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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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 Posted: Mon Jun 06, 2005 5:34 am Post subject: Ka-t problems |
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Well it runs but I have some issues. Here is my setup:
Rebuilt motor
Forged pistons 9:1 compression (CP)
Forged rods (Crower)
Cometic thick (.043) head gasket
Nissan 370cc injectors, cleaned and balanced (RC engineering)
New T3/T04e 57trim 63A/R
Tial 38mm waste gate with 5.9lb spring.
Walbro 255 lph fuel pump on stock wiring
Knockoff TurboXS H-34 bypass valve re-circulated from hot side of the intercooler to behind the maf
Innovative Wideband
Apexi Safc
Apexi SITC, Timing retarded 4 degrees from 2000rpm to redline.
Timing set to 20deg, checked with timing light
Idle speed ~700rpm
Fidanza lightweight flywheel
Act extreme clutch kit
The engine was run in for an hour NA and has had an oil change with 5w30 synthetic. I went out to tune the car last night; I slowly worked my way up through the revs since the engine has practically no miles on it. I tuned the SAFC to -19 across the board, which gave me 10.5-11 AFRs when on the throttle and in boost (~5lbs) all the way up to redline. At cruise and idle she was sitting at about 14 AFR, and I could see the O2 cycling rich-lean to for the ecu to learn the fuel settings. The first and major problem is the engine dying on its way down to idle. If I let it drop from 3k or so it will dive 500 or so and die. If I let it come down easy it will go to 500 then bounce up to 1000, dive back to 500 and may eventually stabilize and stay running. The AFRs cycle between 14 and 11 while doing this. Any Ideas as to what settings or lack there of (Decel Air?) could be causing this?
I am planning to do a vacuum test on the system as soon as I get a pvc plug to fit in place of the maf.
Plus, I am unsure of a few of the vacuum lines. There were three lines hooked up to the intake before the throttle body (image of an Apexi cold air intake install from 240sx.org):
The one with the yellow star is the crankcase vent which I have vented to the atmosphere through a filter. The one with the hand on it I believe is the lower breather tube which is connected to the cold side of the intercooler piping (see red radiator hose below). I do not know what the small line near the index finger is but I have that connected before the turbo and after the maf (see the line running next to my radiator cap).  I have a FSM but it is unclear, any help on where these lines should be connected would be greatly appreciated.
Another problem: the thermotec heat shield kit on the turbo and down pipe melted the aluminum off itself. 
Is this due to the crappy nature of this kit or were my egt's too high when I started boosting? The correction was at -27 for my first few pulls which put the AFs in the 12 or so range.
Sorry for being so long-winded, in retrospect she pulls hard when on boost so I am happy with the performance, I just have a few problems to sort out. Please let me know if there are any questions, and Thanks
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC
Last edited by LigouriRd. on Wed Jun 15, 2005 4:59 am; edited 2 times in total |
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Z16A
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Joined: 01 Apr 2005
Posts: 10
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| Posted: Mon Jun 06, 2005 8:29 am Post subject: |
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raise the idle! a lot more crap to try and pull air throu. get rid of the emissions **** 
once again tumble weed emoticon
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"how about i give you the finger and you give me my phone call" |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Mon Jun 06, 2005 8:57 am Post subject: |
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Dan stay out of this, or at least tell me something I don't know
...joking
By the way this is the guy who rode along during the tune and helped me adjust the AFC while reading the wideband, Thanks
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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nissanfanatic
KA-T.org Featured Ride
Joined: 20 Nov 2004
Posts: 4969
Location: Jax/G-ville/the ocean
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Mon Jun 06, 2005 3:03 pm Post subject: |
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Actually with the exception of changing the oil to synthetic after the third run oil change that is exactly the proceedure that I performed. I read from another source that the forth and further breakin is better performed with synthetic...buut they could be wrong.
| Quote: | | Knockoff TurboXS H-34 bypass valve re-circulated from hot side of the intercooler to behind the maf |
-self explanatory
Um, the instructions that came with the heat shield kit detailed the installation exactly as shown here:
The shield is right over the turbo.
