# Clutch grabs too quick and forcefully



## TWX (Jan 29, 2010)

So, a neighbor is selling me his 86,000 mile '95 King Cab XE 2.4L 4x2 manual. Among its problems is a clutch that goes from fully disengaged to fully engaged with very little pedal travel. Frankly it's undrivable and I have no idea how he put up with it for so many years like this.

It does not seem to be slipping, in fact it's quite the opposite, it jumps when trying to start because it's fully engaging before one expects it.

I've read on this forum about issues with the dampener. Beyond bleeding that or bypassing it is there anything else that I should check?


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## jp2code (Jun 2, 2011)

That sounds like the clutch is worn out.


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## smj999smj (Jan 1, 2006)

Check for leaks at the slave cylinder and the back of the clutch master. Usually when the slave is leaking, I'll go ahead and replace the clutch master, anyway. I honestly never encountered a bad clutch damper in all the years I worked for Nissan (16) nor on my own Nissans. Maybe I've just been lucky or maybe that's a sign that they don't fail very often? It's kind of hard to diagnose your problem without actually being able to experience it for myself.


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## TWX (Jan 29, 2010)

*nod*

I'll check for leaks. Unfortunately the motor appears to be leaking a bit at the rear-main or else the minor valve cover gasket leak is making its way down to the transmission, the front lower edge is greasy enough that it may be hard to tell if it's DOT3, or oil, or a combination of the two. Probably going to have to do the rear-main while the transmission is out.

At least I have a '94 factory service manual to operate from.


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## TWX (Jan 29, 2010)

Okay. Some backstory...

He overheated it pretty badly. Upper radiator nipple broke off and drove it basically dry. Shop had quoted him a lot of money to fix it, so he sold it to me, he had to get the title squared away and that took some time, I fixed the cooling system today and changed the oil and filter. It starts but it idles a little odd, dropping down in RPM. What's really weird is that the tach on the dash does not seem to always be synchronized to engine RPM. Road-testing it's a little weak, and RPM dropped dangerously low coming off-throttle to idle. When I had compression-tested he cylinders after it arrived I got pretty good results, 150-150-145-150 psi across the four cylinders, haven't tested it again since fixing the cooling system.

I figure this other stuff is not related to the transmission, but I need to correct it anyway. Any suggestions as to what to check first? I'm thinking there's some kind of sensor fault causing the RPM to not be displayed correctly on the dash, or there's an electrical fault somewhere.


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## jdg (Aug 27, 2009)

TWX said:


> He overheated it pretty badly.


That's the start of a bad backstory right there.



> When I had compression-tested he cylinders after it arrived I got pretty good results, 150-150-145-150 psi across the four cylinders, haven't tested it again since fixing the cooling system.


Was that on a cold engine or hot?
May not have warped the heads or wrecked a head gasket, but if he "over heated it pretty badly", I'd put money on some piston ring damage...if not damage, then at least some significant wear that would likely show up if a compression check is done with a hot engine. Yes...yes...yes...normally compression numbers would come up on a hot engine as the parts expand to their normal operating dimensions and all that.

How about your basic tune up? I'll bet the plugs probably didn't appreciate a good overheating.


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## jp2code (Jun 2, 2011)

If the engine isn't running right, just pull the codes to see what needs attention.


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## TWX (Jan 29, 2010)

jdg said:


> That's the start of a bad backstory right there.
> 
> 
> Was that on a cold engine or hot?
> ...



When I compression-tested it before I did it cold, after it had been sitting for many days, without squirting any fresh oil into the cylinders.

I tend to hoard, I may have the plugs laying around from when I did a plug/wire change on my current 171,000 mile 95 HB, will look. Barring that I might even pull the plugs out of the higher-mileage truck to test 'em in this one.

I'm trying to avoid spending too much money on this engine in case the bottom-end is cooked. Would rather spend that money on a new longblock or a good junkyard pull from a truck that was junked because of a car accident.



jp2code said:


> If the engine isn't running right, just pull the codes to see what needs attention.


