The comprehensive 4age thread

[Jonathan_337]

Thanks for the response, he had an electrician friend so he's gonna try and get him to check the sensors. How exactly do you run a diagnostic on it ?

I know up to this much --> http://www.toyotagtturbo.com/forums/sho ... stics-Test

But what is attached to the other end of th wire ? I personally like knowing to fix my own stuff so an knowledge I gain is very much appreciated.

[Hook]

The link to the thread I posted has how to retrieve the error codes and decode the numbers.

The quote was from that same thread, just from a post specifically about transmission error codes.

[Team Loco]

Guys. Who is the best 4age blacktop mechNic out there? Its been two years now our replica caterham has had power loss issues at high revs and i am really getting fed up of spending dollars to repair and we still have the same issue. Basically at drag and wind when the car is only on the right side track, we lose power at the top. The engines dies right down. This inly happens on the right side track when the car leans to the left. We were thinking gas flow or electrical issues but all those have been checked. I need a good troubleshooting mechanic..

For those who dont know my car, it is powered by a blacktop rear wheel drive. Its a locally built car from chassis go right up

[Hook]

I see you said you've covered fuel as an issue, how though? Is there a baffle or stilling well in the tank around the fuel pump? I know you guys are very thorough, but I still hafta ask.


The older model 4A-GE (redtop IIRC) had an oil feed problem on hard cornering, so a re-designed sump was sold for that model and continued to be used in all succeeding generations. It's possible that the rolling forces exerted on the engine might not be what the sump was designed for.

Tipping to the left would simulate the car leaning steeply to the rear in it's normal FWD configuration. That would mean oil could be draining back, away from the strainer. Diminished oil pressure could well negate the VVT.
Is there an oil pressure gauge to see if oil starvation is an issue, or have you already circumvented this with a dry sump kit?

[Jonathan_337]

Having another problem with the 4age, it's a silvertop 20v.. Revving at high RPM's leads to a loud knocking/tapping sort of noise sounding like its from the top of the engine, not the bottom where the bearing is. Any idea what that could be ? From the research I've done it seems to be either related to the bearing (which is at the bottom though), the VVT cam gear or simple things such a spark plugs. Anyone had any experience with this noise? It's only if I kick down and hit about >5500rpm it starts.

[Hook]

Are you certain it's not bad pre-ignition? I skipped a tooth a long time ago due to a loose tensioner and it caused severe knock in VVT, even in neutral.
Line up the cam gears and make sure the crank pulley is on zero.

[Jonathan_337]

I can do the basic stuff but I don't think I'm that good yet, I'm gonna send it to a mechanic (has a Blacktop himself and it works amazing, so he should be good with them) and have him check thru. I just wanna get an idea of possible causes so I wouldn't get overcharge for things he didn't do.

[Hook]

It's easier than you think. I like to try to learn to do as much as possible for myself - I hate getting a 6 for a 9.

Take off the cam gear cover, remove the plugs and rotate the engine clockwise slowly with a 19 socket and a power handle to make sure the timing marks line up like this:

Then shine a light on the crank pulley and make sure the timing mark below lines up like this:

[Jonathan_337]

It's easier than you think. I like to try to learn to do as much as possible for myself - I hate getting a 6 for a 9.

Take off the cam gear cover, remove the plugs and rotate the engine clockwise slowly with a 19 socket and a power handle to make sure the timing marks line up like this:

p932417924-5.jpg

Then shine a light on the crank pulley and make sure the timing mark below lines up like this:

TDC2.jpg

Thanks for that. I checked the timing today and it was HORRIBLY off. The entire spindle is dislocated. I'm having a friend who works in Toyota and knows these engines coming to check it tomorrow. The knocking got a lot worse as well, so I'm praying for that the timing may be it.

[Hook]

What did u mean by "The entire spindle is dislocated."?

The timing mark on the pulley isn't super precise though. Even if you're spot on, it'll be a little bit off the mark, but it's a pretty good indicator of where you're at. When u take off the pulley and cover you'll see the mark you're supposed to use.
Thankfully, the silvertop is a non-interference engine so u wouldn't have bent anything, but get that corrected ASAP.

[Jonathan_337]

What did u mean by "The entire spindle is dislocated."?

The timing mark on the pulley isn't super precise though. Even if you're spot on, it'll be a little bit off the mark, but it's a pretty good indicator of where you're at. When u take off the pulley and cover you'll see the mark you're supposed to use.
Thankfully, the silvertop is a non-interference engine so u wouldn't have bent anything, but get that corrected ASAP.

There's a mark on the gear like, the top right one that's supposed to line up with a mark on the case itself (idk the exact name of it, now learning about these things) and its WAY off.. I showed it to the Toyota mech and he told me. Tomorrow I'll take some pics of what exactly I mean and upload it to help anyone else who may be having similar problems. It should be fixed tomorrow, I'm hoping that stops the knocking now though. It's extremely loud. I'll update this tomorrow.

[Jonathan_337]

Well the reason for the knocking is mainly cuz the car my friend bought was worked on by some stupid people. They put a blacktop head on a silvertop block and that's why the timing was so off. The cams weren't lining up so by guess they adjusted the timing and distributor till it could start. He's gonna change the entire head and block together. He's getting a blacktop head and block at a reasonable price, but with reusing all the peripherals from the silvertop and just the blacktop head and block, would the ECU work? I know the Blacktop's airflow is a MAP sensor while the silvertop is AFM sensor which is why I ask. A Toyota tech told me it will, just wanna gain some reassurance.

