2ZZGE OVERREVVED TO 10K

[Raja Talha]

Hey! So this Saturday I had a run with a 4age Toyota Ceres, was ahead by two cars' length in third gear (145kph) and mistakenly shifted to second gear instead of fourth gear , RPM went beyond 9k. Instantly I shifted to neutral and took it to the side. Now gear wouldn't shift while clutch pedal felt normal and engine was vibrating as if one ignition coil was not working. All the bad imagination comes rushing in since 2zzge isn't known to handle overrevs so well due to it's weak oil pump and also that it's an interference engine. So I put the car in neutral and ask some friends to push start the car fortunately the transmission shifted to second gear, 100 meters ahead car started to *****; similar symptom of a failed ignition coil, so we decided to tow it. Now at that time vibration had gone but recurred after a while. Next day went to a shop and asked my local mechanical stig (jk) to check the transmission, fortunately it was just a clutch disc (old but was fine) ,pressure plate and throw out bearing, shifting problem was gone but so did vibrations along with apparent misfiring/ignition problem.

Now I can't make up anything out of these series of unfortunate events i.e. how can vibration & apparent ignition problem (assuming because car wasn't acceleration and was jerky) be gone after changing clutch disc and throw out bearing. Can anyone explain this? Also if anyone can suggest an easy way to check if I have some slightly bent valves or something. I tried Lift once after the incident and it feels normal. 

Edited February 17, 2017 by Raja Talha
missed an information

[campbeam]

On 15/2/2017 at 2:51 AM, Raja Talha said:

Also if anyone can suggest an easy way to check if I have some slightly bent valves or something.

Start with a compression test on each cylinder. If you have compression, the valves should most likely be OK. Presumably if the valves are bent then they will not close.

Another test would be to rotate the camshaft/s by hand and check the valve clearance.

[trentmeyer23]

Was it actually misfiring or was it bogging down?

[Raja Talha]

On 16/02/2017 at 9:25 AM, campbeam said:

Start with a compression test on each cylinder. If you have compression, the valves should most likely be OK. Presumably if the valves are bent then they will not close.

Another test would be to rotate the camshaft/s by hand and check the valve clearance.

So what i've read is 2zzge has to have minimum 205psi. Also is there anyway to check if it's an exhaust valve or intake valve without opening the engine head. I'll do that camshaft check.

[Raja Talha]

21 hours ago, trentmeyer23 said:

Was it actually misfiring or was it bogging down?

Well, yes it bogs down at low throttle but at WOT it drives totally normal but bogging issue doesn't happen all the time, like today I was facing the bogging down issue at low throttle so I drove for a km or two and turned off the car, on restarting it the issue had gone and didn't recur in my 20km drive. Similar thing happened to me yesterday.

[trentmeyer23]

On Friday, February 17, 2017 at 2:53 PM, Raja Talha said:

So what i've read is 2zzge has to have minimum 205psi. Also is there anyway to check if it's an exhaust valve or intake valve without opening the engine head. I'll do that camshaft check.

Yes. It is called a cylinder leakdown test.

[Raja Talha]

So finally good news 2ZZ AE80  was lately facing same bogging down issue at low throttle and was emitting black smoke despite lowering the fuel pressure from 50 to 45 psi. Last week I changed the battery, tucked some wiring near fuse box to bring an intake pipe from underneath the fuse box (FOR COLD AIR) and repaired the exhaust as it had a leak. 

Next thing is there is no black smoke, no hesitation at low revs and mileage has gone up. Any justification for this??

[Raja Talha]

Latest update: Hesitation at low rpm (constant throttle) has again started to occur, when car is below 2.5k rpm and is kept at constant throttle it starts hesitation. No issue at wide open throttle. Also it doesn't happen in first 5 minutes when the car is started. Symptoms:

1. Black smoke

2. Hesitation (at low rpm and constant throttle)

3. Misfire (at times)

[trentmeyer23]

Have you had any testing/diagnostics conducted?

Have you pulled the plugs?

Have you checked the timing chain hasn't skipped a tooth?

[Raja Talha]

On 28/04/2017 at 3:45 PM, trentmeyer23 said:

Have you had any testing/diagnostics conducted?

Have you pulled the plugs?

Have you checked the timing chain hasn't skipped a tooth?

Yes, I had diagnostic conducted and not a single value was off but that was when I changed the battery and every thing was smooth for about a week.

Plugs were pulled, they are Denso VK20 didn't appear bad. Do you reckon if a tooth is skipped the car will run (especially for 5 to 10 min until the engine has warmed up)?

[trentmeyer23]

The car would still run if one or two teeth were jumped. I would be pulling covers off and checking.

I would also have a leak down test conducted. Better to rule out any possible internal damage. 

It may be something completely random as well, but the over rev is the most concerning thing to me.

[Raja Talha]

Just in case someone is facing the same issue, try this: Final update, issue now has been resolved. What's interesting is how it got solved. 

Me and my brother took it to the diagnostics guy who also did the wiring for me and asked him to service it for us. He cleaned the throttle body which didn't solve the problem. He removed the intake pipe and reassembled which also didn't solve the problem, finally he asked us to try the other MAFs he had in stock which we did but still were facing the same issue. Finally out of frustration we asked him to just wrap it up as we were getting no where, he put the intake setup together and bam the hesitation is gone and no black smoke. We asked him to just tie things up so they don't move an inch (afraid of facing same issues). But never faced that problem ever since. Lastly I gotta say 2ZZGE is a pretty solid engine unlike what's commonly said. other than this personal experience, an ae92 guy misshifted leading to overrev his engine is fine also, plus other guys who have swapped them say its pretty rugged.