I'm assuming that it's the, "pull the seat, turn the idle-speed screw on the side of the computer, watch the LED" procedure?


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## jdg (Aug 27, 2009)

TWX said:


> When I compression-tested it before I did it cold, after it had been sitting for many days, without squirting any fresh oil into the cylinders.
> 
> I tend to hoard, I may have the plugs laying around from when I did a plug/wire change on my current 171,000 mile 95 HB, will look. Barring that I might even pull the plugs out of the higher-mileage truck to test 'em in this one.
> 
> I'm trying to avoid spending too much money on this engine in case the bottom-end is cooked. Would rather spend that money on a new longblock or a good junkyard pull from a truck that was junked because of a car accident.


Exactly ONE oil pressure check with the engine warm will tell you all you want to know (or don't want to know).


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## jp2code (Jun 2, 2011)

TWX said:


> I'm assuming that it's the, "pull the seat, turn the idle-speed screw on the side of the computer, watch the LED" procedure?


Yes, sir!

Here is the procedure:

[VIDEO] Checking Error Codes - Infamous Nissan - Hardbody / Frontier Forums


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## TWX (Jan 29, 2010)

Went ahead and bought plugs, the autozone will price-match, to an extent, Rockauto. Got the NGK Platinums. Also bought an air filter and a couple of cheap oil filters, I expect I'll do something to flush the oil so those filters will be necessary.

I've read-up on testing the MAF sensor but before I do that I'll pull the passenger's seat to pull codes. If I need to test the MAF sensor I'll have to get the engine warmed-up anyway, so may as well compression-test it again warm and change the plugs at that time.


The idea of a KA24*D*E swap is interesting, but based on what I've found it seems like if you have a '95 or older it's going to be a lot more work than it's worth with the vast electrical and ignition differences, and if you have to ask for a lot of help then you probably don't have any business doing it.


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## TWX (Jan 29, 2010)

Pulled the seat, got code 43 in third mode on the ECU. Looks like something may be up with the throttle position sensor.

Curiously the idle-speed screw was turned all the way down. On my higher-mileage truck I've got it idling around 1000RPM. Might adjust it up on this one before I put the seat back in.


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## jp2code (Jun 2, 2011)

The idle switch could be bad or could have a bad connection.

Get a service manual for your year truck by following link in pic below. This site will not let me post the link to that site.


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## TWX (Jan 29, 2010)

I've got a '94 factory book, I'm studying it now. Stupid shop computer sound just quit, so nice when that happens while pausing a youtube video to walk over to the truck to compare pictures...


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## jdg (Aug 27, 2009)

TWX said:


> Pulled the seat, got code 43 in third mode on the ECU. Looks like something may be up with the throttle position sensor.
> 
> Curiously the idle-speed screw was turned all the way down. On my higher-mileage truck I've got it idling around 1000RPM. Might adjust it up on this one before I put the seat back in.


Idle-speed screw all the way down, as in throttle plates all the way closed?
If so, that's a sign of a bit of a vacuum leak.
See how low you can get it to idle. If you can't get it to basically die, then I'd say you've got a decent vacuum leak somewhere.


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## TWX (Jan 29, 2010)

jdg said:


> Idle-speed screw all the way down, as in throttle plates all the way closed?
> If so, that's a sign of a bit of a vacuum leak.
> See how low you can get it to idle. If you can't get it to basically die, then I'd say you've got a decent vacuum leak somewhere.




Sorry, turned all of the way down on the computer. When it's not doing DTC feedback it's setting idle speed. If I understand its function correctly.


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## TWX (Jan 29, 2010)

Ok, found a video describing backprobe-testing the TPS:

https://youtu.be/_skVHdgtMTU

It's not Nissan-Hardbody specific, but I was able to identify the pink/red wire as hot, the black wire as ground, and the middle white wire as what must be providing feedback to the computer.

