thumpity

I've been poking around on these boards for a few years now, It's about time I post. I've had a CEL on for a while now. A mechanic I trust told me that the evap system is playing up. The charcoal canister needs replaced and that's expensive. Apparently I can wait to fix that: I'll lose a little bit of power and notice decreased mileage. A nearby dealer quoted about $900 to replace the charcoal canister. Not really a big deal, there's no emissions testing out where we live. I don't have $900 just floating around. But, driving around with a CEL on isn't the best idea. Good mechanic suggested I buy a cheap ODB2 code reader and keep an eye out for new codes.

Searched on amazon found a cheap ($20) code reader, plugged it in and was off to the races. I now have a lot of data which I don't really understand, and don't quite know what to do with.

Before finding the mechanic I trust I had been taking my truck to another not completely honest mechanic who seems to have been replacing perfectly good parts with bottom of the line parts and not so top notch work. We caught him out lying to us about thousands of dollars of urgent work and have never been back. One of the many jobs he did for us is to replace the timing chain.

My new scan tool reports that the timing is off, constantly, by about +10-12°. The truck's felt different ever since he (bad mechanic) "fixed" the timing belt. When I asked him about the truck running just very slightly rough he had assured me its perfect and not to worry.

The dealer I spoke to figured bad mechanic installed the chain incorrectly and is out by a few teeth on one of the cams. I think he said cams, but I'm not as mechanically inclined as most of the folks around here seem to be. The dealer wants $450-500 to replace the timing chain. I don't really have $500 but I love my truck.

What should I do? What would you do?

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• 1999 Tacoma TRD Off-Road
• saved up all my life bought my dream truck
• 1000's of miles way way out in the middle of nowhere
• multiple photos of wild horses running beside the truck
• best wife ever knows how much I love my truck and takes turns driving while the baby rides shotgun

rworegon

What CEL code(s) exactly are you getting?
What is the rig? Year/model etc
What engine?

Welcome to YT!

thumpity

Hi rworegon, Thanks for writing back. My truck is a 1999 Tacoma 3.4L FVZ-FE V6 TRD Off-Road. The CEL codes are P0441, P0446, and P0450. I don't think I have to be too worried about those. I replaced the gas cap, it always makes a sucking sound when I unscrew the cap. We're pretty sure it's just a worn out charcoal canister generating those.

More concerning is that the code reader (x-series code reader + dash command app) shows the timing at +10° to +12° higher than it should be. I had the timing chain replaced a year or so ago. The truck's felt ever so slightly rough since then. I've only had the code reader for a week or so but it's been very consistent in it's reporting of the timing being off and gives a numeric read out of what i'd been feeling.

wyoming9

iTrader: (1)

I can understand people do make mistakes and take no responsibility for doing poor work.

If you feel you have really been ripped off why not go back and try and get things fixed first. Yes I know it can be hard if you are really clueless but you should be able to find some one to help.

There is always two and sometimes three sides or more to every story.

Then if this business is really that bad share their business name to help the next clueless victim .People wonder why they no longer have business after so many disgruntled customers .

While other shops are seeking to hire more people.

I can only add try and learn as much as possible about the basics of how things work

rworegon

Ah, it's a 5vz-fe with a timing belt, not a timing chain.

How are you determining the timing is off the 10-12 deg? Just looking at what the reader is showing? What is the reader showing for timing at idle with engine at full operating temperature? What Is the idle RPM at time of answering previous question?

A vacuum leak in a vac line, throttle body gasket, the intake tube, etc. could be causing the roughness.

Checking the timing belt for proper alignment And engine timing is quite easy to verify.

Remove the negative battery cable, turn the crank clockwise until the notch is at the 0deg TDC mark. Now, pull back the upper radiator hose clamp and remove the bolts on the upper timing cover to slip it back so you can see the front of the cams. Is the scribed mark on each cam lined up with the notch on the backing plate? If so, great the engine valve timing is set.

If the cam marks seem off 180 deg, rotate the crank one more revolution clockwise back to the 0deg TDC mark and recheck cam alignment marks.

J2F42C

+1 with rworegon. To check the timing is as easy as lining up the harmonic dampener to 0, then get some locking Vise Grips to pinch the upper hose clamp. Remove the upper cover and check the cam marks against the backing plate.

After my friend and I changed out his timing belt years ago his driver side valves were noisy but the t100 ran fine and no CEL. So we checked the cam marks and the drivers side was advanced one tooth ahead of where it needed to be. Loosened the belt by removing idler#1, rotated the cam, put it all back together and everything was A-Ok afterwards.

rworegon

From my 1995 5vz-fe Factory Service Manual (FSM):

Ignition Advance: Ignition Timing of Cylinder 1: 12.5 ~ 22 deg BTDC idling @700 - 750 rpm (this is the value your scanner is reading) Page: EG-246

Ignition Timing with Terminal TE1 and E1 connected at the Diagnostic Box attached to driver side of upper plenum: 8 - 12 deg BTDC @ idle 700 +/- 50 rpm. Page: EG-116
Put a jumper across TE1 and E1 and then see what your scanner reads.

The specifications for your '99 5vz-fe are likely very similar, if not exactly the same.

rworegon

Here is what the cams should look like when properly aligned at TDC with the crank at TDC:
https://flic.kr/p/o56zjF

Photo credit to member mazaa.

TheDurk

Seems to me there is some confusion here between VALVE timing and IGNITION timing, two very different animals. VALVE timing is mechanically controlled by the timing belt, relying on the alignment of the crank and cam pulleys to the toothed belt at TDC on #1. Ignition timing is electronically controlled by the ECU, relying on the electrical impulses from the cam and crank sensors, plus a whole lot of other inputs.

I am skeptical of a scan tool being able to read 12° out on ignition timing, as the timing by the ECU is continuously varying. If you've ever hooked up a light and looked at your ignition timing, it moves forward and back rapidly between the values posted above. So my question is, 12° out from what? I don't think a scan tool can check valve timing at all.

Of more concern is rough running after TB work. Far too many times this is not because the TB is out of time on the sprockets (checking this is correctly explained above). What has happened to others is mechs unfamiliar with the 5VZ-FE fail to properly tighten the crank bolt to the whopping 217 ft-lbs torque spec and the sprocket gets loose on the crank shaft. This allows the key to shear and the sprocket to revolve on the crank nose, throwing off BOTH valve and ignition timing. NOTE that checking the cam sprockets against the shifted crank sprocket will still show all as perfectly aligned, when it isn't.

Eventually, the sprocket and harmonic balancer will work themselves loose and the HB will grenade and the keyway slot in the crankshaft will wallow and ruin the crankshaft, effectively totalling the engine.

I'm not saying this HAS happened, but with this symptom set I would sure as ˟˟˟˟˟ rule this out by checking crankbolt torque and verifying TDC as shown by the sprocket the old fashioned way, with a pencil in the #1 cylinder hole. You might save your engine.