I've got big problems.

[AmoebAssassin]

So I recently got my car on the road running and reliable, but about 3 days ago a problem surfaced.

See, it feels like clutch slip or a locked caliper, but im not sure of either. I'm getting full boost, (8-9psi) the turbo spools normally, the car sounds the same (loud), and the RPMs sound like they are increasing. But the car just doesnt feel like it is accellerating, as if there is no power or power is getting lost somewhere. It also seems as though the car is faster or more responsive at partial throttle than at full throttle, like if I floor it and it feels like the clutch is slipping, and I bring it down to 3/4 throttle, the car will feel faster.

I'm really worried that the clutch is slipping (cusco super single). I didn't have it properly surfaced when I replaced my damaged clutch disk (old clutch material removed w/ orbital sander and a very, very steady hand. No metal came off, just old clutch material. Also, I got very hasty on my clutch break-in and didn't really go easy on the motor at all for the reccommended 400-500 miles.

I'm tempted to say that it's clutch slip, except for a few things. One, I can't smell clutch AT ALL when this happens. I'll let it run where it feels like its slipping all the way up a hill, then park it immediately and put my nose under the car, and I dont smell clutch at all. I don't see any smoke coming from the transmission (which would happen if I burnt my KA clutch). I'm certian its a carbon-metallic disk, but I would still smell the burning binders, wouldn't I?

Secondly, If I drive the car such that the clutch feels like it's slipping, and suddenly let off the gas, the clutch shows no sign of slippage. If the clutch was slipping, one would assume that the engine RPMs would fall disproportionately to car speed until the clutch "catches," at which point the RPMS would drop with car speed. This is not the case, when I accellerate and it feels like it's slipping, and I let off the gas suddenly, the RPMs fall with the vehicle's speed immediately after the throttle is released; there is no "slip and catch" going on.

Thirdly, I tried driving up a hill in 4th gear and kicking the clutch, and I don't detect any slip at all, the car jumps violently and the tach drop IMMEDIATELY.

I dont think it's stuck brakes either, because none of the brakes feel overheated when i place the back of my hand near the rotors, and the pedal feels fine and isnt fading.

I just don't know what to do. I really don't want to have to change my clutch and flywheel because I have two stripped flywheel bolt holes that I repaired with timeserts, but it really feels like cltuch slip. Is there anything else this could be?

[ILikeMy240sx]

Power loss...

I would check the basic things before I start pointing to the clutch.

Timing and boost leak and TPS contribute alot to your motor making proper power. I would check on those three.

I remember when my car ran, it idled fine and all but it had absolutely no power due to boost leak and timing being off. It was almost slower than my KA.

[AmoebAssassin]

I drove it again just now and it is not the clutch. The problem is not evident until the car has been driven for maybe 15-20 minutes. Then it just has massive power loss. It's not a rough power loss like a speed cut or rev cut, just...it's got no balls. Also it pops a little more on declleration when this happens, but that could be because i just put some STP fuel injector cleaner in it. Does anyone have any ideas?

I don't think it's timing because the engine runs great until you drive it for 10-20 minutes, then its just a dog. Still loud and all, but it just doesnt accellerate to match the increase in loudness.
Modified by AmoebAssassin at 1:27 PM 8/21/2006

[Luke]

This is a very general symptom, but I've got the same problem. I'm suspecting boost leaks. I've already checked timing, tps and replaced the coolant temp sensor. I've got to pick up some new IC couplers... Repost if you find any good solutions.

[AmoebAssassin]

See, the thing about this is that it's not running like crap all the time, just when it's been driven a while. So i dont really know if boost leaks, timing, or something comparable is to blame.

I'm pretty sure it's a sensor, but I have no Idea where to start on this one.

[nzmoman]

is your diff making any noises, or is it leaking at all?

[Luke]

See, the thing about this is that it's not running like crap all the time, just when it's been driven a while. So i dont really know if boost leaks, timing, or something comparable is to blame.

I'm pretty sure it's a sensor, but I have no Idea where to start on this one.

Same thing here. It can run great for about 10-15 min depending on how hard I am on it. then form there on, it runs like pooo. I've given it full throttle, while slipping the clutch, with hardly even a squeek. I thought I was having a major clutch problem, but it seems the clutch grabs OK most of the time. I've already been through 3-4 clutches since I got the engine oh 3 years ago.

[AmoebAssassin]

is your diff making any noises, or is it leaking at all?

I do have gear whine, but im 90% sure that it's transmission noise as it varies with engine input speed.

I need to drive this car across PA this weekend, so i have to solve this problem ASAP!!

