RunnerUp

Hey guys, just posting this for a friend over on TTORA. He has been having this problem for a week or two now and has replaced his plugs/wires and fuel filter to no avail. Here is a direct quote from his thread on TTORA-

"Alrighty, a few times in the past week, as I am accelerating, once I hit high RPMs the Engine sputters big time. I don't have a tach so I can't say exactly when, but with 3.91 gears, 31's, 3.4L and a 5 speed, It starts at 23ish mph in first gear (25ish should be redline per my calculations)- and 44 mph in 2nd gear, and sometime around 65 in 3rd gear. I rarely venture into that rev range, but when I have in the past, it's been fine.

It is on my 99 Tacoma, with 125k miles. Just had the timing belt and pumps changed ~1k miles ago. Been through at least 2 different tanks of gas while this problem has occured, which should rule possibility of bad gas out.

It sounds and feels as though it is bouncing off the rev limiter, though I know I'm not. I've read of others having sputtering problems, though all I've seen have occurred at idle/ low RPMs. The solutions I've seen for them have been new plug wires and/ or fuel filter. Both of which are original on my truck, and I've been wanting to replace. Plugs are relatively new, though I will try to check them tomorrow. MAF, throttle body, intake and Air Filter are all cleaned religiously. The only aftermarket part that could even possibly be related is a Flowmaster 40 muffler, though its been on for probably 10k miles.

Truck is throwing no CEL, or having any other symptoms except possibly my clutch going bad. With even the slightest pressure on the clutch pedal, a whirring noise occurs. Maybe it is going bad and the higher torque at the high RPMs is causing it to slip and allow the engine to redline at a lower mph? Any help or ideas are appreciated.

EDIT: Oh yea, I will try to rev the engine by hand in neutral (duh) tomorrow to see if I can rule out the clutch/ tranny. It's nearly 1230 in the morning here and the neighbors wouldnt be happy if I tried now.


CLIFFS:
-High RPMs truck seems to bounce prematurely off rev limiter.
-Nothing else notably wrong except possibly clutch (see last paragraph)

Thanks guys,

-Chris"

RunnerUp

Alrighty, I changed the fuel filter, and nothing changed. Next I will go get some plug wires. PepBoys said something like 41 bucks for 50,000 mile warranty wires, and 50 for lifetime warranty. For S's and G's I pulled one of the plugs from each cylinder bank to see what they looked like. They have about 20k miles on em, and I seafoamed the engine through the PCV valve about 500 miles ago.

RunnerUp

I'm going to be ordering new plug wires and plugs probably today, and change them out hopefully sometime this week if I get a chance between work and the school starting. Thanks to DentedTaco (i think that's right) I was able to swap out my gauge cluster, and have found that the sputtering occurs right after I hit 4,250 RPMs, both in neutral and in gear, ruling out the possibility of clutch slippage. I'll keep updating until this is fixed, for other's future reference, and to hear anybody elses suggestions.

My neighbor tossed the idea out there that possibly during my last wheeling trip something kicked up and hit the fuel line, causing it to kink and not allow enough fuel at higher RPMs. I'm gonna just eyeball that possibility as well when I get a chance.


I just finished installing all new plugs, as well replaced the wires. The engine sounded better through the exhaust (not that it ever sounded bad) and it was a bit more responsive through the throttle as well. but it is still sputtering out at the same RPM :mad:

If I took video of it happening with sound, do you think it would help? I guess it wouldn't hurt, so I'll probably be back in a little while with an A/V clip. As Scoot said, I still haven't done anything with the Cat- Is there anyway I can rule that out, short of cutting it out?

Open to more ideas again, and I'll be back with some video and sound.

Lets see if this works

From inside the cab
http://s151.photobucket.com/albums/s...t=CIMG0006.flv

Camera placed just behind truck, on the ground.
http://s151.photobucket.com/albums/s...t=CIMG0007.flv

RunnerUp

oh, and here is the original thread over on TTORA for reference

http://ttora.com/forum/showthread.ph...36#post1340636

GatorTaco

97ltd4x4

If its hitting off of the rev limiter,clutch is on its way out......

