number #3 not firing , unplug maf and it dies....

[berman]

2 or 3 wires on going to the cam sensor? could possibly be crank sensor thats what is the misfires detector

[nekoabandoned]

what?

[berman]

lol sorry man i mean like how many wires are going to the cam sensor. there are couple types of cam sensors if i knew how many wires there were then i would what kind it is and would be able to tell you how to test it. usualy when a cam or crank sensor goes then you have more problems then just a misfire in 1 cylinder . alot of time a bad cam or crank sensor will cause starting issues. if you have narrowed it down to a cam sensor or ecu then my guess is ecu. you could always by a stand alone ecu system witch will help with preformance anyways and see if that fixes the problem if not then its not like you wasted your money.

[WhatsADSM]

This s*** is silly, you just keep randomly replacing stuff as opposed to actually diagnosing the problem. It is almost a guarantee it is the ECU you just don't want to believe it.

CAS controls the timing for the entire engine which includes all the injectors AND the ignition timing. If it were the CAS you would almost surely have bigger issues.

I told you days ago to try another ECU but you keep avoiding the obvious.

[nekoabandoned]

im not avoiding it , i just dont have a way for testing both and i dont have the cash for both....

[berman]

lol online drama gotta love it. i see were your coming from being a auto tech for a living you have to diagnose the problem before putting parts in the car or you mine as well use diagnoisic dice or pick the problem from a hat. there is no way for anyone who hasnt seen the car to properly diag the car so for you to say you know its the ecu is just stupid. not saying it isnt but i couldnt say for sure unless i personaly had worked on the car. may be you best bet before you waste any more money is to bring it to a good shop and have them diag it for you they will have better diag tools.

[vegita1647]

hey nick been trying to get ahold of you man vegita1647

[nekoabandoned]

erm who are you again, sorry i have a horrid memory.im spending all of tomorrow trying to track down the only other rb owner within 100 miles to borrow his ecu.... so we will know tomorrow hopefully

[WhatsADSM]

lol online drama gotta love it. i see were your coming from being a auto tech for a living you have to diagnose the problem before putting parts in the car or you mine as well use diagnoisic dice or pick the problem from a hat. there is no way for anyone who hasnt seen the car to properly diag the car so for you to say you know its the ecu is just stupid. not saying it isnt but i couldnt say for sure unless i personaly had worked on the car. may be you best bet before you waste any more money is to bring it to a good shop and have them diag it for you they will have better diag tools.

I'm not an auto tech but it sounds like I understand EFI a hell of a lot better than you do because we have essentially diagnosed the issue.

There is a FAR FAR FAR greater chance that it is the ECU than a CAS. As I have mentioned before, CAS controls ALL ECU timing operations. If it were the CAS there would almost surely be bigger problems, especially with the ignition side. He has looked for a mechanical issue such as a huge intake leak around that injector, or a clogged rail and said there was no issue.

Additionally we have had him check the wiring between the injector and ECU, and it was good. After that the guy proceeded to make another harness for some reason even though the wiring was already tested!? IN any case that FURTHER proves the wiring is not the issue. Timing is all there, injector is being powered however the coil is not energizing...

There is only one piece left in the puzzle that controls the injector opening:

THE INJECTOR DRIVER IN THE ECU.

As a side note, I also mentioned the original poster could go one step further to verify it was the ECU. He could repin (or just cut and swap wires, since he is willing to make new harnesses anyways) the ECU injector wires between injector #3 and another injector so verify that the problem follows that particular injector driver... But he chose not to do so.

[nekoabandoned]

ok well me (the poster) got ahold of a good ecu and cas today , after installing them no change. thanks for playing , any other guesses?

[WhatsADSM]

So you are telling us... just so I have this correct:

Mechanically here are things you have tried:- Bad injector. (You swapped injectors around but it followed the cylinder not the injector)- Compression check (was good so compression should be there)- Intake leak. (You pressure checked intake side and there were no leaks)- Fuel pressure is there (all other injectors work)- Clogged rail on that injector port. (nothing impeding flow there)

Electrically:- Wiring has good continuity b/t injector signal wire and ECU. Switched 12V is showing up on the other injector pin.- CAS is good all other injector/ignition works, and swapped with known working one. MAF is good, car otherwise runs.- ECU ground is good.- ECU good. (You changed ECU and still no fuel)

Now just to be clear you are SURE it is a fuel issue. Have you pulled the coil out and used a plug wire between the coil and the plug to make sure you have spark?

Honestly, if you have 12V on one side of the injector, and you are getting an injector pulse on the other, and you have fuel pressure going into it... Then that = fuel.

So if you are sure it is fuel go recheck for all those components, something is missing.

[Sil240]

Get a NODE light.

Go to Harbour Freight they have it for like $12.

