4AGE 20V missing

[touge_ae101]

stale petrol?

nope been driven every day for the last two weeks. always used 98 from a busy petrol station.

been tryna drive it to see if these bugs will iron themselves out so i don't have to muck round with it when there are track days i can be at.

[91 ZERO]

As Ben just mentioned ^^^, we took the tank out and was full of 91 octane so that may be part of the issue - not to mention it has been sitting for months, so could be stale too.

Pump I got was wrong (used what was listed for a 20v to match the engine). So got in a factory replacement and although not the same, could be jimmied up to fit.

From looking at the old pump, and condition of the fuel lines going to the tank - I very much doubt the pump would have ever been replaced. Will try and get the new pump installed in the next day or two - along with a healthy dose of 98 (with about 10L of fresh 100octane mixed in).

Fingers crossed.

[Dopamean]

Hate to state the obvious but stuttering while going uphill usually means you have a kink in your fuel line, if your have fresh petrol and checked the fuel pump's operation I'd get under the car and follow your fuel lines.

Have seen this before and this was the fix although not on a Toyota but goes for most makes.

Hope this is of some use....

[neo]

so been swapping out parts between my two silvertop 20v's

Ignitor + new coil (will post resistance values later) made it run slightly better (coil was slightly out of spec)

Have just swapped over the AFM, Ive been running a k&n for the past 7 years and the inside of the swapped out one was full of black oily residue (may be from the crank vent?), and the seal around the top of the afm is full of cracks

Next point of call on my list will be TPS if this doesnt help

[dnalunchie]

It's your fuel map man, you got a nasty hole it in. Well change it and adjust your Nos timing and you'll run 10's.

[MAGN1T]

Try swapping the computer.

Steve

[Crampy]

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 /:

I've got a drop in fuel pump if you want it. I'll add it to the goodies you're about to pick up if you want it. PM me and let me know if you're keen.

[BZR4AGE]

As Ben just mentioned ^^^, we took the tank out and was full of 91 octane so that may be part of the issue - not to mention it has been sitting for months, so could be stale too.

Pump I got was wrong (used what was listed for a 20v to match the engine). So got in a factory replacement and although not the same, could be jimmied up to fit.

From looking at the old pump, and condition of the fuel lines going to the tank - I very much doubt the pump would have ever been replaced. Will try and get the new pump installed in the next day or two - along with a healthy dose of 98 (with about 10L of fresh 100octane mixed in).

Fingers crossed.

Any luck with the new pump?

[91 ZERO]

Right!

I installed a new coil pack, and then we put the new fuel pump in, along with a good dose of 98 octane, and miss has gone! *touch wood*.

So, dunno if it was the fuel/pump/coil that was the issue - or all three, but for the moment, all appears to be good Appreciate everyones help, and Ben for lending a hand.

[Crampy]

That's how my mate got his BZ touring wagon going better. Filled it up with 98 and thrashed the hell out of it for a bit. Gave it a good ol' huck out.

[BZR4AGE]

Tried a new Walbro fuel pump, well that didn't solve my problem...so yea...don't know what to try next

[touge_ae101]

oh damn sorry i missed your post earlier crampy!

Tried a new Walbro fuel pump, well that didn't solve my problem...so yea...don't know what to try next

get your injectors flow tested. might even find some decent bosch injectors for high comp setups might be the go? trouble is when you up the compression, the spray pattern is adversely affected. there is quite a bit of reading about old ford engines raising the compression ratio from carbon deposits. they say if the compression is raised by 10% it will make a big difference in the atomisation of the fuel. your compression has been raised by bout 10% isn't it?

could try a set of upgraded injectors from a brand that can back it up with data sheets of how they perform at high compression. also perhaps upping the fuel rail pressure a bit might help also. of course this is not an easy fix as will require a bit of fine tuning/retune probably?

[mjrstar]

Filled it up with 98 and thrashed the hell out of it for a bit. Gave it a good ol' huck out.

Commonly known as the " Italian tune up" it works wonders on my old mini.

[frost]

oh damn sorry i missed your post earlier crampy!

Tried a new Walbro fuel pump, well that didn't solve my problem...so yea...don't know what to try next

get your injectors flow tested. might even find some decent bosch injectors for high comp setups might be the go? trouble is when you up the compression, the spray pattern is adversely affected. there is quite a bit of reading about old ford engines raising the compression ratio from carbon deposits. they say if the compression is raised by 10% it will make a big difference in the atomization of the fuel. your compression has been raised by bout 10% isn't it?

could try a set of upgraded injectors from a brand that can back it up with data sheets of how they perform at high compression. also perhaps upping the fuel rail pressure a bit might help also. of course this is not an easy fix as will require a bit of fine tuning/retune probably?

how is upping the compression going to affect the injectors?

atomization has already occurred before it gets sucked into the combustion chamber,

i could understand carbon deposits effecting swirl patterns, and maybe droplets of fuel forming because of buildup on the valve.
but even then it would warrant a overhaul clean of the valves not upgrade of injectors, the factory blacktop injectors are very big for a 1.6 already, and they like to over fuel so more injector is not going to help,

[touge_ae101]

how is upping the compression going to affect the injectors?

atomization has already occurred before it gets sucked into the combustion chamber,

ahh true didn't think that one through quite right.

not necessarily upgraded injectors but just ones with more flexible flow characteristics at lower throttle where the slutter is occuring?