Keep the info coming, please.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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nissanfanatic
KA-T.org Featured Ride
Joined: 20 Nov 2004
Posts: 4969
Location: Jax/G-ville/the ocean
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| Posted: Mon Jun 06, 2005 6:50 pm Post subject: |
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Okay. Its just that you said the engine was run an hour NA before you changed to syn.
I also thought you bought the Thermo tec adhesive backed heat shield.
My bad on both.lol
Strange problem. Could very well be vacuum related. Do you have a boost/vac gauge? Even NA 240s seem to hava an idling problem eventaully. I would actually try turning the idle up a lil. My car does a very similar thing when I have the screw adjusted too far in. I loosen it and it will sit at 900 and won't drop too bad. But I'm VTA. Give it a shot. Worst thing that can happen is it works..
_________________
-Cory
1992 Nissan 240sx KA24DE-Turbo
2000 Honda S2000
IMTMO-Manufacturer of quality racing and motorsports enthusiasts since 1996. |
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Projex240
Encyclopedia-Nissan
Joined: 01 Apr 2004
Posts: 1049
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| Posted: Mon Jun 06, 2005 7:45 pm Post subject: |
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Sounds liek you have the same problem I and about a hundred other people do in ka-t land. Your IACV is a little lazy. When cruising that high and letting the revs drop so quickly, the IACV that is used to moving much less air cant really keep up due to being sluggish and gooped up from years of useage. Take it off, clean it and put it back on. Hopefully that would help.
ALso, that lien you have your hands on is the IACV hose. Spray an entire can of carb cleaner into it with someone sitting in the car holding the revs up so ti doesnt stumble and die while having it disconnected. It may help it may not. If not, see above what I said.
Good luck!
-Josh |
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Z16A
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Joined: 01 Apr 2005
Posts: 10
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| Posted: Mon Jun 06, 2005 8:13 pm Post subject: |
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| Projex240 wrote: | Sounds liek you have the same problem I and about a hundred other people do in ka-t land. Your IACV is a little lazy. When cruising that high and letting the revs drop so quickly, the IACV that is used to moving much less air cant really keep up due to being sluggish and gooped up from years of useage. Take it off, clean it and put it back on. Hopefully that would help.
ALso, that lien you have your hands on is the IACV hose. Spray an entire can of carb cleaner into it with someone sitting in the car holding the revs up so ti doesnt stumble and die while having it disconnected. It may help it may not. If not, see above what I said.
Good luck!
-Josh |
if the carb cleaner thing is to clean out some deposits hes already sea fomed the engine so i dont know if that will help any than the sea foam has.
we raised the idle tonight to 820-850 so its doing better imo but it still will backfire/go rich and pop and then die sometimes.
cleaning the idle air control valve is another good step so we'll see if he gets it done quick enough.
i'm thinking he should cap off the one line going to the intake pre turbo and seeing if the engine will throw a cel. find out soon enough
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"how about i give you the finger and you give me my phone call" |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Tue Jun 07, 2005 4:09 am Post subject: |
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Hey dan, remember when you told me to completely clean out the intake manifold and all the stuff connected to it...yeah, I didn't get to that. This intake manifold hasn't been sea-foamed. Gotta do that.
I do have a vacume/boost gage, the engine sits at -20 at idle. I think I still need to perform a pressure test on the entire intake system to make sure I have no leaks.
