xsohaib

I have a HUGE problem, I had the valve stem seals chnaged and I asked the mechanic to port and polish the head also. After 8 days at the the mechanic, he finally called today and told me to pick up the car. When I went to pick up the car intially had slight white smoke on ful throttle, and then when I left the lot I noticed that the car was as if being robbed of power, then eventually it died when I let go of the gas as if the throttle positioning sensor was gone. Long story short, I have a sever black smoke on idle and on throttle. and excessive fuel smell from the exhaust. the idle is rough and it seems to be robbed of power. I don;t know what it could be

Please help

Also he has been tinckering with the timing for the past two days?

Cheers
Sohaib

Pheonix

Welp.
Sounds to me like the ignition / cam timing is way off causing a lack of power & poor combustion.
I would put a timing light on it ASAP. (Jump E1 & TE1 in the diagnostic port) to check ignition timing. THEN I would pull the valve covers off & check the base cam timing. (With the crabkshaft @ top dead center - 0* the two dots on the driver's side of the intermesh gears should touch each other.)


For lack of a better way to explain it, this is a 1mz-fe. See the two dots align.


The difference is the 3vz-fe intermesh gears are in the middle:

& the dots are on the opposite side (driver's side)







3vz-fe's (Your engine) are resistant to detonation, but if you simply go way too far with the ignition timing, it's going to be like any other engine. You'll burn a hole in the head gasket<s>.

xsohaib

Thank you so much, a friend of mine also said that when you port and polish the head you have to put the car on a dyno to "totally retune it", is that true? BTW both he and I are medical students and hence our mechanical skills are rather limited.

Cheers
Thanks again

Sohaib

xsohaib

Do the rear banks (the rear three cylinder) intermesh gears also need to be worked on? i.e. would I have to align the intermesh gears in the rear also or is it only in the front part as shown in the picture?


Sohaib

Pheonix

No porting & polishing a head doesn't need any tuning by itself. Stock ECU's will realize it. Now on a side note, you can normally gain 10-15hp on toyota's conservative engines by retuning fuel & ignition & have that, if not a little more when done on top of other mods.
But you don't have to do it & it won't cause a problem by not.
Unfortunately, the distributor (Which sets base timing) is driven off the itnake camshaft of the rear bank. So ya, it's best to check it also.
I would check ignition timing & check the front bank cam timing (Because it's muhc easier). if either one is off, then ya - rip that upper itnake & rear valve cover off (Sorry!)

Doesn't mean I'm right, but I think cam & ignition timing would be the best place to start in this case.







The good news is that if you have to take the upper intake manifold off, you can spend an hour cleaning it by hand. =)








They dirty up & normally loose 5-10hp compaired to a clean system.

xsohaib

Thanks again pheonix,

Another question is that you mentioned that although the engine is detonation resistant, it may in fact damage the head gasket under current conditions. But do you think it can be driven about 3-4 miles, because that is how far my mechanic is. I think my biggest mistake here was that I should have waited to get back to the states to get this job done (I was gonna ship out my car yesterday) and instead I decided to do it here in the carribbean. Oh well! BTW, I must say that I am highly obliged for your help!

Sohaib

Pheonix

No need to thank people. It's cool. Ya you can do whatever you want. I would keep my eye on the coolant gauge. If it passes 1/2 way in a hurry speed up to 40-50 mph put it in idle & let it coast the rest of the way.

xsohaib

At around midnight, I decided that I should have a look at the intake, so I open the hood and when I touched the intake (plastic part that houses the air filter), it felt like the two clips facing the engine side were not clipped. So I decided to take a look inside, and guess what I see, the air filter had been "installed" (using the word installed quite loosely here), upside down and a big chunk of the air filter was stuck in the intake piping. So I unscrewed the bolts/clips that hold the intake pipe and pryed out the paper filter. It was completely blocking the opening of the intake. Anyways, this afternoon I went to the local NAPA and picked up an air filter and installed it in -----> whoala, started up, smooth idle and no smoke at all. Then I decided to take it for a spin, and treated the car to an Italian tune up job (WOT), no problems, and infact I can "FEEL" the increase in power from the port and polish (or maybe it is a placebo affect?

Anywho, the car is fixed

Cheers

Sohaib