Pics of my rebuilt motor

[supramad77]

We guys, i have just had my second HG rebuild in as many years. Spent 6 months getting parts and cleaning up what i had. Lots of polishing and painting.
Still have some running problems though.
It won't idle and sounds very rough. Seems like it is drawing in air on the inlet manifold somewhere. Throwing up code 24 as well. I has swapped out the afm sensor but it made no difference.
Anyway i guess we will get it sorted out soon.
On with the pics.

 

[figgie]

by chance,

Has the EGR system been removed from the car?

 

[supramad77]

by chance,

Has the EGR system been removed from the car?

I think so.

 

[MK3Brent]

Very blue!

Thought you had a T4... anyway.. You probably have a vacuum leak and should be pretty straight forward to find.

 

[Sar-Supra]

Yep, it sounds like the EGR is causing problems. I had the same symptoms. Check the lines. I forget to connect the one which leads to the intake plenum on the right side of it.

I don´t have a picture but you should know which vacuum line.

 

[figgie]

I think so.

Ok

so that might be the culprit of your two head gasket issues. (detonation at low load/cruising).

Now on to the other side.

Triple check all hoses to make sure they are ON?
The intake, might want to take it off and put it on a straight edge.

 

[supramad77]

found the problem. One of the egr block off plates was not fitted to the top of the inlet mainfold. Sounds sweet now. simple fix that has had me scratching my head for a couple of days.

 

[figgie]

EGR Block off plate..... lol.

I hope you read my post (#6) about that!

 

[supramad77]

Yes i did . What can i say it was built by the best guys here in the UK. The block is not in great shape and if it goes again i will be looking for a replacement. they must know what they are doing i guess.

 

[7MGTEsup]

What Figgie is saying is it's not the engine that is at fault, when you boost on part throttle the TCCS holds the mixture at 14.7:1 till you hit 70% throttle. So if your pulling up a long hill on part throttle and your pulling boost the car will be detonating the whole time weakening your head gasket with evey second that passes. The EGR system serves two purposes 1. to quench nox and 2. to control knock on part throttle boosting.

 

[BlackDevilSupra]

...... The EGR system serves two purposes 1. to quench nox and 2. to control knock on part throttle boosting.

This is all fallacy.
Sole purpose of EGR system is an emission control device.
Knock and knock retard is facilitated by the knock sensor signal feedback + ecu.
What's evident is that often people here (in this forum) overextend and overshadow their knowledge of one subject with the ignorance of other... AKA "ego trip"

"Supramad", revisit Mk3Brent response above for possible solution to leaky intake system..

 

[7MGTEsup]

This is all fallacy.
Sole purpose of EGR system is an emission control device.
Knock and knock retard is facilitated by the knock sensor signal feedback + ecu.
What's evident is that often people here (in this forum) overextend and overshadow their knowledge of one subject with the ignorance of other... AKA "ego trip"

"Supramad", revisit Mk3Brent response above for possible solution to leaky intake system..

If its all FALLACY why do the Japanese spec ECU's have a different fuel and timing curve?

Please educate me if I'm wrong

 

[figgie]

This is all fallacy.
Sole purpose of EGR system is an emission control device.
Knock and knock retard is facilitated by the knock sensor signal feedback + ecu.
What's evident is that often people here (in this forum) overextend and overshadow their knowledge of one subject with the ignorance of other... AKA "ego trip"

Alot has been learned over the years. And specifically how damn brilliant those toyota engineers really were back then (even now more so).


Knock or knock control is part of the ECU but being an 8 bit CPU, minimizing knowck at all points would be an excersice in futility as most of that address space has to be used for fuel, ignition tables. detonation/knock at low load cruise rest squarley on the EGR system.

 

[jdub]

This is all fallacy.
Sole purpose of EGR system is an emission control device.
Knock and knock retard is facilitated by the knock sensor signal feedback + ecu.
What's evident is that often people here (in this forum) overextend and overshadow their knowledge of one subject with the ignorance of other... AKA "ego trip"

"Supramad", revisit Mk3Brent response above for possible solution to leaky intake system..