Thanks so far guys
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Wed Jun 08, 2005 4:36 am Post subject: Update |
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Well on the advice that the IACV might be sticking, I seafoamed the crap out of it. It seemed to make an improvement, the engine drops to about 500 rpm but then the IACV catches it, raises the idle to 1000 then settles to 850-900 where I adjusted the idle to a few days ago. It does not come even close to stalling as long as I am only dropping the revs from 4k or less. The problem still lies that if I drop from 5k or so to idle it dives below 500 there is a loud back fire and the engine dies thereafter. So it seems to me that its getting too rich on the climb down to idle. Right now the correction is -27% at 800 and 1200 rpm. The stalling gets worse if I decreas the correction (the rest of the map is a -19% or so). Do yall think that using the Decel air will help any? Regardless I will try setting that tonite. Could it be that the bov (which is 6 inches behind the maf and angled toward the compressor) is blowing out though the maf and causing some extra fuel to be added?
Ps: My sister was complaining that the occasional backfire was keeping her from falling asleep. This was at 9:00pm and she gets up to go to work an hour after I do. Wah frickin wah, I don't wanna hear her and her live in boyfriend fooling around while I am home either...yeah I live in a white trash household.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Fri Jun 10, 2005 4:48 am Post subject: |
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Well I ran though the Safc Decel air using this setup http://forums.freshalloy.com/ubbthreads/showflat.php?Cat=&Board=UBB9&Number=67773668&Forum=All_Forums&Words=Dec%20Air&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=1year&Main=67772932&Search=true#Post67773668
It definitely helped with the back firing, but as the engine warned up the mixture started to go way lean. When I dropped from 4k-ish the rpm would stabilize quickly then drop to 700 or so and the engine would run real rough (16-18 afr). I am going to try Structure's setup next and see if that works better (http://forums.nicoclub.com/zerothread?id=119966)
Before I ran though this I pulled all of the plugs and regapped them to .035. The #1 and #4 were black from carbon
 . Cylinders 2 and 3 had oil on them:
Could this be due to the rings not seating yet and a little blowby or am I fooked on this rebuilt engine? Should I go back to dino-oil to let the rings seat some more. I spoke with an Engineer formerly with Saturn who claimed that synthetic or dino basically have the same film viscosity and it wouldn't make any difference to the rings seating.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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Z16A
Learners Permit
Joined: 01 Apr 2005
Posts: 10
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| Posted: Fri Jun 10, 2005 6:51 am Post subject: |
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not supposed to gap iridiums "ruins the tip". buy coppers and be done with it.
did you wipe the oil off 2 and 3 and then put them back in so we can check again? you would really need to run the car and then check the plugs for condition. we could always do a compression test if need be.
p.s. nice try on the tumbleweed. i'm doing it the right way thou and having pawel send me a tumbleweed. then i'll record a small video of it rolling/bouncing by and post it everytime i feel the need. you can be assured there will be different variations of the video.
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"how about i give you the finger and you give me my phone call" |
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flip240
Belongs To The TOP CONTRIBUTING MEMBERS!
Joined: 19 Aug 2004
Posts: 1844
Location: Chicago, IL
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| Posted: Fri Jun 10, 2005 7:47 am Post subject: |
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I'm not sure... but do you know if its because you have a filter on the PCV?? The air leaking out is metered so its running richer than it should?
_________________
- Phil - Concord Gray S14 -15 psi, 309 rwhp / 368 ft-tq
Daily driven turbocharged KA24 for 5 years and counting.
My setup: KA24DE-T |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Fri Jun 10, 2005 9:31 am Post subject: |
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That filter is on the crankcase vent. The pcv is still connected. I finally did a pressure test, the entire system (with the exception of the cheap-charlie- chinese bov) can hold 10 psi.
I didn't close the gap down completely on the plugs, just closed it to around .035 cause I didn't want to screw up the tip. I cleaned up all of the plugs before I put them back in so I can run a bit this weekend and see how they are affected. And yeah Ill get some damn coppers (BKR6ES-10), one step colder than a stock equivalent copper.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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flip240
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Joined: 19 Aug 2004
Posts: 1844
Location: Chicago, IL
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| Posted: Fri Jun 10, 2005 7:29 pm Post subject: |
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(BKR6ES-10), one step colder than a stock equivalent copper.
Are you a SOHC?
You're in Chicago? hit it up yo!