My meter is auto-ranging, so there was a hiccup as it switched from three significant digits past the decimal to two around the 3V mark, but otherwise it transitioned smoothly. Low/idle is 0.573V, high/full-throttle is 4.09V. Hot-to-ground bypassing the TPS had measured 5.13V.

Unless these ranges are off I don't think that the throttle position sensor is actually bad. Admittedly this was a cold engine, but I expect the computer to choose whether or not to believe TPS based on its reading of the coolant temperature.

EDIT: I suppose I should add that I could hear what I think is the closed throttle position switch doing its thing as I worked.


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## TWX (Jan 29, 2010)

Dammit, when pulling the plug wires to do the compression test and plug change, the boot pulled off of the electrode on #2. that might not be the only problem, but gotta fix that before I can do any other diagnostics.


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## TWX (Jan 29, 2010)

Ok, compression test, warm engine, plugs all out, fuel pump relay unhooked - #1-155psi, #2-160psi, #3-155psi, #4-165psi.

Onward to new plugs...


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## jp2code (Jun 2, 2011)

Be sure to use NGK, not Champion, or the engine won't run right.


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## TWX (Jan 29, 2010)

I went with the NGK Platinums.

Got it buttoned-up enough to road-test.

First couple road-tests were rough. CEL came on first time briefly, longer/stayed on second time. Got home and looked up Diagnostic Mode 5 on the computer. Started it, set that mode, drove it about ten miles and didn't get a CEL or error on the computer LEDs at all.

It still didn't idle as nice and even as I'd like, it was stronger/faster first half, but idle speed and consistency dropped a bit toward the end of the long road test. It was strong at very low RPM but felt weaker than the other truck at higher RPM, like on the freeway. Not that the other truck is exactly rarin' to go when at 75 miles per hour in fifth gear, but this one was just a little less-so.

What really caught me off-guard was a bit of a booming sound. Turns out it's the damn bed. The old one has a plastic slide-in bedliner, this one has a spray-in. The AC doesn't work in either, so I'm used to driving with the extended-cab and rear windows open. Not as much of an option with this truck if I can't find a way to quiet it down.

Figure I may as well vacuum-out the interior while the seat's out, then bolt everything back down and reinstall the underside air deflector.


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## jdg (Aug 27, 2009)

TWX said:


> Ok, compression test, warm engine, plugs all out, fuel pump relay unhooked - #1-155psi, #2-160psi, #3-155psi, #4-165psi.
> 
> Onward to new plugs...


Crap...it was worth a shot.
At the very least now you're almost 100% sure the rings and cylinder walls are in decent shape.


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## TWX (Jan 29, 2010)

jdg said:


> Crap...it was worth a shot.
> At the very least now you're almost 100% sure the rings and cylinder walls are in decent shape.


Just road-tested it again after vacuuming and scrubbing the interior. Still a little uncertain idling, but not nearly as bad as originally. Old plugs were pretty toasty so probably wise to have done them and the plug wires.

The tach not working right still bothers me. Donno if the problem is at the cluster, in the wiring from the computer to the cluster, in the wiring from some sensor to the computer, or some sensor. I'd expect it to be some sensor just out of the rough idle.

There are a lot of little rattles I'll have to go through. It's been in three minor accidents, Driver's rear quarter at the bumper was bent when I first met the neighbor that sold it to me, then he bumped something and bent the bumper into the front passenger's fender, then he backed into a bollard with the passenger rear corner, caught the edge of the bumper side, slid into the corner, broke the tail light, and bent the corner under the tail light a little bit. Fortunately for him I had a taillight so we just fixed it enough to be legal. I wonder if the two corners are just tweaked enough to make that bed floor act like a drumhead, which would explain the booming. Smacking the top of the bed rail from from the cab-back in steps makes the noise worse as one gets toward the back of the truck.

