It Need help on a 4age... Options

[biglipzit]

Ok guys it isnt a 6th gen but a toyota levin with a 4age engine that i am working on... It has some serious problems which I am baffled by. Sometimes it works and sometimes it doesnt... What I mean is sometimes it runs perfect and other times it picks up slowly and has almost no power. The vvti kicks in at 4000rpm like normal all the way up to the 8300rpm rev limiter but then engine light comes on after a while and it wont deliver as much power or rev as fast as it use to. I changed injectors and fuel pump thinking it might be a fuel pressure problem and still nothing. Change fuel pressure regulator and it isnt that. Tried a different ecu and it isnt that either. It wouldnt start the other day after a period of running with the engine light on and i had to disconnect the battery and reset the ecu before it would spark again and it started again and ran perfectly then after a stop to the gas station the engine light was on again and it wouldnt deliver... I thought it could be compression rings and valve seals going but then that wouldnt explain why it only happens sometimes. If it was compression then it wouldnt work sometimes and not work others. I am thinking that maybe the O2 sensor is bad and messing up the ecu and causing the loss of power and revs... Could that be it?? I havent check the O2 sensor or replace it but from all the info giving can any of you guys come up with an answer of what is wrong with this vehicle? This is the one i beat with my carina and 7afe... That proves it isnt running properly.

[Kwanza26]

It could be the O2... which is causeing the engine to limp... but to know for sure, check those codes. When the Check engine light is on, something is noticeably wrong. Take it to a shop or do the paperclip check and see exactly what it is...

[biglipzit]

We don't have professional shops in St. Lucia that would search out and find something wrong. Just a few guys that are licenced mechanics from the US that help everyone out... What is the paperclip test? I have tried everything along with the owner of the levin and the last thing i feel i have left to do is check the O2 sensor or some other sensor that may be going haywire and triguring that engine light and the slump in the powerband.

[toyotatech3]

take paper clip and cross TE1 and E1 in the data link connecter and then count the number of flashes

This post has been edited by toyotatech3: Jan 3, 2005 - 4:38 PM

[Coomer]

VVT(not VVT-i) shouldn't stay on until fuel cut. It's supposed to shut off around 7,000 RPM. Are you sure it's staying on until fuel cut at 8,300 RPM? Because if so, then you've probably got a problem with your ECU.

[biglipzit]

It shuts off at 7000rpm. How do i know which one is TE1 and E1 in the data link connecter? Any links i can go to that tells me?

[WannabeGT4]

Not the best picture but the quickest one I could find.


EDIT: This might explain a little better.
|------|------|
|.TE1.|.TE2.|
|------|------|
|..E1..|
|------|
There should also be a diagram on the bottom of the cover. This link might help as well. It won't work with ODBII cars 96? and up... I think. I know it didn't work on my 97 but the Advanced Auto Parts store did the diagnostic for me for free. Or you should be able to get the tool for about $20. This is also assuming that the Levin and Celica are similar when it comes to diagnostics. Not sure since I've never run diagnostics on them.

This post has been edited by WannabeGT4: Jan 3, 2005 - 8:45 PM

[biglipzit]

Ok i ran the test and i got 52 which is a knock sensor malfunction... That explains everything. The ecu is advancing the ignition and the kncok sensor isnt telling it when it has over advanced so the engine is knocking and losing power. Any idea where the knock sensor is and how to get to it on the 4age black top 20valve? I already read up on testing the knock sensor but i need to find it first. Thanks for all the help so far guys.

[WannabeGT4]

Does that look familiar to you? it's the one on the bottom according to this site.

[biglipzit]

I found that site too. The problem was that i am looking at this pic and dunno where on the engine it is. The engine bay is crammed with that blacktop 4age. Anyway i found that it is between the 2nd and 3rd cylinder underneath the intake manifold. Tomorrow i will have to go and remove the surge tank to get to it and check it to see if that is the problem. But if it works fine 5% of the time and doesnt work 95% of the time then would it be that or a wire in the knock sensor circuit that is being altered by vibrations? I really hope it is just a bad knock sensor and that i can go out and get one and have this car running again.

[Kwanza26]

I found that site too. The problem was that i am looking at this pic and dunno where on the engine it is. The engine bay is crammed with that blacktop 4age. Anyway i found that it is between the 2nd and 3rd cylinder underneath the intake manifold. Tomorrow i will have to go and remove the surge tank to get to it and check it to see if that is the problem. But if it works fine 5% of the time and doesnt work 95% of the time then would it be that or a wire in the knock sensor circuit that is being altered by vibrations? I really hope it is just a bad knock sensor and that i can go out and get one and have this car running again.
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It can't be under the intake manifold. That's a VSV for something or another... Diagnosis terminals are usually in plain sight just bolted onto the body... Oh... unless it's OBD2... which it probably is because you say Blacktop. That being the case, you have to take it to a shop or something and have it checked out. It must be checked with an OBD2 scanner... OBD2 terminals are usually inside the car.

This post has been edited by Kwanza26: Jan 4, 2005 - 1:41 AM

[Anub1s]

Umm...kwanza...

Ok i ran the test and i got 52 which is a knock sensor malfunction... That explains everything. The ecu is advancing the ignition and the kncok sensor isnt telling it when it has over advanced so the engine is knocking and losing power. Any idea where the knock sensor is and how to get to it on the 4age black top 20valve? I already read up on testing the knock sensor but i need to find it first. Thanks for all the help so far guys.
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[Kwanza26]

Umm...kwanza...

Ok i ran the test and i got 52 which is a knock sensor malfunction... That explains everything. The ecu is advancing the ignition and the kncok sensor isnt telling it when it has over advanced so the engine is knocking and losing power. Any idea where the knock sensor is and how to get to it on the 4age black top 20valve? I already read up on testing the knock sensor but i need to find it first. Thanks for all the help so far guys.
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Oh... oops... ;P