_________________
- Phil - Concord Gray S14 -15 psi, 309 rwhp / 368 ft-tq
Daily driven turbocharged KA24 for 5 years and counting.
My setup: KA24DE-T |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Mon Jun 13, 2005 4:27 am Post subject: |
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Nope, DE engine. I thought that for every 100hp you should go one step colder on the spark plugs. Granted I am not at 100hp yet, but the my setup at 7psi should yield that number.
Update: I think I figured out why the Decel-air was driving the engine lean at idle. I had the first ne point at 800rpm which was almost lower than my idle. I think that the SAFC interpolated the airflow curve too lean when below the ne point . Once I moved the NE point up to 1000 and the airflow accordingly she idled fine...
That was until yesterday when she started idling like crap again regardless of having the decel air on or not. I believe there is something wrong with the IAC. If the rpms come down too fast and dip below 500 the it sits there bouncing between 1000 and 500 and never settles. I had the idle set to 800 but it has since dropped to 700 and runs rough. I tried raising the idle back to 800 again and it seemed to help but I havent driven it anymore after that.
I managed to pick up a cylinder 3 miss-fire code while out cruising on saturday. I pulled the plugs again to find 3 black with carbon and all the rest slightly white=normal. I cleaned #3 but it didn't help the idle. I'm definitely getting some new plugs, now which ones?
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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flip240
Belongs To The TOP CONTRIBUTING MEMBERS!
Joined: 19 Aug 2004
Posts: 1844
Location: Chicago, IL
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| Posted: Mon Jun 13, 2005 8:17 am Post subject: |
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Have you checked all your plug wires?? I was having some cylinder misfire b/c the insulation on one of my wires was torn..
I've been running BKR7Es.... gapped to 32, but I don't think it should make that much of a difference...
_________________
- Phil - Concord Gray S14 -15 psi, 309 rwhp / 368 ft-tq
Daily driven turbocharged KA24 for 5 years and counting.
My setup: KA24DE-T |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Tue Jun 14, 2005 4:03 am Post subject: |
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Well, I replaced all the plugs and wires. No misfire so far but I haven't driven it around yet.
The idle hasn't improved, matter of fact it won't even start without giving it a lot of gas. I followed the fsm's settup for adjusting the idle (with the tps unplugged) but set it at 900. When the tps gets pluged back in the idle drops to 700 and its real rough. Is this a symptom of a bad IAC? Im gonna try to swap the IAC from the other engine and see if it improves...if I can get the dang thing off without removing the entire intake manifold.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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LigouriRd.
Encyclopedia-Nissan
Joined: 19 Oct 2004
Posts: 1040
Location: Edgerton Wi.
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| Posted: Wed Jul 06, 2005 5:05 am Post subject: |
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Well, she's running pretty well now after I replaced the IAC with one I cleaned from the '96 motor. After I let her warm up the idle was at 700rpm or so. I unplugged the tps and it bumped up to 1000 so I left it alone.
Drove around for an hour or so last night, no misfire codes, hell no codes at all. I am getting a pretty constistent backfire as I decelerate in gear to around 2000 rpm but it doesn't die as long as the decel air is turned on. The A/F goes extremely lean (~20) right before it back fires. This doesn't sound normal to me.
I did a pressure test before I started it up and I heard a leak from what seems to be the diaphragm in the egr valve (solenoid?). I guess that is another thing that I have to replace.
_________________
"There is no such thing as too much boost. You could have too little rod, piston, sleeve, head gasket or timing. But never too much boost."
'91 Nissan 240SX
'96 Nissan 240SX KA-T(<link)
'04 Mazda 6s, 5 door
'85 Honda Nighthawk 450SC |
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Z16A
Learners Permit
Joined: 01 Apr 2005
Posts: 10
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| Posted: Wed Jul 06, 2005 5:21 am Post subject: |
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don't replace it. just put a plate between it and the manifold. or just put the plate on it alone.
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"how about i give you the finger and you give me my phone call" |
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