Rebuilt 4age bigport no spark

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jondee86
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Re: Rebuilt 4age bigport no spark

Postby jondee86 » Tue Nov 01, 2016 2:50 pm

Sounds too loud for a tappet ticking, and goes away too quickly when you rev the
engine. More like a bad cam belt tensioner bearing. Did you replace the tensioner
when you rebuilt the engine ? I have never heard an injector tick... usually you need
a stethoscope or to use a fingertip on the injector to "feel" if it is working.

There are opposing views on how to break in a new engine. Some people say you
need to be gentle on the engine for a long time, and others say load it up as soon
as it hits operating temperature. I used the Mototune USA technique, and my engine
was ready for normal driving half an hour and about 25 km after first start up.
http://www.mototuneusa.com/break_in_secrets.htm

If Lamborghini can run up their engines on a dynometer to check maximum power,
that tells me there can't be any serious downside to loading up a new engine.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

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mr2mk1hero
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Re: Rebuilt 4age bigport no spark

Postby mr2mk1hero » Wed Nov 02, 2016 12:05 am

I replaced the tensioner bearing with a brand new one and tightened the screw to the same Nm as per BGB.
Don't let it fool you, its not this loud, I just got a directional mic really close to the engine to isolate the sound. It reality the sound is less prominent. Tho I can hear it inside the cabin when I concentrate on it. Hmmmm

I loaded up the engine when I got it warm. The same mototune technique makes 100% sense to me. Apply throttle and then release throttle. Repeated that several times. After that I have been more conservative, but I did hit 5, 6k rpm several times. Can't resist honestly.
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jondee86
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Re: Rebuilt 4age bigport no spark

Postby jondee86 » Wed Nov 02, 2016 2:41 am

OK... well, if the sound is coming from the top of the engine, you
may have to take the cam covers off and check the shim clearances.
If you find one that is looser than factory spec, re-shim that one and
see if the sound goes away.

If you don't find a loose one, then at least you can cross that off your
list of possible causes.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
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Re: Rebuilt 4age bigport no spark

Postby mr2mk1hero » Fri Nov 11, 2016 5:28 am

So here's a bit of an update:

Opened up the cam covers, checked the shims, all are nicely within spec. I expected that, but needed to make sure. I will try and swap out the injectors to see if it changes the sound next.

Other than that:

Car has done around 150 miles so far. I have changed the oil 3 times. Right now the car has its fourth batch of oil inside. The last oil that came out yesterday looked almost new. Its not colored by assembly lube anymore.

There is still particulate on the magnet of the oil sump bolt. But it is slowly reducing itself. There's some sludge and some extremely small particulates on it. The contents are always the same but the amount is reducing itself. When I wiped it with a tissue its impossible to feel the particulate between the fingers. It just stains the tissue grey.
I managed to take a relatively good picture this time? What do you think?

Image

Here are the possible culprits I managed to come up with so far, in order of probability
1 - Head porting residue. The machine shop claim they washed it and that I could install it straight away. I trusted them. But probably they couldn't get rid of all the porting residue. The particulate looks closest to the porting residue
2- Block not clean enough. I cleaned the block the best I could, but all I had was cold water from a compressor powered washer. But I cleaned it like 6 times until the water coming from the oil channels was not 100% clean. I used to a lot of wd-40 on the oil channels afterwards because I was afraid they would rust in the time it took me to assembly and install everything. WD-40 could be to blame? But I think it evaporated in the 2 months i spent assembling and installing everything.
2 - Piston rings? But it should have stooped by now.
3- piston bores? No way right?

So based on the photo....any clues? I'm happy it is reducing itself, although I'm not happy by the time its taking to disappear. Maybe once its gone my compression will be gone too?

I also figured out my TPS was a bit out of whack too. It bucked and jerked at low throttle. Re-adjusted and car feels a lot better now, much more driveable, feels more responsive too. It will still die if I screw the idle air screw on the TB all the way down. MPG seems to be lame, although I think its the fuel gauge, because it was showing I was in the middle of the last 25% of fuel and once I refilled to the top all I could fit inside the tank was like 20 litres of fuel.
I was a bit reluctant to fully rev the car because of the particulate but it did get close to 7.000, it feels pretty good, a lot better after TPS adjustment, but I think the power curve is a bit weird still. The car seems to somehow pull better at lower rpms than higher ones, like 3 and 4 k is better than 6.

Also, car stalled completely randomly twice yesterday when coming slowing down to a stop. Fires right back up and then it doesn't happen again. Have 0 clues why this happened, never happened before.
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s24a
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Re: Rebuilt 4age bigport no spark

Postby s24a » Fri Nov 11, 2016 7:24 am

Well, if it was head porting residue, it would be aluminium and that is not magnetic.
So I think you can eliminate that as the source, although pan sludge that does NOT stick to a magnetic could be porting residue if you see it in drain oil.

