Evilparadize

What causes this? Lean or rich mixtures? Car feels slughish, feather the pedal and car runs great and picks up speed fine, smash on it and car stumbles and feels slughish! BOGS! WTF? Happened a year ago hitting 8K plus RPM's on L.A. freeway, 2000 Civic Si stock B16, input is highly appreciated! Clogged injectors, fuel filter or fuel rail?

93egSLEEPER

sounds like timing is off. it isnt getting anough fuel under full throttle. might need a good tune also.

Evilparadize

Timing right on the dot,nothing, advanced, nothing, retard,nothing seems to improve the response or performance. Car used to feel nice and strong, now feels slughisgh and rough. Car also has an intermiten missfire, which leads me to either fuel or vacum.


Modified by Evilparadize at 10:39 PM 2/10/2008

slowcivic2k

Carbon deposits are a product of combustion, so they will always be there, whether they are excessive or not is the question you should be asking.

Poor fuel (and when I say poor I don't mean LOW OCTANE!!!! ) can cause excessive buildup. Most fuel detergents are universal, but some places go the extra mile and add their own.

Using over-the-counter additives in your fuel can also cause carbon buildup. Not only that, they can foul out spark plugs and damage your O2 sensor or catalyst.

Intermittent misfire can be caused by a lot of things. Consider age, the injector pintle could be partially blocked or stuck, worn out plugs, poor ignition wires, poor compression, clogged fuel filter; the list can go on forever. If the car is falling on its face when you give it fuel, it could also be an air metering problem.

Before you pull out the "diagnostic shotgun" and start replacing things that don't need to be, give us a history, what was done prior to this problem, and so forth.

King V

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Evilparadize &raquo;</TD></TR><TR><TD CLASS="quote"> Car also has an intermitent misfire, which leads me to either fuel or vacuum.


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That would lead me to say change your plugs and wires first. I've had an issue with my car where if I put on anything but Honda wires and good plugs it would run like total **** all of a sudden.

Evilparadize

Excessive carbon deposits is my problem, I figured people would magically know what I meant, my apologies.

91 Octane is all I use, whether it's Mobil, 76 or Chevron. It's hard to choose just one brand as everyone claims theirs is the best, however I did notice the car perform a little better after using Chevron. I also heard that Chevron does use other additives or detergents to help prevent build-up.

I have never used any over-the-counter additives on the car for the same reason, I've heard that they can cause more harm than good.

Before the problem occurred, about a year ago, the car performed like a beast. At the time the car was mostly stock with just a short ram intake and 2.5" piping from the cat back with a straight-flow exhaust. The issue occurred while on the freeway going at about 80-90mph, engine made a weird noise, the check engine light came on and I immediately noticed a decrease in performance (loss of power), I pulled off the freeway and into a Mobil station. Oil level was low so 2qt of Mobil1 were added and I reseted the ecu to clear the CEL, now this is where I F'ed up because I should of pulled the code.
Next day I did an oil and filter change, new plugs cap and rotor and cleaned out the intake filter. I also checked the TPS, injectors, coil and water temp sensor for proper voltage, but no change in status. Few months later I pulled the head and noticed excessive carbon build-up on the pistons and valves, so I got the head hot-tanked, ported and polished with a 5-angle valve job, new exhaust valves, seals, dual springs and titanium retainers. Installed the head with new Honda head, intake and exhaust gaskets, fuel filter, Accel plug wires and iridium NGK plugs, Walbro 255 fuel pump, both O2 sensors and a new distributor from Distributor King, adjusted my valve lash and finally I replaced the ECU with a known good working unit. After all this, still no change in performance, ever since that day, the car has never felt the same. I replaced the cat with a test pipe to see if the cat was shot, but it actually didn't look bad. I want to get my injectors cleaned and balanced by RC Engineering but at the moment, I feel like the car might be ruining too lean since the plugs indicate that. Compression tested slightly high at 210-220 on all four but I think it's due to the excessive carbon build-up.

