My hesitation issue...

[Acecool]

Ok, turns out my 3rd cylinder coil isnt firing properly when hot... the coil is getting power, but when I unplug any other coil, the hesitation is 10x worse... if I unplug the 3rd one, then the hesitation is still there, no change....

Anyone have a spare rb20 coil?

Josh

[StricNyne]

how close r u to georgia ? isnt jhot and a few other shops down there ? im sure you could get one from them for under 50 bux

[Acecool]

I am in SC... on the coast!!!!

in charleston... about 1:30 to 4:00 from Charlotte...

[AxiOn419]

I dont think Jhot has any at the moment. Their rb20 parts motor is stripped down to nothing but a block now. I am right up the street from them

eBay is always your friend, http://cgi.ebay.com/ebaymotors...ZWD1V, though that seems a bit expensive for just 1 coil pack.

Are you SURE it is the coil pack? I would swap coil packs from one of the cylinders you know is working and see if it acts up still That way you can be certain before you buy parts.

[Acecool]

Well.. Coil packs brake down when hot... Runs great when cold, acts up when hot!

ill swap number 2 and number 3 once the engine cools down a bit, maybe take a spring from a pen too lol....

Josh

[AxiOn419]

I remember in an earlier post you made you said one of the packs was missing the carbide tip (or whatever kind of tip it is) that was attached to the spring, is it that coil pack acting up? Even though that still should not be the case, may be something to check. You can also use coilpacks from a Q45 (the front 2), so if you cant find any rb20 packs, search for q45 packs, may be easier to find.

Also, as a definitive test. Pull the pack that you think is bad, unhook all of your other coil pack wires. Put a spark plug inside the boot of the one you just pulled, touch the tip of the spark plug to your valve cover and have someone crank the car. See if you get spark.

[Acecool]

Yeah, that one has just the spring, and that was the best looking pack of all (completely silver inside instead of bronze)

Ill try swapping 2 out, and changing the spring with one from a pen... lol... and seeing if that helps..

Josh

[Acecool]

Swapped coil packs... same issue same cylinder...

if I unplug any of the other coils, idle gets worse... cylinder 3 = same....

sparkplug is black - new ngkCondition 3: Black sooty deposits indicate an over-rich fuel/air mixture or a malfunctioning ignitionsystem or incorrect (colder than appropriate) heat rating plug (N.B this is most likely what your plug willlook like with faulty coils, but not always)

So, coil is ruled out because cylinder 1 worked, and I swapped 3 with 1.. same issue same cylinder...

Spark plug - maybe, but should still work.....

Igniter maybe?

[AxiOn419]

Good thing you ran that little test

Ignitor is possible, especially once it gets heated up. Those things can get hot. I have a spare rb20 ignitor if you happen to need it.

Check for continuity so we can rule out the wiring. Check from the #3 coil pack to the ignitor, and from the ignitor to the ECU. Check for it after it is warm. Chances are it is fine since you said it was firing when it was cold. Check for loose connection, make sure you fuel injector is tightly plugged in as well as the wire for it.

Also, make sure where the washer from the spark plug seats is not full of crud. I had an issue like yours, cant say for certain that cleaning it is what fixed it but it was one of the things I did.

Of course checking spark plugs will be easy, you can swap them over just like the coil packs.

Did you try the spark plug to valve cover test? That will tell you if you are alteast getting spark or not.

[Acecool]

OMG.... I may need to change my pants!!!!

I took the coil back out, and the spark plug as I said in the above post...

Put it back in... took the spring out of the coil and said **** it.. I stretched the spring out a bit to make it about 2x as long as it was... put it back together (same thing on cylinder 1) and omg...... I gave some gas and I was GONE!!!!!!!!

Wow!....

Im going to be driving it tonight for about 4 hours (did last night too, and she ran great except the sputtering) but it might be solved now, so awesome!!!!!!!!

Josh

I need replacement springs.. lol

[Acecool]

Well, I drove it tonight for about 4 or 5 hours...

Hesitation is still there when hot...

