I NEED HELP BAD, High RPM miss

So hi guys. (I know this is a long post, but for you gear heads it's a nice challenge, that said I appreciate you reading all this, I am so depressed and stressed out of my Mind over this!)

I'm still chasing this miss. I have gotten real serious now because for months it had been very distinctive and drive-able. distinctive meaning it was running absolutely perfect under 3200 RPMs so it hadnt been a issue that kept me from using the truck. I have been working on it and I took apart the Manifold to test the knock sensors, took the coils off and tested them as well as wires and plugs replaced the plugs. Put it all back together and now it runs like absolute crap at all rpms including idle.

So, here is a description of problem, codes from OBD2 scanner, list of things I've done as well as live data freeze frames thru the RPM range until it hits the hard miss... PLEASE HELP

2002 3.4l tacoma

Symptoms: High rpm miss at excact RPM 90% of time but would move around some as I manipulated parts, but always ended up back at 3200.

Ocassionally would move into the 2400 rpm bracket, but like said went back to 3200.

Sudden change after mecanical work to now running terrible and throwing missfire codes for cylinders 1,2,4,5,6... (Why not 3?) Also code for "Random Multiple Missfire"

I have done the following.

Checked spark (inline spark tester) (OK)
Checked coils resistance they were in bottom of range but met spec just barely
Checked fuel pressure (OK)
replaced MAF sensor
Replaced Igniter (Ignition Control Module)
OHMS test Crank Position Sensor
Ohms Test camshaft position sensor

Put at TDC and verified cam pulley tabs lined up with notch in rear cam pulley cover (Timing marks on belt saying "Right Cam - Left Cam" did not line up with paint marks when at TDC, that said does that really matter as long as the tabs on the pulleys lined up with the notches as spec? the belt was replaced once way back ago buy a mechanic)

Pulled lower intake and tested Knock sensors (did find bad wiring at plugs but still tested "OK" then fixed that and then re-tested buy checking base voltage then banging on them and watching voltage spike, confirmed "OK"

Cleaned and tested fuel injectors all were actuated manually and confirmed even spray.. (Did notice two injectors wet at base after re-assembly, figured bad upper o-ring went bad from being messed with, so will have to fix that)

checked fuel pressure at fuel rail and it is at 44 PSI per spec. Was not able to test pressure at the high RPM miss cause I tested this after it started running crappy. (But would a bad fuel pump cause a high RPM miss? Is that possible, I would think it would miss in all ranges with fuel pump going bad?)

Ohms tested TPS sensor and it tested good but replaced anyway cause I suspected it. The live data shows with engine off ignition on the WOT reading is at 75%... Should the TPS be showing 100% at WOT? Maybe needs adjustment?

Inspected all vacuum hoses, do not have a vacuum test gauge kit, it's on it's way from Amazon. Once again I dont think this is it, it seems to have good vacuum, you pull a hose from intake and it kills it, put it back on it runs.


Checked all grounds

Checked alternator

changed fuel filter

tested injector plugs and harness

Did compression test. The test conditions were no throttle, just crank of engine period and read compression, all within 5% of each other. No leak down tester yet. It's in mail to me (I'm in Alaska) so for now have to wait for that, I know I probably should have checked compression at WOT right? but it met specs.

So, at this point I dont know where to go next. I'm really lost here. It was in the Dealer for 5 weeks and they couldnt figure it out. Then in the end in week 5 they said they think the water pump leaked on timing belt and cause it to jump a caug/tooth but weren't positive. I took the truck back because I was of the impression that if the belt had jumped time it would run like crap all the time, then I removed covers and put at TDC and saw that even though the belt lines didn't line up the cam pulley tabs did line up and I'm assuming the last mechanic just put the belt on without lining up the marks on the belt. But what difference would that make? All that said, the water pump is most def leaking. It's obvious and has been a good long while.

I dont know guy's I'm so lost and depressed, I swear. I'm thinking I'll re set timing just cause I dont know what else to do even though I think it's right. Also, I've heard if you dont torque that crank pulley bolt to proper torque (Like 250 ft/lbs) it can work loose and cause the crank sprocket to wobble and send incorrect info to the ECM from the CPS and cause a high RPM miss and then as it gets worse become a problem continuios not just at high RPM, possible it was that and when I was cranking it to TDC manually I loosened it up some more so it's now running like crap? Hell I dont know I'm grasping here.

