Olivia - 69 2 door 510 sedan - fully built CA18DET

[aintnobiscuit]

It's off. The head gasket looks perfectly fine. I think my i just needed to go back and re-torque the bolts after a while of sitting.

 

[Eagle_Adam]

damn! ive made half that much progerss on my dads motor today

[aintnobiscuit]

Well, my girlfriend wants me to do all this stuff this weekend (getting up at 5:30/5:45 tomorrow) so I most likely won't have any other time... therefore it's do it now or don't do it in time to tune....

 

When those are you're choices, it's not hard to keep going.

[aintnobiscuit]

Hey guys check it out! Almost done! I'm going to bed.... my girlfriend said i can finish tomorrow night :D

 

[SR20DETdatsun510]

You got it handled bro! VIDEO!

[DAT510]

FUCK.

You're insane dedicated bro! Keep it up!

[Eagle_Adam]

Fuck.....

 

That is all

[aintnobiscuit]

sorry, moms birthday yesterday and 3rd thanksgiving (step mom's family) was today so I didn't get to start until 7:30. Anyway, I don't know if I posted the other compression #s.

 

With MLS freshly installed

150psi across all 4

 

After I blew the MSL (looked fine... not sure why oil was blowing through the layers...????)

140psi across all 4

 

I just did a compression test with the OEM gasket installed and it's at 140psi across all 4.... but I'm not sure my gauge is super accurate. I noticed if I hold it at an angle, it loses pressure. It's brand new too... I bought it just for this build because my old one was missing the fitting for the size of spark plug I have.

 

I know 140 doesn't mean the HG isn't right, but it could mean i blew my rings or they are not sealing.... anybody have equipment to do a leak down test? I need to find out / fix it before saturday if I want to do the tune....

 

I'm going to throw the coil packs on and see if it fires up / take a start up video.

[aintnobiscuit]

No dice... it started up and immediately died. I took a look at the plugs and some were wet with fuel. I took the coil pack cover off and more than one have frayed wires that are arcing. It's still getting a spark on all cylinders, but it's weak. Anyway, going to go through my spare parts bin and try to find another coil harness. Im not doing any more tonight, but I will when i get home tomorrow...

 

sigh....

 

Pretty close though...

 

I shot a fireball out of the exhaust though, that was rather cool.

 

:(

[aintnobiscuit]

OK, so here's a video of whats going on. It actually does not start at all now. The compression is the same across all 4 cylinders 140psi. I think it is related to the spark issue above. I only let it run that long to see what the AFRs were looking like and what cell it was in. It sounds like it's only running on a couple cylinders right?

 

If you have any thoughts, I'm open.

 

Only thing I'll be doing tonight is swapping the oil out with clean oil, looking for a coil harness and some diagnostic shit to try and find the issue.

 

http://www.youtube.com/watch?v=ypfgiq0Y1UM

[erichwaslike]

... fuck..... its definitly only running on 2-3.

[aintnobiscuit]

Yeah. I'm a little bummed. It started doing this with the MLS head gasket on, and when i saw the oil and the slightly lower compression #s, I assumed it was completely blown. Now that I'm looking at the numbers and seeing the same #s with the stock gasket, I'm not sure what to think.

 

There's no smoke/burning oil from the tail pipe at all. The oil looks pretty clean for going through a break-in. Theres no coolant in the oil and vice versa. Literally the only thing i'm seeing is it's running on a couple cylinders and compression is slightly lower but still within spec.

 

[Eagle_Adam]

keep at it man! you got this

[aintnobiscuit]

I'm just going to say that it's the coil pack harness. If I can't find one i'll just wrap the wires in electrical tape or heat shrink them.

 

Should help me identify WTF is going on.

[Eagle_Adam]

i dont envy you, wiring is the only reason i haven't attempted a swap yet.......

[aintnobiscuit]

ha ha ha, the wiring actually wasn't bad.

 

You know, someone mentioned cam timing in another thread (nicoclub) and although i'm pretty damn sure the cam timing is right, I'm going to make sure the belt didn't slip a tooth during startup or something along those lines. I had ruled that out, but it is a possibility.

[Eagle_Adam]

i fucked up the cam timing on an L motor last night cus i was too tired to be wrenching, granted i only have to untorqe the head and try again so it wasnt all bad but my point is even the simple shit can get fucked up

[fo0manchu]

dang man, sorry to hear all the trouble. Have you timed it with a gun yet? Also, some of the old harnesses get corosion at the connectors. For my buddys z we had to sand the corrosion off the connectors for about 4 of the 6 fuel injector plugs and BAM! it fired right up. Took us awhile to figure it out though. Are all the injectors working properly? Make sure they are not stuck open and flooding a cylinder.

