4AGE small port timing/EFI question

[Golberg]

Haven't really posted much around here as you might notice by my post count, but I've got a couple of AE71's one of which I'm doing a 4AGE conversion on.

As I read another thread something dawned on me.

I just replaced the timing belt on my smallport 4AGE exactly as the old one was. Long story short, my small port motor was running a bigport loom and ECU when I got it. I decided it was a better idea to run the proper smallport ECU so I got together the things I need which from memory was only a dizzy, loom and ECU. Anyhow, when I replaced the belt, the mark on the harmonic balancer wasn't even close to the little markings on the timing cover, probably about 30 degrees away. Figured since I just swapped over the belts exactly as they were (marked them, transferred marks, triple checked) it must be ok.

What I'm wondering now is, is it possible timing belt been put on differently to suit the other computer? Or am I just a paranoid idiot?

Cheers for the advice.

[biggo]

you are correct

small port computer fects up the timing alot, but can be made to work.

grab the manual of the interweb and follow that. it should work sweet assuming you got all your shit wired up propper

[Golberg]

*sigh* Why did I realise this after I dropped the engine in.

This manual you speak of, is this the one which covers the bigport? That's the only one I've ever found on the net. If so do I just follow the instructions as per that manual?

Or is there a smallport version?

Thanks for the advice

EDIT - One thing which I just checked out, after 6 full revolutions the marks lined up with the +5 which is correct isn't it?

[biggo]

a 16v is a 16v

manuals are the same, electrics are not

have you tried aligning the cam wheels with the indents on the cover yet?

[Golberg]

Well before I took the belt off I lined the 2 top indents up with one another but I couldn't see any bottom one (perhaps there was grease covering it or something). I am certain that the new belt is in exactly the same position as the old, and both those 2 marks line up at the same time.

I really should do this stuff before I reply, just pulled the top timing cover back off, the 2 cams line up with their marks and the harmonic balancer lines up with the 5 on the left of the 0 (presumably +5?). Thats probably all that I can check out without pulling the balancer off which would be a bit of a pain. Any chance that it is correct as it is?

[biggo]

there are 2 marks on the cam gears

the 2 sraight ones face up in line with the indents on the cover, there should be 2 mor indents on the bottom about 30 degress out.

get a timing light? crank is meant to be +10 degress TDC

[Golberg]

So basically, if I go and make sure each little notch lines up with its corresponding one on the cams and the crank and slip the timing belt on I can't go wrong? But it would be a good idea to check it with a timing light afterwards to make certain it is correct?

Coming from another angle, what exactly would one have to do to the timing to make a stock small port run on a bigport computer? As far as I can tell all the timing belt pulleys are the stock ones (unless bigport ones are different and have been swapped on). And there isn't any way to adjust the timing without using adjustable cam pulleys is there? unless you count moving the pulley one notch over. So in order to run the engine the previous owner must have done that right?

Sorry about the mass of questions, just trying to get my head around all this.

Thanks a lot for your help though.

[gumbie]

<div class='quotetop'>QUOTE (Golberg @ May 22 2008, 11:01 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=535424)</div>
Well before I took the belt off I lined the 2 top indents up with one another but I couldn't see any bottom one (perhaps there was grease covering it or something). I am certain that the new belt is in exactly the same position as the old, and both those 2 marks line up at the same time.

I really should do this stuff before I reply, just pulled the top timing cover back off, the 2 cams line up with their marks and the harmonic balancer lines up with the 5 on the left of the 0 (presumably +5?). Thats probably all that I can check out without pulling the balancer off which would be a bit of a pain. Any chance that it is correct as it is?[/b]


If I understand you correctly then you have the timing belt on the crank one tooth out of position. The harmonic balancer should line up with the zero on the timing cover when the cams are lined up with the indents in the top timing cover.

[riceburner]

86 Nick is correct, if your cams are in correct location and the balancer sits on 5deg then its out of wack. Crank needs to be top dead center when setting the cams.

Take the belt off, set the crank THEN set the cams. Easy as.

[Golberg]

<div class='quotetop'>QUOTE (FKN16v @ May 26 2008, 05:45 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=536946)</div>
86 Nick is correct, if your cams are in correct location and the balancer sits on 5deg then its out of wack. Crank needs to be top dead center when setting the cams.

Take the belt off, set the crank THEN set the cams. Easy as.[/b]
Well, I just took the harmonic balancer off and the notch on the crank timing pulley lines up with the one on the oil pump and so do the cam ones line up. So I'm pretty sure there is nothing wrong on the timing belt after all that, so is that to say only the spark timing is different on the small port? I've got a small port dizzy so I can't imagine I'm likely to have any problems after all that. I guess we'll see where the harmonic balancer lines up when I put it back together again.

[gumbie]

<div class='quotetop'>QUOTE (Golberg @ May 26 2008, 10:36 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=537144)</div>
Well, I just took the harmonic balancer off and the notch on the crank timing pulley lines up with the one on the oil pump and so do the cam ones line up. So I'm pretty sure there is nothing wrong on the timing belt after all that, so is that to say only the spark timing is different on the small port? I've got a small port dizzy so I can't imagine I'm likely to have any problems after all that. I guess we'll see where the harmonic balancer lines up when I put it back together again.[/b]


If all the timing marks on the front of the motor line up then check that the rotor button in the dizzy is lined up perfectly with number 1 on the cap. If it is then it sounds like the dizzy or ecu are faulty. Try putting in another dizzy and see what happens.