Here is the Code info and Live date. See the Frames per RPM ranges...

2002 Toyota Tacoma 3.4

I/M Monitors

Since DTCs Cleared

Misfire Monitor ok
Fuel System Mon ok
Comp Component ok
Catalyst Mon inc
Htd Catalyst n/a
Evap System Mon inc
Sec Air System n/a
A/C Refrig Mon n/a
EGR/VVT Sys Mon n/a

=====================

DTCs (Codes)

P0300 ENG $10

Random - Multiple Misfire Detected

HISTORY



---------------------

P0301 ENG $10

Cylinder 1 Misfire Detected

HISTORY


---------------------

P0302 ENG $10

Cylinder 2 Misfire Detected

H
---------------------

P0304 ENG $10

Cylinder 4 Misfire Detected

HISTORY



---------------------

P0305 ENG $10

Cylinder 5 Misfire Detected

HISTORY

---------------------

P0306 ENG $10

Cylinder 6 Misfire Detected

HISTORY

---------------------



----------------------



=====================

Record Data @ IDLE

FRAME: -1 TM: -3.4

MIL STATUS On
ABSLT TPS(%) 9.4
ENG SPEED(RPM) 910
CALC LOAD(%) 23.5
MAF(LB/M) 1.02
COOLANT(°F) 158
IAT(°F) 61
IGN ADV(°) 13.0
ST FTRM1(%) 0.0
LT FTRM1(%) 0.0
VEH SPEED(MPH) 0
FUEL SYS 1 OPEN2
FUEL SYS 2 N/A
EQ RATIO11 1.000
OBD2 STAT CA

---------------------

@ light acceleration in neutral

FRAME: 5 TM: 16.0

MIL STATUS On
ABSLT TPS(%) 11.4
ENG SPEED(RPM) 1513
CALC LOAD(%) 23.5
MAF(LB/M) 1.72
COOLANT(°F) 162
IAT(°F) 61
IGN ADV(°) 24.5
ST FTRM1(%) 0.0
LT FTRM1(%) 0.0
VEH SPEED(MPH) 0
FUEL SYS 1 OPEN2
FUEL SYS 2 N/A
EQ RATIO11 1.000
OBD2 STAT CA

---------------------

@ medium acceleration in neutral

FRAME: 6 TM: 19.2

MIL STATUS On
ABSLT TPS(%) 13.3
ENG SPEED(RPM) 2108
CALC LOAD(%) 23.9
MAF(LB/M) 2.39
COOLANT(°F) 163
IAT(°F) 61
IGN ADV(°) 31.0
ST FTRM1(%) 0.0
LT FTRM1(%) 0.0
VEH SPEED(MPH) 0
FUEL SYS 1 OPEN2
FUEL SYS 2 N/A
EQ RATIO11 1.000
OBD2 STAT CA

---------------------

@ Dead miss, cannot gain more RPM, complete MISS, Blinking
CEL and hard hard miss...

FRAME: 8 TM: 25.6

MIL STATUS On
ABSLT TPS(%) 16.1
ENG SPEED(RPM) 3071
CALC LOAD(%) 27.8
MAF(LB/M) 3.79
COOLANT(°F) 163
IAT(°F) 59
IGN ADV(°) 29.5
ST FTRM1(%) 0.0
LT FTRM1(%) 0.0
VEH SPEED(MPH) 0
FUEL SYS 1 OPEN2
FUEL SYS 2 N/A
O2S12(V) 0.000
O2S11(V) 3.298
EQ RATIO11 1.000
OBD2 STAT CA

---------------------
Now reducing RPMS from Hard miss at higher RPM...