I am going to place my bet on block hone residue.
When you put the engine together did you wipe the bores repeatedly with cloth towels soaked in brake cleaner or acetone until the towels came out clean?
If not, then the hone "dust" can settle in the surface of the block and under the pressure of the rings running past the bores with oil on them can "pressure wash" these particle out.

Since when you feel the particles you cannot really detect them, you should be OK.
Again I suggest with each break-in oil change that you cut open the filter and see what is there.
If the oil filter looks clean, then stop worrying....

Hank
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson

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Re: Rebuilt 4age bigport no spark

Postby mr2mk1hero » Fri Nov 11, 2016 9:12 am

But magnets stick to the head. Doesn't that mean the porting residue is magnetic too. Its not pure aluminium but some alloy right?

I did not wipe the bores with anything at all. Just put a bit of assembly lube on them. Didn't think they need cleaning? I cleaned everything else like a million times but didn't touch the bores. Crap. Is that a bad thing now?
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What is done cannot be undone....

Postby jondee86 » Fri Nov 11, 2016 2:10 pm

Your phote seems to show what might be descibed as a black greasy blob sitting
on top of the sump plug. Presumably there is some magnetic content in there as
well, which will be iron from the bores.

The crud that sticks to the inside of a used engine and in the oil galleries is not
water soluble. So although you will have knocked all the loose stuff and big lumps
off with a pressure washer, there will still be a certain amount stuck to the inside
surfaces of the engine. Fresh engine oil has some "cleaning" action that will slowly
remove surface crud over time.

Your filter will remove circulating particles in the size range that causes wear, but
oil velocity in the sump is low other than directly under the pickup. Small particles
that get into the boundary layer on the bottom of the sump may not get swept to
the pickup, and some will get close enough to the magnetic plug to be caught. As
suggested, looking inside the filter will give a better picture of what is being
circulated with the oil.

Plain mineral oils (without any friction modifiers) containing extra zinc are most
often recommended for engine break in, as they do not interfere with the ring
bedding process. Assembly lube (which may contain moly) should only be used on
high load surfaces such as camshafts and bearings.

So it seems to me that your engine is likely purging itself of residual crud, and
flushing out particles from the machining and break in processes. Since you have
already changed the oil several times, I'd suggest it is time to give that engine
a serious workout :)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

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Re: Rebuilt 4age bigport no spark

Postby jondee86 » Fri Nov 11, 2016 7:23 pm

mr2mk1hero wrote:I was a bit reluctant to fully rev the car because of the particulate but it did get close to 7.000,
it feels pretty good, a lot better after TPS adjustment, but I think the power curve is a bit weird still.
The car seems to somehow pull better at lower rpms than higher ones, like 3 and 4 k is better than 6.

Also, car stalled completely randomly twice yesterday when coming slowing down to a stop. Fires right
back up and then it doesn't happen again. Have 0 clues why this happened, never happened before.

Here is a dyno curve for a 4AGE thoughtfully provided by oldeskewltoy...

Image

The engine is modified and AFAIK still retains the TVIS system. Disregard the actual numbers but
look at the shape of the torque and power curves. The torque curve is essentially flat with two small
bumps. And this is why you need to work the gears and keep the revs up if you want to get "spirited"
performance from a 4AGE. Roll-ons in 4th or 5th are not an AW11 (or AE86) strong point :)

Stalling when rolling to a stop with a hot engine is typical of the IDL switch in the TPS not changing
state when the throttle closes. If the switch does not change state the ECU will not make adjustments
to fuel and ignition timing to stabilise the idle. AE92 smallport engines and 20V have a PWM idle air
valve that opens to let in extra air when engine rpm drops and help prevent stalling. TVIS engines don't
have this feature, so correct idle speed and TPS setting are are important for on and off idle transitions.

Cheers jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

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Re: Rebuilt 4age bigport no spark

Postby oldeskewltoy » Sat Nov 12, 2016 10:47 am

sorry jondee... that one is not TVIS(largeport), that is a smallport

my 2 largeports... top one Web 294 cams, with 10.3:1 compression... no head work

Image



and this one is Skippy... fully ported head, stock cams, 10.75:1

Image
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

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Re: Rebuilt 4age bigport no spark

Postby jondee86 » Sat Nov 12, 2016 12:24 pm

@ oldeskewltoy
Thanks for the clarification. Maybe a better way of making the point I was
getting at would be to say... when you don't have a lot of torque, use the
gears and keep the revs up
:)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
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Re: Rebuilt 4age bigport no spark

Postby mr2mk1hero » Mon Nov 21, 2016 1:27 pm

A bit of an update. Thanks for the torque and power curves. Right now that is a distant dream for me. Car is definitely slow.

