1j is in but idle is rough

[cruzinbill]

so finally got the swap done in my SC but idles is quite awful. i was gonna throw a timing light on it but i have the type that connects to a plug wire... so how the hell do i check timing on it lol. also is there any thing like a CPS i can adjust or do i just make sure the crank and cams are lined up. thanks

 

[Freshmaker]

You can't adjust timing like a distributer as far as I know. TPS can be adjusted, but only do it if your sure it needs adjusting. It is quite sensitive.

Do you have any engine codes? Checked your ECU caps? One other thing to check is make sure you mounted that thing that removes "noise" from the igniter circuit to a good ground. I have never dealt with a problem but heard it can cause some mis fires.

My 1jz had quite a bit of "pops" to it when I first started it up. After driving for about 30 seconds the idle cleared right up though.

 

[cruzinbill]

hmm where is this noise filter? after looking at a few things i noticed that i can unplug all the coilpack plugs and nothing changes. except cylinder 1 and 3 i think its running on 2 cylinders... so the filter thing somewhat makes sense

 

[Freshmaker]

It has 2 wires going to a small black box. Its mounted on a small metal bracket. It should be around your igniter somewhere.

That doesnt really sound like your problem though. What was involved in your harness modification? Here is a diagram of the 1JZ. Checking the wires between the ignitor and the ECU is easy enough I would start there. Checking the ECU caps is easy too.

http://jzgte.com/tech/1jzgte/1JZ-GTE.Wiring.v1.1.pdf

 

[cruzinbill]

well since i did mine with a soarer eng in a sc not a supra all i had t do was extend the body plugs everything else plugs in

 

[Freshmaker]

Have you checked your ECU yet?

If that is good, I would start with normal cylinder mis-fire diagnosis. Locate the missing cylinders. Check for spark, check the injectors and circuits.

 

[Jaguar]

Check the ECU

 

[cruzinbill]

checked ecu, its all good no messed up caps or anything. then I went to trouble shooting. all coils ohmed 1.2 and all are getting power. Timing is lined up. need a way to check the injectors tho. also take a look at this what do you guys make of it

 

[rakkasan]

I'd say ignitor since only three are smoked...

 

[cruzinbill]

any way to check the ignitor like with a volt meter or anything.

 

[josh930]

123 looks rich as hell and 456 look as if there is no ignition.

 

[cruzinbill]

yah lol thats why i was like wtf is going on. ive never seen it with the front half and back half like that tho. im not worried bout the richness honestly im worried about the back half.

 

[cruzinbill]

ok little more narrowing down and im def not getting any fuel to the rear 3. does anyone know what would cause just the rear injectors to not put out fuel.

 

[rakkasan]

ECU.....

 

[cruzinbill]

ok... ill try to find someone selling another one then.

 

[Freshmaker]

Sorry, I was gone for the week-end. You made some good progress I see.

3 firing and 3 not firing, that seems pretty strange. To be more specific: Our injectors are batch fire. The ECU sends a signal that is supposed to fire 2 injectors at once. If the ECU was bad you would have problems with cylinder 1 and 4 for example.

Your problem seems to be after the ECU. So, check the wiring to each injector, and check the injectors themselves.

 

[cruzinbill]

ok each injector is getting 12v to both sides with the key in the on pos

 

[Freshmaker]

Ok, lets check the signal wiring now. Since we know 3 injectors are getting signal, we can use them as a reference.

Your going to pull off one of the plugs to a missing cylinder, then the plug to the corresponding working cylinder.
Make sure your ignition is off to be safe.
Then, check continuity between the pins of the plugs. You should have pretty much no resistance.
The corresponding plugs are as follows:
1 & 4 W-L wire
3 & 5 W-R wire
2 & 6 W wire

Also check the resistance of each injector while its not plugged in.

This shows the wiring if your interested.
http://jzgte.com/tech/1jzgte/1JZ-GTE.Wiring.v1.1.pdf

 

[cruzinbill]

ok i think its fixed. one of the pins was not in all the way in my ecu plug. all seems to be well now. it still has a tiny bit of roughness due to idling really low but it revs very nice and clean. so i may adjsut the idle up a bit

 

[91 mK3]

maybe you might want to check and see if your tps is at where its supposed to be. that should help your idle. make sure your coilpacks are connected and nohing is broken. also, drive it around a little if you have fuel to all of your injectors. sometimes it hels.