Could it be the timing? When I press the gas slowly on the highway I accelerate (sometimes it goes fast, other times its a little slower - but it does jump between the two if I hold the pedal steady) - If I really get on it, sometimes it GOES, most times it kinda is like meh... spools the turbo up and doesnt really go....

Any more ideas?

Josh

[AxiOn419]

Check for vacuum leaks. Make sure all of your intercooler piping is tight.

Did you do the test I had mentioned before? Take out the coilpack and spark plug that is on the cylinder that is not firing. Put the spark plug in the boot, touch the plug tip to the valve cover, unplug all the plugs to the other coil packs. Have someone else turn the car over and see if it is getting spark. That way you know if it is a spark/eletrical issue. If you are still getting spark then it may be a fuel problem.

[Acecool]

Could it be fuel if the car is working flawlessly when cold - since a cold engine requires more fuel... hot engine needs less.......

Maybe I should install my high fuel pressure pump, but um.. I need an adjustable fpr otherwise it will suck gas like no tomorrow!!!!

[AxiOn419]

So when you first crank the car after the engine is fully cooled it will crank right up and drive great, only when it comes up to temperature is when it bogs down?

If you can crank the car when it is cold and go wide open throttle and it runs great then that would rule out fuel issues as well as vacuum leaks. That is unless your fuel pump is overheating.

When I got my new s13 (stock ka24), I got it at a great price cause the guy did not know what was up with it and could not get it running right. I got it home, drive it for 10 minutes and once it got warmed up I would lose pretty much all power. After some further investigation I found out the gas tank had water seeping into it. The gas tank was rusting inside which I am assuming caused the fuel pump to overheat. The gas in the tank literally looked like watery mud. Swapped in my gas tank and fuel pump from my wrecked s13 and it ran like a champ.

Did you drive this car with the KA in it? How did it run? Have you checked the tank yet?

Or, as you mentioned before it could be the ignitor but that is why I have been asking you to run this test:

Take out the coilpack and spark plug that is on the cylinder that is not firing. Put the spark plug in the boot, touch the plug tip to the valve cover, unplug all the plugs to the other coil packs. Have someone else turn the car over and see if it is getting spark. That way you know if it is a spark/eletrical issue. If you are still getting spark then it may be a fuel problem.

[Acecool]

I pulled the ka out of this one... lets just say an hour and a half from Charleston to Charlotte - (avg 140mph) - it was the strongest running kae I have ever driven - no problems at all.. 0-60 in 7.8 seconds - stock is 8.8... only mods were intake and exhaust...

I just swapped the fuel pump for the walboro or however you spell it - high pressure blah blah blah.....

Absolutely no change in driveability... (Ahh, electric fans just turned back on after my drive...)

Same on highway, same on slowway - maybe a SLIGHT improvement, but not very much IF any at all.... (fans on again....)

So hmm.... I ruled out the e fans draining the alt, because I rewired them so they only come on when the engine needs them and that has been working great too - turns on and off now when car is off..... (lol on again....)

[AxiOn419]

Like I said, do the spark test.

I have to call you out on the 140mph average speed though, come on man.. come on..

[Acecool]

Charleston to Charlotte... Left at 7:30 AM arrived at 9:00 AM... 1:30 total time...

distance/time = average speed

[BoostFab]

Ok, turns out my 3rd cylinder coil isnt firing properly when hot... the coil is getting power, but when I unplug any other coil, the hesitation is 10x worse... if I unplug the 3rd one, then the hesitation is still there, no change....

Anyone have a spare rb20 coil?

Josh

time for gm coil conversion.zerothread?id=219934

if not; i have some extra coils, let me know if you need them

[Acecool]

Might be worth it, but scared of some of the responses about frying ecu and killing the engine...................

On skylineowners.com one guy suggested the mafs, so I will try cleaning it real quick with carb cleaner... Which could make sense, since the air is supposed to cool the element down to tell it how much air is going through... but it it is too hot (hot air in engine bay) then it will not read right....