FRAME: 9 TM: 28.8

MIL STATUS On
ABSLT TPS(%) 13.7
ENG SPEED(RPM) 2491
CALC LOAD(%) 20.0
MAF(LB/M) 2.18
COOLANT(°F) 165
IAT(°F) 59
IGN ADV(°) 30.0
ST FTRM1(%) 0.0
LT FTRM1(%) 0.0
VEH SPEED(MPH) 0
FUEL SYS 1 OPEN2
FUEL SYS 2 N/A
O2S12(V) 0.000
O2S11(V) 3.298
EQ RATIO11 1.000
OBD2 STAT CA

---------------------

 

Dont feel bad man, I have been chasing my code for 8 months now. $2,500 later I still havent solved it. I'm misfiring in #2 and#5, when hooked up computer and at high rpm, comp shows NO MISFIRES. BUt still throws code. i have replaced, wiring harness, spark plugs, coils, timing belt, cat convert, crankshaft pulley tightened, engine practically re-wired. And i cant figure it out.

 

I read and thought. Is 30 degrees ignition advance reasonable? Just an observation as I cannot measure mine and determine what mine is. Good luck. Thinking of your problem. Someone who knows answer this question.

 

I'm not a mechanic but from reading your post I would, and it's just a suggestion as it's what I would do...

Find another mechanic, not the dealer...
Replace that leaking water pump.
Replace the timing belt and put it on right.
Replace the coils, being barely within spec on the low range means they are going out of spec as they heat up. This is most likely your problem.
Replace the plugs and wires.

See if that does the trick.

I would not touch the distributor. Unless it's loose and slipping, there's no reason for it to change

 

According to the '96 service manual i have you should check the following things when those codes show up.
Ignition System
Injectors
Fuel Line Pressure
EGR
Compression Pressure
Valve clearance not to specification
Valve Timing
Mass air flow sensor
Engine coolant temperature sensor.

I see you have checked most of that. If you want to PM me with your email i could send you my .pdf repair manual. Might take you a while to get it, Its 95MB. You would never get it unless you have a fast connection.
Maybe buy some of this stuff and hit every electric connection you can find.
http://www.walmart.com/ip/CNC-QD-Electronic-Cleaner-11-oz/16817418

 

Send some of that repair manual action my way if you don't mind?

 

OP,
30 degrees of advance is normal. That's what I see when cruising.
Your idle rpms seem high. My 2.7 hot idle is around 650.

You do NOT have a distributor.

Have you ruled out bad gas? Plugged exhaust? plugged cat?

What was your compression ( in PSI ) ?

I think, that as far as the timing marks are concerned, so long as both cams and crank show TDC, and the #1 piston is at the top, that should be OK. (however, you should know, I have no personal experience with this motor)

 

I’m hoping to resurrect this thread as I have the exact same problem, was there ever any solution to this from the OP? Or has anyone else experienced this issue? Please help!

 

OP has not been seen on TW since 2013. This thread was his last post.Start a new thread. Good luck.
And
Welcome aboard new member.

 

I recommend you start your own thread to avoid any confusion.

 

you are not going to like my sugestion... take it all the way apart down to the cam belt gear on the crankshaft and pull the gear off and look at it carefully. It is not supposed to move at all on the crankshaft and make sure that all of the teeth on it are on it or bent. Sometimes the goove in the gear gets worn and the gear shifts slightly during running and it will give you the sypmtoms you are describing. Yeah pain in the ass just to do a check. When you get the belt on and timed, rotate the crank 2 times by hand and verify the timing marks again.

 

I had this problem once and it was related to the coil packs there was no way to test them they tested good but they would fail at a certain RPM range intermittently it took me a year to figure it out by replacing all the coil packs,
I never got a code and the dealer couldn't figure out what it was either.

So I replaced the spark plugs and the coils and the spark plug cables and that solved all my problem.

Knock sensors if they're not OEM might cause a problem to

 

I had a similar symptom. High RPM but only noticable under heavy load. Turns out I had corrosion on the secondary side of my ignition coils from ingress of moisture into thr spark plug wire to ignition coil boot. The high resistance was melting my spark plugs to a nub after 10k miles.

I replaced the coils (still tested good), plug wires (tested good) and spark plugs & it remedied the problem.

 

Hey Folks!
New member here, wanted to say thanks!

I had the same problem, multiple misfires, changed plugs and wires.

The problem was the Crank Position Sensor and wouldn’t throw a code. It would only show a problem when it was actually misfiring at 3200 RPM.

Replaced the CPS and we’re good to go!

Thanks again,
DenimDan
1999 Tacoma V6, 250k Miles