If you hook a multimeter up to the wires you will not show a pulse, because it is so short and fast.

If it lights up, then you know you have a signal to your injector.

[nekoabandoned]

ok from what i understand the white/black wire on the #3 injector is the 12v constant and the white/red is the ground pulse. i went ahead and ran a new wire from the injectors white/red wire straight to the ecu, just to make sure it didnt have a break (even thou its a new harness...) then i ran a wire from the white/black to a egn 12v , well when i cranked the car i got a loud buzzing sound from under the dash where the 12v was wired in... i quickly turned it off...any ideas?next im gunna ground all the ecu wires stright to the frame and see if maybe theres a bad ground somewhere.

oh and to answer your question i took the coil completely out and just grounded the plug while it was in it. it has spark, unless that doesnt prove it o.o
Modified by nekoabandoned at 11:37 PM 7/7/2009

[nekoabandoned]

ok i went tester crazy and found out my o2 took a crap on me, would that cause a constant miss?

[berman]

I'm not an auto tech but it sounds like I understand EFI a hell of a lot better than you do because we have essentially diagnosed the issue.

There is a FAR FAR FAR greater chance that it is the ECU than a CAS. As I have mentioned before, CAS controls ALL ECU timing operations. If it were the CAS there would almost surely be bigger problems, especially with the ignition side. He has looked for a mechanical issue such as a huge intake leak around that injector, or a clogged rail and said there was no issue.

Additionally we have had him check the wiring between the injector and ECU, and it was good. After that the guy proceeded to make another harness for some reason even though the wiring was already tested!? IN any case that FURTHER proves the wiring is not the issue. Timing is all there, injector is being powered however the coil is not energizing...

There is only one piece left in the puzzle that controls the injector opening:

THE INJECTOR DRIVER IN THE ECU.

As a side note, I also mentioned the original poster could go one step further to verify it was the ECU. He could repin (or just cut and swap wires, since he is willing to make new harnesses anyways) the ECU injector wires between injector #3 and another injector so verify that the problem follows that particular injector driver... But he chose not to do so.

lol so like i said you didnt diag the problem if he had listened to you then he would have bought a new ecu for absolutly no reason. and im sure i know what im taking about i have probly used diag equpiment that you have never even seen or heard of before. but neways i dont what else to say about the car misfiring can't help you anymore with out looking at it good luck with it if you ever find the problem post it on here so we know what it was.

[HxC_Nismo]

ok i went tester crazy and found out my o2 took a crap on me, would that cause a constant miss?

no that would just cause it to run rich

[nekoabandoned]

ok so after running new wirings again to the injector, i connected the fuel pump straight to just the #3 injector , took out the cas and turned it by hand . the injectors firing! i have spark , i have compression , i have fuel. the gromet around the injector hole on the intake mani looks good but im starting to think thats it. im gunna pick one up tomorrow with a new set of spark plugs maybe that will finally fix this crap o.o

[WhatsADSM]

lol so like i said you didnt diag the problem if he had listened to you then he would have bought a new ecu for absolutly no reason. and im sure i know what im taking about i have probly used diag equpiment that you have never even seen or heard of before. but neways i dont what else to say about the car misfiring can't help you anymore with out looking at it good luck with it if you ever find the problem post it on here so we know what it was.

I'm sure you use equipment i have never heard of, and I have used stuff (hell made stuff) you have never heard of so what?! I am not trying to start a pissing match but was simply helping the OP diagnose the problem.

Also he didn't need to get a new ECU I also told him one way to test was to repin the ECU, and the very first thing I told him to do was the check the wiring... which it sounds like it was. Like I mentioned in my last post, something wasn't adding up he just had to go back and recheck everything.

ok so after running new wirings again to the injector, i connected the fuel pump straight to just the #3 injector , took out the cas and turned it by hand . the injectors firing! i have spark , i have compression , i have fuel. the gromet around the injector hole on the intake mani looks good but im starting to think thats it. im gunna pick one up tomorrow with a new set of spark plugs maybe that will finally fix this crap o.o

That's great to hear! BTW, just as HxC said, a bad O2 will make the engine run rich and can sometimes cause it to miss, however it won't be on just one cylinder.

Might as well replace the injector o-ring, and honestly while the rail is out you may also consider just doing all of them. Replacing/gapping the plugs can never hurt and it's cheap.... and finally if the o2 is truly bad it will probably cause you a lot of crusing/idle/closed loop issues until you get it fixed, so if you are sure it is bad then I would do that as well.

[nekoabandoned]

well after doing a compression test again...it came up with 145, 145,145,"115",150,145 so im guessing a blown head gasket, derrr the magic problem turned out to be a pain in the a**.

[nekoabandoned]

strange this is ... theres absolutely no smoke coming from the exhaust