Josh

[Acecool]

Well, I am getting spark...

Ill try using the old sparkplug on slot 3, it seems to have more of a gap.... densos.....

or i dunno.. im going to get a gapper thing from walmart...

[driftingmy240sx]

if you still have a cyl 3 misfire try putting the tip of a long screw driver on the injector and you ear on the other end and listen for it operating. i had a problem like yours due to a bad injector.

[Acecool]

Hmmm... It is a deatschwerks rebuilt injector!!!

Should still be under warranty if they provide a 1 year...

Ok, The ngk B6P or whatever sparkplugs that I got... should I have gapped them any different that what they were at?

Asking that because the Densos that came in the engine are gapped more than the ngk - but they have a finer tip....

I may throw a couple of those in real quick and see if that solves the problem before messing with injectors :-(

Josh

[AxiOn419]

The reason why your older plugs have a larger gap is because they have been worn down, hence the sharp tip. That is normal.

Gap your spark plugs to .8mm, that should be just fine for what you are running.

[Acecool]

No gapping tool, and no one is open right now :-(((((

Would the B6P or whatever plugs...

Here: BCPR6ES

wouldnt they be pregapped at .8??

Josh

[Acecool]

Ok, so I checked with a tape measure, and it looks like that are at 1mm

.8mm = 0.31 inches

so, maybe if I pushed it in a little on the first 3 cylinders it may help and I can test drive real quick to see if it makes a difference...

lol...

Getto until I buy the 99cent thing tomorrow...

EDIT:Or not.. weird arse tape measure....

Ok, so they are at .8............. various conversions done to convert tapemeasure inch to mm and all....

[AxiOn419]

I am running those same exact spark plugs. I dont recall them being gapped to exactly .8mm but anywhere from .8mm to 1.1mm should be just fine. A tape measure is in no way precise enough to tell you what they are gapped to, you need a tool.

Wal-Mart is open and they would carry a gapping tool.

[Acecool]

I was just at walmart and they didnt have it :-(

Maybe ill ride up to the one in north chuck real quick.......

Or wait until tomorrow, since they should be gapped pretty close to .8......

Maybe my injector... could it be timing?

Josh

[AxiOn419]

Could be timing but it seems like the issue would also occur on another cylinder since they fire at the same time. Not sure which one. Ignitor would be something to test, if you knew someone that had an rb20 that lived near you. You probably dont though. Take a ride down to Augusta and I will let you try my spare ha

So, write down a checklist of what you have tried and eliminated as the possible causes. Maybe someone else checking the thread can have a look and see something we are overlooking.

ECU could be another possibility but doubtful as it is working when cold. Is the ignitor grounded good? Did you clean the mafs?

Does your car sound like this when it starts acting up:

One cylinder is not firing:http://youtube.com/watch?v=Lg88XQht4WY

All cylinders firing:http://youtube.com/watch?v=iWODt-4WEoo

There is quite a distinct difference, which does it sound like?

[Acecool]

Sounds like the second - but SMOOTHER most of the time.. but when hot it sounds like the first one and yeah... maybe I should take a video real quick....

Lemme find out how to mount my camera in the car real quick and ill take it for a drive with this ngk plug, or actually let me drop an old plug in that cylinder...

Josh

[AxiOn419]

The reason that second video has a bumpy sound to it is because the car was backfiring quite a bit as you can tell. That was taken after all the cylinders were just about flooded with gas.

It would be really nice if you could test it with another ignitor. Yours may be getting really hot and acting up.

You could try this: Run the car until it starts acting up, once it does, park it real quick and throw a clean plug in the cylinder. Though it is not recommended to pull hot plugs you should be alright. Once you put the clean plug in, drive it again with it acting up. Drive it for a minute or two then park it and pull the plug. Check to see whether the plug is wet, dry or burned. If it is wet and not burned at all.. then its a spark issue. If it is dry and not burned then it sounds like a fuel issue. If it burned and looks like the rest then .. head gasket? But then again it runs good when cold..

Has this engine been compression tested?