carlos8

hi guys, I'm having problems with my ls vtec Turbo, misfire at idle and turning the plug black (cyl. one). If I press the gas it rev almost fine but the idle drops to 500rpms.

Put new plugs start fine and after 20 seconds start to misfire 3 plugs are brown normal and this is completely black. If I disconnect the injector sometimes getting worse and others like the engine stabilized a little for a few seconds and get to misfire again. Comp. test fine 195psi, The wire measure 6.58 @20k ohm's (I'm leaning to the wire).

Swap.
coil
cap
rotor
plugs

NotARaCist

iTrader: (1)

Swap the wires for cyl 1 and 2. Does the misfire move with the wire?

carlos8

good call, ill do it tomorrow.

motoxxxman

black plug indicates rich condition. your injector is probably sticking. it's misfiring due to being pig rich and flooding that cylinder. unplugging the injector will make it run smooth again for a few seconds because it's still burning off the excess fuel that is pooled up in the mani/cylinder, then goes back to misfiring because it's too lean in that cyl.
most likely will need to replace the injector. or send all 4 injectors out to be cleaned/tested/rebuilt

wantboost

iTrader: (2)

also, check the injector on that cylinder. a black plug indicates a rich condition which could be causing the misfire. check to see if it has a proper spray pattern, doesn't stay open too long and doesn't leak. the easiest way to do this is unbolt the fuel rail, put a container under the injector outlets and have a friend crank the car over while you check it

also move the injector to another cylinder, drive the car and see if the plug on that cylinder comes out black. that will eliminate the injector as the cause. also check individual fuel trims in whatever EMS you use to make sure something didn't change in the tune

wantboost

iTrader: (2)

damn you beat me to it

carlos8

cool, I have my old set of Precision 650cc that I can use for test.

wantboost

iTrader: (2)

you need to test the injectors you are running.... not some other set

carlos8

Ok, so change the wires 1 to 2 and still misfire on # one.

So take the injectors out to get it checked, but the dam shop is closed due to a little earthquake last night 6.4 in Richter scale. I hope tomorrow all start normally again.

NotARaCist

iTrader: (1)

Since you can't have your injectors tested today, try swapping the 1 and 4 injectors, see if the misfire follows the injector.

carlos8

ok, ill swap them after lunch!!

wantboost

iTrader: (2)

also check the plug on the cylinder you swapped the injector into. if it's black like the other cylinder that would indicate an injector problem.

carlos8

Swap the injector the problem still in num. 1 Cylinder.

Put a new plug and comes dry black
Made again compression test 196-197
Put other injector on the plug, crank the car and pulse fine (tic,tic,tic).

Last shot, I swap my cams last week maybe I lash the valves incorrectly(tired and lots of beers).

carlos8

This is how it look after 2-3 minutes.

https://honda-tech.com/attachment.ph...1&d=1389645844

wantboost

iTrader: (2)

you've definitely got a problem somewhere. sounds like an electrical ignition issue, check the internals of the distributor

also recheck mechanical timing and valve lash if you have any doubts about it being done properly

turbohatch96y7

iTrader: (15)

cracked ringland?

Looks like oil not fuel.

Do a leak down test next

carlos8

turbohatch, I'm going to do the test tomorrow but one question.

It's possible to have a ringland cracked without smoking?

My only concern it's to pull the block to take it to the machine shop, I have a new set of Wiseco 9.8:1 82mm. The SRP's has given a good fight for 5 years so no complain and they are 9.0:1 81mm.

wantboost

iTrader: (2)

a cracked ringland doesn't smoke to begin with. the telltale sign is that the car sounds like a Subaru at idle, your compression test should show little to no compression on the damaged cylinder, if there is one

SRPs were always a budget, entry level forged piston. they have a different alloy and don't have some of the features of higher end pistons. this limits the kind of power/abuse they can take as the alloy just can't handle it and the piston will fatigue over time until it fails in some way

carlos8

thanks for the info wantboost, anyway I'm going to perform the leak test tomorrow, but it have 195-200 psi across the board.

carlos8

ok guys, just arrived from my cousin shop. Did the leak test.

Start the car till reach operational temp. fan come on twice.

1- compression test 197
2- leak down 4% @ TDC (feeling by the catch can breather).
3- not wet compression test made (tomorrow ill do it)

I believe those are good numbers for a engine with 5 years 12k-15k miles.

Now what should I look?

DDTECH

Was this car tuned?

If so where? .. how long ago and what was the numbers / setup when it was tuned properly , if it even was.

carlos8

Yes, sir

At dorado muffler Dyno P.R. (dynojet)
This set up was tuned in 2012
Engine build by me, tuned by my cousin.
393whp/287tq @18psi 93oct + 10% methanol

The engine was not touched since then, only maintenance and a few broken parts.

Ls vtec / b16 head p&p, 3 angle, ITR cams, supertech spring and retainers
darton sleeves 81mm SRP 9.0:1 eagle rods
king bearings/ NPR rings
sc34e / blox ported manifold
precision 880cc

NotARaCist

iTrader: (1)

When you replaced the cap, did you use a Honda OEM cap? It might be a long-shot, but pull it and inspect the #1 contact point for abnormal wear.

carlos8

Yes, rotor and cap are Honda OEM.

Tomorrow ill check that and going to measure the guts of the distributor for any abnormal reading.

DDTECH

That plug is basically, fouled.

Possible a spark issue, dizzy is tired, maybe going out?.. is this just on 1 cyl?

New plugs have obviously been tried, not the answer.

Has a fuel injector, from another cyl been swapped and its doing the same thing? If so, whens the last time the Valve lash was adjusted, and if it is adjusted, I'd look towards it being a injector or Spark issue.

Wantboost is right, but I've had personal experience with cracked ringlands, it'll smoke a bit on cold start up, but as the motor warms up, it'll get less and less, unless at WOT where pressure becomes too much and it will move the land.. this doesn't look like a ring issue, right now anyway, your comp test came out well.. decent but good.

pull all plugs...take a pic, report back