 

Does sound like cylinders are missing. Spark and/or fuel. those are the 2 things i would check. But i think you already know this. Good luck!

[aintnobiscuit]

Yep, spark to all cylinders, just looks weak. I have a spark tester (you put it inline with the coil pack on top of the spark plug). For fuel, i pulled the fuel rail out with injectors attached and then turned the cam angle sensor by hand. All 4 sprayed fuel.

 

As far as timing, yes, i locked the haltech at 10* and then set the timing on the cam angle sensor so it matched up with a timing gun. I didn't use the loop on the back of the coils, as this gives a false reading. I timed it off the #1 coil using the spark tester as a spark plug wire per the FSM.

 

:)

 

Stole this image. Where the wires connect to the plug, the covering on the wires are melted and it's arcing between the two wires. This is happening on at least 1 coil and it arcs with every single fire, not just that cylinder.

 

[aintnobiscuit]

Son of a bitch.. i never even thought of this.....

 

You can install the cam angle sensor 180* wrong very easily. If you're not at TDC when you install, it will be firing on the wrong stroke. That would make sense with the fireball.

 

Yes! Two things to test!

[aintnobiscuit]

Aww man, what i said about the cam angle sensor doesn't make sense... i'm reaching.

 

I repaired the wire on the coil and am going to check the cam timing right now.

 

I have another coil harness and cam angle sensor which i can try as well, but the more i think about it, the less sense that makes. If my cam angle sensor was bad, i wouldn't get spark or fuel.

 

EDIT: Lined up the timing backing plate with the holes (instead of holding it all the way up) and my exhaust cam is off 1 tooth. That could be a contributor. Fixing now

 

Intake cam

 

Exhaust cam

 

Crank pulley

[Josh K.]

its almost always multiple things. Just try not to convince yourself the symptoms point to one thing.

 

I remember one time on my sr20 everything pointed to a bad Maf. It just didn't quite add up though. Doug at up garage told me when he's troubleshooting he starts with the obvious. Are the tires good? Check. By the time you find the problem you find 5 things that contributed to the symptoms.

 

My problem was the bearings in the camshaft angle sensor were going out and getting hot and seizing at 2500rpm causing it to miss.......

 

:sneaky:

[aintnobiscuit]

Oh man, thats crazy shit! I'm done re-timing the cams to make sure so next i'm going to test then try a different CAS.

 

I definitely agree with you. If you follow a logical line of things that can go wrong, you can rule things out that helps you figure out the root issue.

 

I think maybe there is no spark to all cylinders. The reason i think this is because it will read insanely rich sometimes and others normal. If the coil harness is bad or it's not getting spark, a lot of unburnt fuel enters the exhaust. It doesn't take much to have the 02 sensor read really high.

[hobojobo]

Even though the misfiring sounds like shit, I can tell that it will sound good whenever you find the problem. may the force be with you

[aintnobiscuit]

HAHAHA, thanks man. The car sounds pretty beastly when it runs. I was so excited when it was running well enough for me to actually drive it around. I was driving up a hill (i live at the top) so the turbo spool was very loud even though it was only at like 7/8 psi. The kids on the sidewalk just stopped and stared. Then that glorious blow off valve... man... i wanna drive!

 

Here's the latest:

 

 

Reinstalled everything and tried to fire it up. Same symptoms but I noticed additional arcing from the coil wiring. I repaired the coil wiring and found even MORE arcing. FUCK.

 

I looked through all my spare parts and found another coil pack harness. It's now reliably running on 3 cylinders. It will stay running if I give it some gas but dies at idle. I swapped out the current CAS another CAS and have the same issue.

 

So that means (IMHO) it's most likely not timing related and that rules out the CAS unless I have two that are bad... but even then, if the CAS was bad there would be no spark or fuel. So it's still ruled out as being bad. I think it's something related to spark or a fucked injector connector. I can't keep trying to start it up because its after 10pm and i'm sure my neighbors are annoyed. Our garages are attached and they never go in there. They were banging around in there doing stuff after I had tried to fire it up a few times.

 

Well.... I'll just have to speculate all day tomorrow until I get home.... But that has helped me figure things out in the past, so it's not all bad. Going to make a list of possible problems and address them one by one when i get home. If anyone has some ideas, feel free to throw them out. Even if you think they're dumb, I'm open. Even if it's not bad, it could lead to me thinking of something that is an issue so all thoughts are welcome.