[scottdh20]

ok I have had a very long drawn out thread over here:

http://www.d-series.org/forums/general-tech/210730-car-died-after-auto-x-help-me-diagnose-5.html

it has fixed several problems but none fixed the real problem at hand. so here is a thread dedicated to that.

build specs are lengthy but your generic d16y7 vitara/eagle. head is fully built with a ton of machine work, crower springs, sk2 valves, delta 272-2, aem gear, etc, etc..

that being said I have already done a shit ton of diagnostics and things to track this down, I will try to list what I have done to better help you, help me.

the long story short is the car is cutting out at what can only be described as a loud popping sound, like a fire cracker. was at 5k but is now closer to 6k since I removed the boost controller. it pulls hard, feels great and then a brick wall and popping, like antilag...

so what I have done:

-fresh bkr7e plugs gapped at .22
-swapped out my borg warner spark plug wires to ngk blues
-replaced coil in dizzy with spare
-replaced ignitor in dizzy with spare
-replaced whole dizzy
-replaced engine wire harness
-new battery -was bad
-new alternator -was bad
-lowered boost from 20psi(with b.c) to 14psi(wastegate)
-check every fuse for parasitic draw-good
-check timing, double and triple checked it and used a timing light, its dead nuts
-compression is good
- I was self tuning with ectune, I was thinking I may have pulled to much timing causeing the issue. my laptop is dead and currently being repaired, so I went old school. downloaded crome and flash n burn on my wifes laptop and dug out my good ole burn1 chip burner. fuel at 180% and timing at .75 per psi retard. added all the tools,not going to go into detail but those who know, will know whats involved in a crome map, took some time relearning the long lost crome...lol...set my injector offset to 40 was a bit to lean 15s then to 45 and high 13 low 14 so im still need to change it to about 42-43 and it should be golden....when doing a pull it tips in at upper 12s and drops to high 11s at 12-14 psi. pulls like a freight train till I hit that ungodly limiter.

so being that the issue has persisted through two different tuning programs im going out on a limb and saying its not tuning related

back to mechanical....

wondering if it could be valve float? I don't know what it feels like but with a bit of research seems like it could be causing a problem like that. but the crower springs shouldn't be floating, unless the cam is all whacky. to be honest I don't think I have ever had this cam over those rpms.

next on my list to diagnose is the delta 272-2. I have a full stock d16z6 sitting in my garage I may snatch the cam out of and just test it.

other than that I have zero ideas of where to look after that. wanted to hit up a autoX this weekend but unsure if its gonna happen unless this issue gets resolved quickly

 

[scottdh20]

in the middle of the cam swap

delta 272-2 looks good...no scarring

lma's all look good as do the LMA pads

so good news there since apparently the 272-2 is a LMA killer

took a break for dinner, gotta do the valve lash.

pics for the whores

272-2

randomness ...what's up with the two different lma's ...both out of z6's, the triangular ones are out of my car and the cylintrical ones are from the Donner

 

[FarmerD]

Post up some pics of the rocker pads.

 

[scottdh20]

sorry Dan it was already put back together. they looked pretty good, i compared them to the st;ck z6 i had sitting there. had some freinds come over which made valve lash go waaaay easier.

long story short was I was ripping all over the place. way more low end power. part throttle is like heaven, drives like a stock civic just cruising around. I couldn't shift hard from 1-2 it was spinning like crazy. tons more power. pulls way fuckin harder. wasn't cutting out I was trying to shift at 7-7500 being a stock cam....its pulling harder now at 12-14psi than it did at 20 on the 272-2....

I will hold out just a bit on judgement I'm going to an autoX on Sunday at the same location it died last year...so it will be a great comparison. if all goes smoothly I think I found what has been plauging my build for 2-3years now...never thought the cam could be the issue...now I can't wait to get my tuning laptop back so I can get this back on ectune so I can crank up the boost. not to comfortable on crome free pushing much over where I am now

 

[Darin T]

have you data logged when it has happened?

 

[scottdh20]

nope, data logging has never worked on my laptop...even talked to Dan on the phone for like an hour trying to get it working and for some damn reason won't work.

doing hours of searching for what can cause a backfire/ popping/ banging noise in the upper rpms I kept coming across valve float. being I have Crower springs I dismissed it. after the test with tuning program failed I was racking my brain. there are only so many moving parts or thing that could cause it...fuel good, spark good, electrical good, tune good, it only left something mechanical. well crower spring shouldnt float but i have a regrind cam....what if there was an issue or mistake made while grinding, i dont know a ton on cams but what if it had to much lift or to much duration? the cam directly controls the valves and maybe the vtec lobe is simply too agressive? again I'm not convinced I'm cured but I will be beating on it a bit more to find out as well as hitting up the autoX

 

[TurboD206]

Soo It sounds like you had some serious valve float going on with the 272-2/Crower springs combo.

The stock cam makes more torque and drives better for a DD.. damn

Delta Camshaft is right down the street from me and I was going to have them do a grind on my spare y7 camshaft when I have some extra dough..

Im not sure what do now though .. Bisi's not getting shit from me lol.. so whats left? hmm

Im glad to hear your car is back in action again after the headache it was causing.

GL in autocross Let us know how it turns out.

 

[Darin T]

That really sucks, I'm sure you could get some good data if it worked.

 

[FarmerD]

That really sucks, I'm sure you could get some good data if it worked.

x20923901823.

Thats how we fixed almost every single problem we ever had with our cars at the track. Get that shit resolved Scott!

 

[scottdh20]

took a short trip to mexico, saw a 300z driving all fast like...chased him down, lined them up...I didn't launch, kinda luged it off the line, launching wouldn't have helped being on old ass proxie4's anyway ....he got me out the hole obviously. he pulled is rear wheels to my front, 1st started spinning , short shift to second he pulls about 1/2 car in front and to about 100mph that's where were stayed....so it can hold its own...pull up to the light and we roll down the window and chat, he makes 380whp

so its making some power to keep up with a 380whp 300z

 

[TheToaster]

Check for a Chaffed Wire



I got much better performance going from 272-2 to stock Y8 cam.

272-2 is garbage.

I don't think this will make the car cut out though, unless the tune is broken?

Can you read Lambda, and hear your timing?

 

[shoebox_civic]

I'm sure you guys went over it trying to get datalogging figured out, but are you 100% absolutely sure J12 is cut completely?

mine had a tiny sliver of solder bridging the vias and that was enough to fuck up datalogging for me until I checked it with a meter

 

[scottdh20]

same tune on the 272-2 and on the z6

the z6 works as it should the 272-2 doesn't. nothing changed except the cam and re lashing the valves which were double checked before cam removal and they were good. the car revs out and all drivability issues are fixed.

I went on youtube and watched some floating valves videos as well as reading up on symptoms and it was almost to the tee the symptoms I had. but the crower springs weren't floating.

either way the cam fixed whatever issue I had, chalk it up to a bad grind or whatever...either way its fixed

I have put a couple hundred very hard miles on the car...has yet to skip a beat

 

[TheToaster]

Can you look for edges on your 272-2?

Like in my Review thread?

 

[scottdh20]

look at my second post it has a pic of the 272-2

 

[TheToaster]

Can you do better?

Clean and dry , light angled properly?

 

[FarmerD]

Crazy if it was the cam. Jeez... glad I sold mine.