[KAestate]

See, it feels like clutch slip or a locked caliper, but im not sure of either. I'm getting full boost, (8-9psi) the turbo spools normally, the car sounds the same (loud), and the RPMs sound like they are increasing. But the car just doesnt feel like it is accellerating, as if there is no power or power is getting lost somewhere. It also seems as though the car is faster or more responsive at partial throttle than at full throttle, like if I floor it and it feels like the clutch is slipping, and I bring it down to 3/4 throttle, the car will feel faster.

When you say the RPMs sound like they are increasing does the tach correspond to that sound or is it JUST the sound. IMHO it seems to be an air/fuel mixture problem. If the boost stays steady at 8-9psi before and during your symptoms then you can rule out wastegate, IC and turbo.

Oh, and if it is a full Kevlar clutch you won't necessarily smell a thing if it IS slipping.

[AmoebAssassin]

I looked again and no, the tach does not correspond to the sound, i.e. the clutch isnt slipping. If im accellerating when it feels slow, it's at the same RPM at a given speed as if it was cruising at that speed and not accellerating, so I know the clutch isnt slipping on accelleration.

What it is is a HUGE loss of power after the car has warmed up. I was going to check for boost leaks but my gauge still shows the same boost I always get. I don't think it's timing either because the car is pretty quick when it's just warmed up and until you drive it for 15 minutes or so. If timing was off it'd be slow all the time, right?

BTW the disk is ceramic/metallic, so it's got metal and ceramic particles, but they still use a binder to hold the particles together...tahts what you smell when you burn clutch, and I don't smell anything other than exhaust under the car.

[ILikeMy240sx]

Try replacing the coolant temp sensor for ECU. Its like 13 bucks at autozone.

[AmoebAssassin]

Will try that today, I'm assuming it cross-refs with the KA24DE?

Also, is this what ignition breakup feels like? Because I may need new plugs and such.

[ILikeMy240sx]

I got mine from a 91 Sentra SE-R. (Coolant Temp Sensor)

Your temp switch for your gauge would be your chassis dependent.

Ignition break up would feel more like the rev is skipping or something. More like hitting the rev limiter... usually the car burps and farts

[AmoebAssassin]

I just drove it again and this happens at anything greater than like 10 percent throttle. It'll drive fine at 10 percent throttle or so but hte second i punch it, it gets really lame and slow. If i back the throttle down to about 10 percent again, it'll drive like it's supposed to (and quicker than it is when I punch it).

The problem still seems to come and go the more I drive the car, i.e. it wont show when the car has just been started and brought to temp, but after 10 mins it happens.

Ilikemy240sx, I guess it isnt ignition breakup then. I'll switch the CTS and see how she behaves.
Modified by AmoebAssassin at 7:17 AM 8/22/2006

[ILikeMy240sx]

sounds more like a boost leak but it is funny that it happens only when you drive it for 15 mins or more.

I have a feeling CTS might not solve your problem but its worth a try for 13 bucks. When that sensor is gone, your car will run like poo.

[AmoebAssassin]

It won't kill me to tighten up all my clamps too. I'll let you know.

Btw Ilikemy240sx, thanks so much for the ongoing help, you're a big asset to the SR community on NICO

[ILikeMy240sx]

no problem. I just wish I could be more helpful by being there and poking around the car with you but oh well :-)

[xsublimefrekx]

Have you checked the plugs. I know it sounds off but i had somewhat of the same problem and i need to replace my plugs. Then again i was shooting flames out the back of the car.

[ILikeMy240sx]

I dont think he is experiencing spark prblems.. He will backfire, stumble and hear something isn't right if it was spark issue.

But seems like car sounds ok.. no backfiring, stumbling, popping, etc etc. just no power.

[ILikeMy240sx]

BTW, when CTS doesnt fix..

Id poke around in the ECU to see if you have any codes.

Then check for TPS voltage output and Knock sensor. Make sure the connector for the knock sensor is in good condition and such.

[AmoebAssassin]

Correct, the car does not backfire violently or shudder/jump, it just loses the ability to accellerate. Still builds boost great and the clutch isnt slipping, so i'm stumped.

Although it does make light pops from the exhaust slightly more when it's acting up?

[AmoebAssassin]

What is the procedure for getting the error codes from the ECU?

[ILikeMy240sx]

yeah its probably getting more pops since you are running more rich -> no power.

Turn the key to on. Look at your ECU and you should see a screw that you turn. Turn it clockwise fully. Wait 2 secs, turn it counterclockwise fully. you should see the LED next to it blink. Declipher the code.

ex) Code 55 would be 5 long blinks followed by 5 short blinks. this means ECU doesnt detect anything.

BTW, after you pull the code you repeat the clockwise and counterclockwise to get it out of the diag mode.
Modified by ILikeMy240sx at 12:32 PM 8/22/2006