Took the car to have some rust removed and parts repainted. On the way back had a little race against my daily driver, A 107 bhp 1.6 16v suzuki sx-4 crossover type car with my wife behind the wheel. This car does a -60 run in 10.7 seconds according to the factory numbers. We did a run from a standstill and one starting in 4th gear from 70km/h. Both times the family crossover was noticeably faster than the MR2. How embarrassing.

Engine feels solid but there is definitely something choking or preventing the car from running right.
So today I rolled up my sleeves and did some more troubleshooting:
1- Spark plugs are ok definitely. Look completely normal.
2- T-vis is working fine
3 - Diagnostic mode doesn't show any faults
4 - AFM is spot on, measured it twice today
5- TPS resistance is also spot on, as per BGB
6- Timing is 10 btdc in diagnostic mode and at 800 rpm
7 - Car still dies if I screw the idle air screw on the TB all the way down.
8 - Can't find absolutely any vacuum leaks
9 - Tried unplugging the vacuum line to the fuel pressure regulator while car was running - car seemed to run worse.

I made a video of me removing plugs while the car is running. Let me know if this tells you anything.
https://youtu.be/fPwvrA4C8rI

Here's another video of the crank pulley while the car is running and a timing light pointed at it. Why is the pulley jiggling like this, it is supposed to behave like this?
https://youtu.be/EvjvKM1BsHc

Some more weird stuff I found. I tried moving the injectors back and forth and when I move the injectors with a bit of force they leak fuel. A stream of fuel comes out when I move the injectors. Absolutely no fuel is leaking when I am not touching them. Is this normal?

Any suggestions are welcome. I must be missing something. I just wanna experience this car run as it should. Waiting more than 2 years for it.
Check out my YouTube channel: https://www.youtube.com/channel/UCwosUn ... xtqkNJ3Fbg
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Heaps of 4A-GE and MR2 mk1 aw11 content on both.

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Re: Rebuilt 4age bigport no spark

Postby s24a » Mon Nov 21, 2016 4:18 pm

Bit of a SWAG (Super Wild Ass Guess) here, but possibly the ECU has some issues?
Have you taken the cover off and checked the electrolytic capacitors for any leakage or bulging ones that may have changed values due to deterioration?

This is a BIG issue on 20V Silvertop ECUs, and also on Blacktop ECUs to a lessor extent (maybe due to age since they are later ECUs?).

Your ECU might have this as an issue, and if so, either a new ECU or replacing the electrolytic capacitors in your present ECU could help a great deal.

If your capacitors show leakage, you need to clean the board in that area thoroughly with non-chlorinated brake cleaner to remove the capacitor fluid residue and the humiseal (conformal coating), then check the traces for etching. Replace the capacitors with good ones (Panasonic brand I like) and also repair any corroded traces with solder or flywire and solder. Recoat the board with humiseal or acrylic coating, and hopefully that cure the issue.

Replace ALL electrolytics if you find even just ONE to be suspect. Good insurance.

Hope this helps.

Hank
"When the going gets, wierd, the Wierd turn Pro" -- Hunter S. Thompson

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Re: Rebuilt 4age bigport no spark

Postby mr2mk1hero » Tue Nov 29, 2016 1:24 am

Thanks for the tip s24a, I will take a peek at the ECU, although I don't suspect it yet.

I think i actually finally figured out the culprit for the poor performance, it is the TPS after all.

The last time I managed to set it up and do the measurements and they were all within spec with the right thickness gauges in and everything. I re-measured again today after a few days, and its all again totally out of spec.

So I took the throttle body off, brought it home and this is what I found out. I managed to set it up and get it within spec. But as soon as I open the throttle all the way it all goes out of whack again. After doing this a few times the tps can't even be adjusted anymore at all. I now can't get my multimeter to measure continuity when I have the thin thickness gauge (0.35mm) in, no matter where I move the TPS. This means its 100% dead right?

So I ordered a new used one with the same number on it as mine. Mine is 89452 - 20070. Toyota dealership can't get it, its discontinued.
I looked everywhere but I can't find a new one with the right number that will ship internationally anywhere...Any ideas?
I can find plenty of 89452 - 20050 on ebay. Will it work?
I managed to find this too http://www.ebay.com/itm/311550269789...witem=&vxp=mtr
I think this fits because I found on toyodiy that 20070 also goes on the fx16. But its so expensive and not even OEM...I did send a pm to the seller just to make sure its 20070.
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