GatorTaco

it's not the rev limiter, It's starting right around 4250 RPMs and it does it both in gear, and in Neutral. My first thought was also clutch slippage when the torque got higher also, but it's not the case. Additionally, from a stand still the clutch will lock up under full throttle and I can still spin both rear tires (LockRight in the rear axle- and no, I don't do that often )

RunnerUp

coughbullcough

GatorTaco

lol ya gotta admit it's fun though. V6 + 5speed + full time locker =

Yota Runner

how do the boots that go over the plugs look? If they are cracked at all it will cause a miss....more noticably at highs rpm's! The boots should have not cracks at all. When I baught my rig it was doing this and low and behold I had a boot with cracks in it...the way you can tell is to roll the end of the boots between you fingers with a little pressure to find the cracks

j4eric

dont they have a recall on this Tacoma model? about rusting?

GatorTaco

yea but the frame looks like I just drove it off the lot.


I don't recall the boots being cracked... though I will definitely go look right now. They are noticeably more dirty (like a brown rust-ish) color, could that be a sign? I think I may even have a pic...

got a couple...







I'm also gonna guess that the rust stuff in the tubes isn't good. Any word on that?

Yota Runner

its hard to tell from the pics...make sure you squeze them a little when you roll them between your fingers, as far as the brownish color it looks like a little moisture is getting in there. I am not sure its to big of deal but I'm not totaly sure on that. let is know what you find. it only took one of mine with little splits on the end of the boot to make it run like crap at high rpm.

wjwerdna

Wow... this is word for word exactly MY problem as well... started as a miss around 4200-4300, now at 4000, every time.

I've been through several tanks of gas, and much of the same other things as well. My plugs/wires, and fuel filter were all replaced ~10k ago or so?

It does this sitting in park and neutral, and in all gears

VERY interested in seeing if you figure it out

I also have a squeaking/chirping engine, but that is a different problem (waterpump/belts?)

GatorTaco

all the boots look good. I'm really starting to think it's timing belt related, since It was just replaced, and this problem began immediately following. I'm taking it back to the guy who did the T-Belt as soon as I get back down to that side of the state. I'm currently battling a bad bearing and seal in my rear axle, so I'll be doing all of those this week

Ill keep this updated WJWERDNA, though it might take a fair amount of time.

-Chris

wjwerdna

cool, thanks... mine is still doing the same, haven't really done much... in process of seeing if injector cleaner in tank does anything, I'm kind of at a loss of what to do...

(oh, and my chirping was just a bad belt... probably overtightened, and got out of shape (points were more pointed?) fixed temporarily with taking edge off with file)

dairyjato

i had a 86 toy p/u that did kind of the same and it was the begining of a cracked head. all that rust dont look right either. how does ur oil look?

GatorTaco

Yea, I put that in my last tank as well, and it hasn't done anything.

noooooo. don't say that about my truck! It runs perfectly strong at all RPMs until right at 4250. Good power and torque under load from a stand still, etc. My gas mileage isn't anything to brag about, but should be a little better IMO. (around 19 highway with 30" street tires and 3" lift- no armor to weight it down )

EDIT: Ooops- I forgot to say- The oil isn't bad. Maybe a little brown, but nothing unusual, especially for having >2000 miles on it.

GatorTaco

alrighty, so I found the problem. There is a pulley in front of the engine, attaching all the accessory belts, and a 19mm bolt holding it on. Apparently the bolt wasn't tightened correctly by the genius who did my timing belt. (not me) I found this out when the other night my power steering went out and my battery light came on, signaling an error in the alternator. I immediately got home and popped the hood- started the engine, and heard a horrible tapping coming from the pulley, which was also wobbling like crazy. I just tightened the pulley back down and all the problems went away lol.

Thanks to everybody who gave me ideas to help! I REALLY appreciate it!

-Chris

wjwerdna

WOW... just looked up this thread to post my response.... I finally fixed my 4Runner in December. SAME THING!!!!!!!!

I replaced soooo much stuff trying to figure it out. Drove my truck like this for about a year, turns out it was the loose pulley at the bottom of the timing belt. At high rpms, it would move enough on the shaft that timing could not be measured, and thus wouldn't go past 4000 rpm.

The shaft, key, and pulley were a little nicked up, and edge of timing belt was worn from stuff moving, but new timing belt, accessory belts (while there), and water pump later, all is good.