Fallacy? Perhaps more ignorance on you part

The knock sensors retard timing when they sense a 7 MHz signal...a very specific, narrow range. That does not happen under all knock conditions (i.e. part throttle, heavy load). The EGR's primary function is to reduce Nox emissions, but it also displaces air in the combustion chamber and the USDM ECU is tuned for it...all at RPMs above idle and less than ~4000 RPM. The resulting reduction in combustion temps has a huge effect on detonation in this RPM range.

If anyone is on a ego trip, it's you...fueled by ignorance, if not just flat stupidity.
Removing the EGR is a fools mod running a USDM ECU.

:: IJ. ::

 

[BlackDevilSupra]

No disagreement on 1

(2) You've just described the primary function of the EGR system, and any benefit w/r to knock control is strictly unintentional.

Vehicles that lack EGR has the same amount of knock suspressant / control as those without EGR, because the knock sensor feedback + ECU will be performing as designed. On the other hand, their emissions control won't be on par.
This ends my contribution to this thread, since it's apparent that there won't be any concession.

Fallacy? Perhaps more ignorance on you part

(1)The knock sensors retard timing when they sense a 7 MHz signal...a very specific, narrow range. That does not happen under all knock conditions (i.e. part throttle, heavy load).

(2)The EGR's primary function is to reduce Nox emissions, but it also displaces air in the combustion chamber and the USDM ECU is tuned for it...all at RPMs above idle and less than ~4000 RPM. The resulting reduction in combustion temps has a huge effect on detonation in this RPM range.

If anyone is on a ego trip, it's you...fueled by ignorance, if not just flat stupidity.
Removing the EGR is a fools mod running a USDM ECU.

:: IJ. ::

 

[jdub]

There won't be any concession because you are wrong...simple as that.
Your "contribution" is the usual "this is how I think it works" BS you see here way too often.

Care to explain what happens when extra air takes the place of inert exhaust gas during combustion when the ECU is metering a set amount of fuel at a given RPM (i.e same amount of fuel and more air)?

Knock sensors are like "explosion detectors"...they sense knock after the fact and are just as useful. The TCCS also reduces timing when coolant temps go above 210 deg F. Why? To reduce the chance of detonation. I'm pretty sure the Toyota engineers were smart enough to incorporate preventative measures to prevent detonation...the EGR performs this function as well. The knock sensors are the last ditch save for the motor.

My comment stands...only fools remove the EGR and run the USDM ECU. Especially since it has no effect whatsoever on top HP produced (it shuts off above ~4000 RPM).
Guess you're one of them.

 

[figgie]

Knock sensors are like "explosion detectors"...they sense knock after the fact and are just as useful.

You know, I know I have heard that somewhere.. wonder who was the smart person to come up with that. =)

 

[jdub]

And a VERY accurate term too

In support of what I (and others, besides BlackDevil) said above, Toyota used more than one scheme to prevent detonation:

This Toyota Tech Article discusses timing corrections.
http://www.autoshop101.com/forms/h25.pdf

Page 22...middle:

As the engine temperature approaches overtemp, the ECU will advance spark when the IDL contact is on, to prevent overheating. When the IDL contact is off, the ECU will retard spark to prevent detonation. Advance and retard shown on the graph are corrections to the basic advance angle.

Page 24...top right:

EGR Flow Correction
This strategy advances timing from the basic calculation when the IDL contact is off and the ECU is commanding EGR flow. This correction allows the engine to operate more efficiently because it resists detonation when EGR is introduced into the cylinders.

And our resident genius is trying to tell us it's all knock sensors. It's pretty obvious Toyota recognized the value of the EGR in suppressing detonation...they even incorporated it into the timing tables.

 

[Davismj711]

Great looking engine !! Could you tell me about your Fan Shroud ? Looks real good.

Curious about what type of battery that is also.

As far as the EGR, I am with the leave it be crowd ^^

 

[supramad77]

Great looking engine !! Could you tell me about your Fan Shroud ? Looks real good.

Curious about what type of battery that is also.

As far as the EGR, I am with the leave it be crowd ^^

As for the egr the guys that built the motor said that the UK cars had a different set up to the US cars and therefore were not affected by it being removed. Ed also said that he had yet to find a UK supra with a working egr system anyway.

We have very different emission laws over here than you do.

The fad shield only cost around £20 of a guy on ebay selling universal shrouds.
The battery is made by bosch.