rb20 spark issue

[carcrzy920]

okay so i found out my ecu was bad from be being a dumb***. okay but i got my new ecu now and i got the car started. but it only runs on 2 cylinders. better than none like before the new ecu. i can start the car and itll idle on its own with 2 cylinders but it runs like poo. when its idleing i can unplug #2#4#5#6 from front to back and nothing happens runs exactly the same. checked voltage on the coil harnes and its barely getting .1-.2v on the signal wire. so im thinking my ignitor is crap. just wanted to get a little advice before i go dumping more money into crap i might not need. i was thinking about the j30 ignitor but i dont know which years would work. all the ones i see at the junkyard dont have hitachi or mitsu on them anywhere. thanks for any responders.

[SuicidnS13]

okay so i found out my ecu was bad from be being a dumb***. okay but i got my new ecu now and i got the car started. but it only runs on 2 cylinders. better than none like before the new ecu. i can start the car and itll idle on its own with 2 cylinders but it runs like poo. when its idleing i can unplug #2#4#5#6 from front to back and nothing happens runs exactly the same. checked voltage on the coil harnes and its barely getting .1-.2v on the signal wire. so im thinking my ignitor is crap. just wanted to get a little advice before i go dumping more money into crap i might not need. i was thinking about the j30 ignitor but i dont know which years would work. all the ones i see at the junkyard dont have hitachi or mitsu on them anywhere. thanks for any responders.

Are you sure you are only getting spark on 2 cylinders? Did you pull out the coil and plugs and turn the CAS to verify you are getting spark on all 6? Also while the plugs are out get a compression test. Even while cold atleast you can see if there is a variation in the compression numbers across the board.

[ST240]

Simple question, did you replace/look at the plugs? If you haven't, quit slacking and replace all six.

My rb20 ran like an absolute dog when i first fired it up; like yours only firing on a few cylinders. I replaced all the plugs with BCPR6ES-11 gapped to 0.8 mm (everyone runs this). Fired it up and she ran like a champ.

[carcrzy920]

all the plugs were changed before i put the motor in. ill replace them again since they probly got messed up from cranking it so much on the bad ecu. ill change those today and check my coils when i spin the cas. thanks.

also i totally forgot to mention yesterday i started it up and let it run for about 5 mins to see if you would get any code and i did. i got 12, 13, 21. 12 is mafs circuit, 13 temp sensor, and 21 ignition circuit. all of which seem like it could cause my car to act retarted as hell. its got the purple label mafs so that n60 correct? ill get 1 this sunday at the junkyard off a maxima. i replaced the single wire temp sensor with the ka one and i got it brand new. so which one should i get for the 2 wire temp sensor?
Modified by carcrzy920 at 7:52 AM 10/15/2009

[ST240]

i replaced the single wire temp sensor with the ka one and i got it brand new. so which one should i get for the 2 wire temp sensor?

The single wire one won't affect the engine's performance as its for the cluster signal only. The two wire one crosses with a 1993 300zx NA one. At least thats what i used and it worked fine.

[carcrzy920]

checked compression, plugs, and coils yesterday all came back good. ignitor thought is bad from what i can tell. guna replace the temp sensor today and see if the code goes away. ill post later today on the results.

[SuicidnS13]

Good update... how do you know the ignitor is bad? Spark to only a few cylinders, or weak spark?

[carcrzy920]

from timing cover back cyl #1 good spark, #2 weak but not that weak, #3 decent spark but not the best, #4 very weak almost none, #5 just about no spark at all cant even see the spark, #6 none at all. and i did the test with the same coil and plug so i would know the coil was good. mafs is going bad too im guessing because im getting the mafs circuit code, if i unplug it the engine dies so it does have a little life in it but i did drop it when i was putting it in so ill pick one up at teh junkyard tomorrow since i have a n60 on it now. didnt get around to the coolant sensor yet but thatll be taken care of today or tomorrow. i have someone coming over in a little bit with his rb20 s13 so we can swap ignitors just to be 100%. ill update when i start replaceing parts.

[carcrzy920]

okay new update. I HATE MY CAR!!! okay so i replaced the ignitor with the j30. and wouldnt you know it, its still a 2 cylinder. still have all the same codes i had before. i changed my mafs too. it had a purple label n60 on it so i got one at the junkyard and put it on and i still get code 12 mafs circuit. can someone please help me out. This thing is really driving me crazy. heres a check list.

1. plugs are a little dirty but not enough to cause this2. coils all fired when i put them on one of the cylinders that fires3. ecu changed4. ignitor changed5. no shorts in the wires between ecu and ignitor

what the hell else is there to check. could the CAS cause something like this? are there any the Xreference with the rb20? ca18 or z32?you can text me too with in info at 540-903-4022

[carcrzy920]

okay soooo i found a pretty big vac leak today at the tb. like really big that its pretty much leaking all around it. guna fix it tomorrow and check all my couplers to see if i have any others. but would a vacuum leak cause it to act this stupid? i get spark on all cyclinders now and good compression and fuel (i think). its got about 38psi on my inline fuel gauge and all the injectors click. i pulled them all out today and they all seem clean and i whiped them off and sprayed them with a little tb cleaner. no change so im guessing this is just a really big vacuum leak i hope.