[Hook]

I hope you're looking at it correctly. Remember there are TWO timing marks on each cam gear - one each to line up with the notches on the tappet cover and one each to face each other, ie.
Intake cam gear has marks at 12 and 3 (one dot each)
Exhaust cam gear has a notch at 9 and a dot at 12.

Here's the repair manual for the blacktop. most of it is applicable for the silvertop as well.
http://www.locost7.info/mirror/4age_blacktop.php
==========================================================================
A blacktop head on a silvertop block will work just fine, except with a lowered compression ratio.
Here's why:

Silvertop:


Blacktop:


Notice the milled away area making the blacktop combustion chamber rounded at the top while the silvertop combustion chamber has a "star" shape? The shape of the blacktop piston crowns make up for this and then some, because the blacktop actually has a higher compression ratio, BUT this head on a silvertop block will lower your compression unless the head or the block is milled to compensate. It's more trouble than it's worth really.

Once you're okay with not doing any of that tweaking, setting up the valve timing is the same procedure for both - same markings. I say try it this way first before you jump out the money for a head n' block. You might like it *shrugs*.

==========================================================================

Now, about your question on swapping out for a blacktop head n' block.
If you'll be using ALL the silvertop peripherals and ECU you'll be fine. It'll work.
Ye olde seat-of-the-pants-dyno will tell you you'll actually be a tad faster than a complete silvertop, owing to a better flowing head, lighter internals and (again) a higher compression ratio, but whether you'll be faster than a complete blacktop is also debatable since the fuel trim is different and the silvertop intake is a bit more restrictive than the blacktop (cross sectional area of the BT intake is bigger).

I've seen identical model cars run with the only major difference being BT/ST, bone stock and blacktop barely won. I've also driven a well-tuned AE100 in B'dos with a BT head on a ST block 6fwd and it pulled really nicely, but arguably not as well as a complete ST.

Choice is yours, but it shouldn't cost anything to set the timing right on the engine first before you start digging up. I'd exhaust that option first. The last thing you want is your car down to swap an engine three weeks before the end of the year - sticking is imminent and transport is necessary.

[demogorgon15]

I Don't know if this would be an issue but what timing belt are you using? If the bottom end is from the silvertop, your oil pump is more than likely from the silvertop and you should be using a silvertop timing belt. (or so I've read)

[Hook]

^^^ good call! I kinda assumed the only thing blacktop in the car was the head.

ST uses a 111teeth belt, right?

[demogorgon15]

ja silvertop uses 111 round tooth and the blacktop uses 110 round tooth

[Hook]

Oil filters!

Factory oil filter part number for 4A-GE 20V is:
90915-YZZF1

Equivalents:

Purolator #L14476
Fram #PH4967
STP #S4967
Valvoline #VO40
K&N #HP1003

[Bigmanbandy]

Guys. Who is the best 4age blacktop mechNic out there? Its been two years now our replica caterham has had power loss issues at high revs and i am really getting fed up of spending dollars to repair and we still have the same issue. Basically at drag and wind when the car is only on the right side track, we lose power at the top. The engines dies right down. This inly happens on the right side track when the car leans to the left. We were thinking gas flow or electrical issues but all those have been checked. I need a good troubleshooting mechanic..

For those who dont know my car, it is powered by a blacktop rear wheel drive. Its a locally built car from chassis go right up

Check the toyota guru as he is sometimes called. His real name is Simmons. Location San Juan. I think that I know this car. It had a 4AGE license plate to the back. Had a padna with this same exact problem.

[new gt]

not because u use a b\t head on a silver top bottom end it is wrong .we have done this and it works find.both heads work find ,its the timing the man fleckup.

[Team Loco]

hi guys, anyone know where i can get blacktop valves to buy? we bent ours on sunday in drag and wind. need new or used asap. cash on the spot.

thanks
TL

[Hook]

pressure! you might have to buy a head and cannibalize it though
viewtopic.php?f=6&t=469507&hilit=head+blacktop

[Ted_v2]

might i ask how did that manage to bend?
timing was off?

[Bigmanbandy]

Are silvertop valves and blacktop valves different in any way?

[Hook]

Not to my knowledge. But I never had both sets on hand at the same time with a scale and a verniers.

[Bigmanbandy]

Well I have a couple of silver top heads lying around.

[Bigmanbandy]

viewtopic.php?f=32&t=483579&p=6881183#p6881183

[Ted_v2]

brisk question

how does the manual and power mode work in these trannys? AT

someone told me the manual mode allows you to shift thru the gears 1-2-D
and the powermode redlines each gear @ D
and well normal mode is normal

[Team Loco]

might i ask how did that manage to bend?
timing was off?

nah, the entire crank pulley ran loose and spun out. hence timing went off and well.....bent valves. been sorted out since but we've parked her up awaiting the perfect person who can do some tuning. our knowledge is limited so we a bit picky as to who can help us out. we are thinking of audi from central. the guy with the dyno. heard he is good

[ST205_GT4]

what about using a 4agze?? is that an option?? or you staying with the 20valve...

[Bigmanbandy]

brisk question

how does the manual and power mode work in these trannys? AT

someone told me the manual mode allows you to shift thru the gears 1-2-D
and the powermode redlines each gear @ D
and well normal mode is normal

X 2
And what I would like to know is if using an auto harness with a box will it make a difference to have a power mode and manual switch installed?