King V

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Evilparadize &raquo;</TD></TR><TR><TD CLASS="quote"> I feel like the car might be ruining too lean since the plugs indicate that. .</TD></TR></TABLE>

Carbon deposits are a sign of running rich. If you were 2 qts low of oil running 90 mph on the freeway and did all that top end work on the car with no change in the cars attitude, I think you may have either a tuning/wiring/sensor issue or you f'ed up the lower end of the engine. I would try to find out why you're getting too much fuel in the engine.

slowcivic2k

Pictures of the plugs will help. A whitish tan ash on the ground strap is ideal. If the insulator is discoloring or burned, that is usually a good indicator of a lean condition. Some fuel additives can also damage/discolor the plugs.

2 quarts low is dangerously low, do you have an oil leak or burning issue as well? I would suggest checking your engines oil pressure. Oh, BTW, what weight engine oil are you using? I don't wanna hear anything but 5W-30.... Oil pressure puts a considerable drag on an engines output, using oil that is too thick can destroy the pump, ruin bearings and rob you of power.

If you've tested the sensors, please tell us what the results are. In particular, the Coolant sensor, the TPS and MAP sensors; these are the most important.

210 is fairly good for a healthy B16. But more important, did they all build pressure equally? I'm not about final pressure, but the first compression stroke and the next are the most important. If you got one hole that builds only 60psi on the first compression, and the next hole only gets 40psi, but the final pressures are 210psi, that is a bit of a concern.

Is there any reason why you are using a walbro 255? If your car is in fact running lean you may have ruined your fuel regulators diaphram.

jdmisoverrated

i should snap a pic of teh f22b2 head
youd **** your pants.
dont think oil has ever been changed.
the head is cracked and clogged up like a
yeast infected pu$$y but bottom end is good
ill snap some pix as soon as i get the stubborn head off.

JDM_EK_wanabe

try checking your map sensor, mine kinda ran like that a while ago, turns out my plugs got a little coroded and wasnt giving the right voltage, it ran like total crap and it didnt even through a code untill like a month later when it was so bad that it just didnt want to start

blk92_d16

My guess is a broken ring/ringland which is passing more oil/build-up tp form. Plus, during a compression test if there's oil in the chamber it'll create better #s. But then again, I don't remember you saying the plugs were oil-fouled or anything... Since you re-did the entire head, I think it's time for the bottom-end.

Evilparadize

How do I post pictures? When I pulled the plugs out, the insulator seemed slightly burned.

The car has no oil leaks but does burn a lot of oil. I'll definitely be checking the oil pressure once I get an oil pressure gage. Nothing but 5W-30 Mobil-1 Fully Synthetic.

I don't remember anymore, but at the time, I compared the results with a Haynes manual.

All 4 cylinders build pressure equally and gradually, with high first stroke numbers, but I have never performed a leak down test, which can determine a lot.

I replaced the fuel pump just in case the stock one was bad, but I never checked the fuel pressure .Not very good troubleshooting skills, but the problem occurred before anything was done to the car. Anything that has been serviced or replaced in the car (other than regular maintenance) is because of the initial problem.

I did, when the issue occurred. Again, I don't remember the results but they were compared to the manual at the time.

You may be right, but the plugs have no oil. The mind bog is that I don't know if it's something physically or mechanically wrong with the engine (block or head) or if it's a damn sensor. No CEL's what so ever after I reseted the ECU the day the problem occurred.

Evilparadize

Well, the car started to missfire again, bad, and the first thing I did was unplug the plug wires from each cylinder one by one. Turns out, that number 1 was the culprit. So I checked for spark and it was fine, nice and strong. I moved the injector harness around and the missfire went away, which leads me to believe it's either a bad connection to the injector, or the injector is f'ed up. Could also be the seal between the injector and the intake manifold, which may be causing a vacuum leak and causing the car to lean out or the seal between the injector and the fuel rail. I'm concerned about this because the first time I pulled the injectors out of the manifold, I found some dirt and grime from the seal all the way to the spray nose inside the intake port on all four. None the less, car still feels sluggish.

slowcivic2k

If you suspect the injectors, perform a resistance test on the solenoid. Also check for resistance in the power side on the injector harness (power wires are all the same color), and check the resistance of the grounding circuit by unplugging the ECU, and check that injectors pin number to its ground on the injector clip.

Some buildup is normal, I believe it would not be the cause of the problems your having.