4AGE 20V missing

[91 ZERO]

Have purchased an AE82, with a 4AGE 20v blacktop. Runs a factory 4AGE 20v computer. Engine wise, it is relatively standard (no air filter set up which I am about to change though). Previous owner last raced it many months ago and has been sitting idle since. He hasn't changed anything since then either.

It starts fine and idles sweet (maybe a little high at around 1300rom when cold). However under load - driving up a steep drive/moderate or heavy load it misses/hesitates like nothing on earth. It feels like it wants to go, but jerks heavily.

I initially thought ignition, so I have replaced:
Plugs
Leads
Dizzy cap
Rotor
oh - and a new fuel filter as last one was clogged.

After all that, it still does misses like crazy. I am now thinking possibly the coil pack, or possibly the fact that the fuel in the tank is totally sh!t house. Anything else I should look at? Is a diagnostic worth a shot to try pick up an error code?

Cheers

[BZR4AGE]

one of the great mystries of a 20v blacktop. I have the same issues. have done all the things you have plus knock sensor and oxygen sensor. Also done coil and ignition with another one. Still does the same thing.

Only thing left I haven't check was fuel pump and injectors.

Know another member on here having the same problem, i think he has given up and selling the car now.

Heard another member solved it by replacing fuel pump.

I am keen to find out what it is too.

[91 ZERO]

Cheers, but not what I wanted to hear! Damn. Well I will get the injectors checked out/cleaned, and try the fuel pump too. That'll be next on the list then Will let ya know how I get on.

[BZR4AGE]

just to let you know, I've rebuilt my engine too and it still does the same thing, so I can rule out the engine being at fault.

and I am using Link ecu now, so knock and oxy sensor are not used, so those are out of the questions.

so yea, my next thing to try too is fuel pump and check injectors

[touge_ae101]

how recent was the 20V swap? might pay to check the corresponding fuel pump is in the right place

[91 ZERO]

Thanks for your reponses.

It was done about a year and a half ago, he had raced it a lot with this engine, and had no probs.

Well I will drain the fuel tank this weekend, clean it out, and put some fresh 98 octane in, and replace the fuel pump. Fingers crossed. Will post up how it goes.

[matt dunn]

and I am using Link ecu now, so knock and oxy sensor are not used, so those are out of the questions.

So you are using a LINK ECU as a stand alone ECU not a piggy back
and it still does it?
I presume this is the stutter/hesistation that they have especially when cold?

I always assumed it was an ECU related problem, and never bothered to try to fix our one, but if not I may have a go at it.

Matt

[sergei]

I fixed all the stutter on mine by replacing leaky caps.

[BZR4AGE]

and I am using Link ecu now, so knock and oxy sensor are not used, so those are out of the questions.

So you are using a LINK ECU as a stand alone ECU not a piggy back
and it still does it?
I presume this is the stutter/hesistation that they have especially when cold?

I always assumed it was an ECU related problem, and never bothered to try to fix our one, but if not I may have a go at it.

Matt

Yep, stand alone ECU, and no it slutters when ever it feels like, not just when cold. I also notice it misses when idling on a gradient/slope, and the slutter happens usually when start stop situation at a intersection if the intersection is on a slope....so I have a feeling is slope related.

[cat007]

Slope related to me sounds like a fueling problem. Don't suppose you know anyone with either a dyno or a LM1 wideband?

When it misses, does it pump out black smoke out the exhaust?

I'd be inclined to change the fuel pump and/or injectors and/or fuel pressure regulator

[BZR4AGE]

The funny thing is, when we went around puke on a test day with a wide band...the A/F was perfect even when sluttering....

Thats why is a BIG MYSTERY!!!! if it was definately the fuel pump at fault, I would expect the engine to lean out. But then, there is nothing else I can think off that Link controls that standard ECU also controls. (I make this comparision because my sluttering happen even when I had stock cams and stock ECU).

[cat007]

Please stop saying sluttering. It's causing me to nurse a semi

[BZR4AGE]

The funny thing is, when we went around puke on a test day with a wide band...the A/F was perfect even when jerking....

Thats why is a BIG MYSTERY!!!! if it was definately the fuel pump at fault, I would expect the engine to lean out. But then, there is nothing else I can think off that Link controls that standard ECU also controls. (I make this comparision because my sluttering happen even when I had stock cams and stock ECU).

Fixed lol!

[.:O4AGTZ:.]

Please stop saying sluttering. It's causing me to nurse a semi

haha that was so blatant I couldnt hold my laugh in in my quiet office. needless to say i got a few looks.

[neo]

subscribing to the thread

My silvertop daily has always done this, especially when the air temp is cold [winter], and low revs, low - moderate load.

Anyone swapped out the coil + ignitor?

[BZR4AGE]

subscribing to the thread

My silvertop daily has always done this, especially when the air temp is cold [winter], and low revs, low - moderate load.

Anyone swapped out the coil + ignitor?

I did, didn't help. But the ignitor was a second hand one...but what are the chances of both my old one and this one being faulty???

[matt dunn]

subscribing to the thread

My silvertop daily has always done this, especially when the air temp is cold [winter], and low revs, low - moderate load.

Anyone swapped out the coil + ignitor?

I did, didn't help. But the ignitor was a second hand one...but what are the chances of both my old one and this one being faulty???

None. Toyota igniters are the most reliable ones built, never seen one fail without an external wiring issue,
yet have replaced probably 2000+ igniters over the last 15 years as an auto electrian.
So may not none, but 0/2000 = ???

[touge_ae101]

Have purchased an AE82, with a 4AGE 20v blacktop. Runs a factory 4AGE 20v computer. Engine wise, it is relatively standard (no air filter set up which I am about to change though). Previous owner last raced it many months ago and has been sitting idle since. He hasn't changed anything since then either.

It starts fine and idles sweet (maybe a little high at around 1300rom when cold). However under load - driving up a steep drive/moderate or heavy load it misses/hesitates like nothing on earth. It feels like it wants to go, but jerks heavily.

I initially thought ignition, so I have replaced:
Plugs
Leads
Dizzy cap
Rotor
oh - and a new fuel filter as last one was clogged.

After all that, it still does misses like crazy. I am now thinking possibly the coil pack, or possibly the fact that the fuel in the tank is totally sh!t house. Anything else I should look at? Is a diagnostic worth a shot to try pick up an error code?

Cheers

have you fixed this problem?

mine has gotten a lot worse now the tank is empty (to the point it will barely rev past 4k) so i'm thinking it must be the fuel pump or a very clogged filter.
does anyone have any thoughts on this?
have recently replaced; plugs, leads, oxy sensor, checked caps. only thing i haven't checked is the fuel pump and filter. was thinking of replacing the factory pump with a 500hp walbro pump and setup a swirl pot so this might be a good oppourtunity to do that as they (IMO) aren't that expensive considering.

EDIT 500hp would be a overkill. -perhaps something like this would be better; http://www.trademe.co.nz/Browse/Listing ... ermanent=0

sorry bout the thread hijack /:

[Helious]

stale petrol?

[thegreatestben]

The tank appeared to be full of 91 when we took it out last night