I guess I should be looking at that clutch and possibly at the rear-main seal before long. Also have a valve cover gasket but on closer inspection it looks like a shop fixed it when it was leaking by using a whole tube of RTV. Not sure I want to crack that open if it's not actually leaking.


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## TWX (Jan 29, 2010)

Update, a couple of miles into my morning commute the CEL came on and stayed on. Turned around and parked it at home and took a different vehicle.

Just checked codes, got 32, EGR FUNCTION, no other codes, and I had cleared the codes over the weekend and hadn't thrown another CEL until this morning.

My question, is this a pretty realistic indicator that the EGR valve is actually bad, or are there other things that can cause this DTC? It's been a long time since I had to replace a bad EGR valve and it wasn't on a Nissan, I think these symptoms are similar but again, been a long time. Also, since the EGR valve probably isn't something that's easy to swap between the two trucks I'm disinclined to swap to test.

I swear one of these days we'll actually get to bleeding the clutch and further clutch diagnosis if I can get the rest good...


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## smj999smj (Jan 1, 2006)

I've seen a few EGR valves stick open on KA engines, but an EGR function code can be caused from anything in the EGR system, from a vacuum port clogged with carbon or a leaking vacuum hose to a bad EGR control solenoid. A factory service manual has the diagnostic steps to isolate the cause of the code.


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## TWX (Jan 29, 2010)

*nod* I'll go through the troubleshooting guide.

Some buddies were suggesting, given the overheat, that I should do a leakdown test. Seems like it might be quite a bit of work in that I have to manually get the engine to TDC on each cylinder in-turn to ensure that the valves are closed.


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## TWX (Jan 29, 2010)

Heh. I'd typed out a fairly lengthy reply but forgot to hit submit...

Ran through the diags, got a weird one, on one of the tests one's supposed to get 0V at idle to Pin 105 on the ECM, and battery voltage at 2000RPM, and it looks like the diagnostic procedure has one go through more tests if one gets 0V at 2000RPM. Unfortunately for me I was getting battery voltage at idle.

Did some further disassembling and found the little 1/4" ID hose between the EGR valve and the component right above it was very, VERY bad. Like that gooey, barely not a liquid kind of bad. Replaced that, replaced several other 3/16" hoses that were also showing signs of being worn.

Cleared codes and road-tested. no new codes this time. Idle still isn't perfect but it is better. Tach still doesn't work properly, and the idle speed screw on the computer doesn't seem to be doing anything either.

Will have to put some miles on it this weekend to see how it does, and still need to bleed the clutch hydraulics.


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## TWX (Jan 29, 2010)

Wife helped me bleed the clutch. It's still grabby, but the pedal range is a little better and more predictable. Still might need a clutch replacement, we'll see.

Since replacing that 1/4" ID hose haven't gotten a CEL. Did probably 20 miles of mixed city and freeway mileage, so far so good. Stumbled across my old tach/dwell meter, checked RPM on the engine, it's actually idling around 850RPM. Doesn't sound like that to me, but I think I'm hearing various rattles that I'm not used to so I was thinking it was worse than it is.

Did some poor-man's body work, Pushed the core support back out which pulled the fender back in, fixed what needed it (didn't damage paint enough to bother needing to touch-up) and swapped bumpers and some other parts between the two trucks.

Started trying to straighten the bent bumper enough to put it on the other truck, didn't get very far on that. It'd a bit difficult to position it on the 20 ton press, may have to rethink how I go about straightening it, or see if I can find a cheapo bumper that's in better shape than this one to put on the other truck.

Tach in the truck still doesn't work, tonight's roadtrip showed me that much, but otherwise it's feeling very good. Will probably drive it to work over these next few days to see how it does, and possibly stop by a couple of wrecking yards to see if I can find a dashmat and a couple of good sun visors, and maybe a center console out of a '98+ Frontier to swap in to get some half-decent cupholders.


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