afm that my 89 rs was running (green sticker ) gf6 ej18 has a alloy afm with the plastic modgul screwd in, its getting gas as i pulled a plug out and it was wet, its just not getting any spark at all tested this today?

[94 Leone]

Pretty sure drivers side is tcu(trans control) man. All ecu\'s are generally passengers footwell.

Though the ej18 ecu I pulled from the passengers side of a 90 something bg3 was a green plugged 2 plug ecu. But that was a legacy: not impreza. You\'ll probably have better luck just putting back in the ej18 OR you could put the ej18 heads on the ej20 block and make a hi compo engine though that then becomes troublesome because of the ecu controlled timing. as a general rule you don\'t feed a 2L what a 1.8 needs, as the 2L will starve.

[94 Leone]

What year are the two imprezas, one is a 93, the other a?

[wrs_guy]

the one ive takin the running gear from was 96

[wrs_guy]

how would the block and heads affect the spark? ???

[94 Leone]

Because you haven\'t changed the ecu, it\'s likely to not just be spark: if it worked before and it doesn\'t now: chances are it\'s a deeper issue: If you\'d done a re-loom and swapped over everything, ecu, dash, sensors, manifold etc. You\'d be better off, and it\'d be a less dodgy swap.

However assuming that the rest of everything is fine

Are You sure the leads are on in the right order?

Spark plugs gapped properly?

Leads on properly?

[94 Leone]

Also: because the 2L has different ignition timing to the 1.8 as different cc\'s it\'s likely that\'s affecting your spark.

[madmike]

94leone just chill for a bit a.....

Even if the car will be running a little lean it still should start..

He says in his posts that he has swapped from 1.8.-2.0 using longblock and has changed everything else over from the old motor...

Okay...

First up have you tested to make sure your getting any spark at all?

Are all your sensors plugged it correctly?

Go through the basics dude.

[wrs_guy]

ive tested no 1 cyl for spark had none at all, as for the sensor ive tryed the ej20 one and the ej18, i think ill take the plenum off and reconnect every think to ensure i havent missed any plugs or wire, secondly is there any wires on the second auto trans plug that i need to be connected together? and are the wires from the auto shifter alright just left unplugged?

[wrs_guy]

so after some comparing i relised my problem was that the crank part that the cambelt runs off and the crank sensor sits above (not sure what is called) were different so i swpped them over and reassembled the motor it now starts up first pop, now just gotta put the rear c.v.s in and take it for a run and see what it does but thanks all for your help!

[Subirex Automotive]

putting ej20 is fine, i did this swap in my mates 94 impreza. remember you have to use the crank and cam timing sprocket from your old ej18 engine into the ej20 motor. the timing gear pickups for sensors are different on both engines, this will send wrong signal to the ecu and there will be no spark.

you dont need to change the ecu.

also it will be wise to use ej20 injectors, or the engine will have rough idle.

[wrs_guy]

haha yeah i figured that wn i couldnt get spark i learnt the hard way haha