4agze running very rich / fouling plugs

[Necros]

Hey Guys,

I've just got my 4a-gte running using a series II 4agze (afm + cas). I have removed all of the gze solonoids and s/c. I am running a cut/shut fwd 4age intake w/ a vn commodore 65mm throttle body. No idle control valve is installed as the vn one is not compatible. Also I have not yet installed the single wire exhaust ox sensor.

At idle the mixture is very rich and black smoke is noticable from the exhaust. The plugs have already fouled once (I.E. wouldnt fire at all). The idle is also quite lumpy and searches +/- 200rpm. When driving I need to ride the clutch to about 3000rpm to get any power...

Why would the mixture be sooo rich (obiosly the ox sensor wont help being disconnected)?

What can I do to fix this?

Also do I need the FPU solonoid? Currently the FPR vac line is connected to the intake manifold.

[bansheebuzz]

you have changed too many things for it to ever run correctly on a standard ecu and thats my thoughts to its poor running

[Cameron_Datto]

Have you ever had it running correctly ?
As Bansheebuzz has said you have changed a lot of things , If it was just a standard engine set up , things i would be looking at would be ,

make sure your Air flow meter flap isnt jamming inside or some one has played with the spring tension ,

check the water temp sensor for the correct water temp signal ,could be reading a extremely cold ,

fuel pressure to high or return line blocked ,or diaphram cracked on fuel pressure reg and fuel going into vacuum hose on manifold .

wrong sized injectors , wrong model ecu for engine

make sure your battery is ok and you have a earth cable on the engine .

[Necros]

The engine has always been running too rich, since I've had it...

How can I check the water temp sensor? What sort of reading should I have on a normal 20deg day with the engine cold?

As I said I've connected the fuel presure regulator vac hose directly to the intake manifold and am not running the original 4agze vac lines/solonoids. How is the 4agze FPR meant to be plumbed for vac?

[BeRad]

adding a turbo to a afm that wasnt designed for it doesnt work, because even when youve backed off the turbo is still spinning therefore pushing air through the sensor. And it makes it run stupidly rich, the same happened to me when i thought id try run a stock ecu with the boosted 3rz, it just doesnt work...

[Necros]

BeRad,

But how would this cause the engine to run super rich on idle? With no revving/backing off...

[BeRad]

the turbos still spinning, so its going to alter the readings somewhat when the ecu wasnt tuned to interprut more air flow on idle, im not sure weather the afm would pick up that slightly extra air but it seems to alter it somehow, the exact same thing happened when i turboed my hilux, i was always goin aftermarket but just wanted to see if i could get away with running stock for a few months.


when you back off the afm has already read shitloads of air coming in when you back off the throttle body closes and that air is then thrown back out the turbo. so the ecu has allowed that much fuel to go in at that point but you have not used the air so it has over compensated in fuel mixtures.


the o2 sensor would make a big difference also not being connected, but i dont think it will solve the whole problem.

if i remember correctly haha its been a while since ive played with my fpr, but the hose sould be connected before the throttle body, in one of the nippled on the actual unit not into the plenum. have you got a guage hooked up to the fpr? if so its easy to work out set the fpr by turning the car onto on, the fuel pump will fire up the guage will then read the set pressure when you start the car the pressure should drop, if it doesnt it is hooked up wrong, when you rev the engine it will come back up to the set pressure when it reaches atmo pressure, when it comes on boost it will lift above the set pressure.

[kingmick]

you computer is running in WOT{wide open throttle} mode as the ECU knows there is a problem!
God the PM was a waste of time.

[BeRad]

haha, well there ya go.

[Necros]

you computer is running in WOT{wide open throttle} mode as the ECU knows there is a problem!
God the PM was a waste of time.

Well if I could work out exactly what is causing the WOT mode then maybe I can go about trying to fix it? So no your pm wasn't pointless, it just didn't give me anything to go on...

[kingmick]

I dont see a way you are going to get that setup to work with the factory ecu, you asking way to much of it!

[Necros]

Hmmm, it's all just not what I really want to hear yet... Having read of so many 4a-gte's I didn't see how it all would go so pear shapped... Am I really the only person to turbo an afm 4agze?

I guess it's time to start shopping, again...

[Hen]

Necros, I think your setup SHOULD work. I really don't see why it matters whether the engine is SC or turbo, it should meter the air and inject roughly the right amount of fuel.

Do the usual stuff, check for error codes from the ECU and clear them if needed, check fuel pressure and check injectors are working properly.

If you think it's at WOT all the time, check the WOT pin on the ECU while the engine is running and see if it is high. You could also check the TPS signal and ensure it is working right as you move the throttle.

Hen

[sideshow]

just save up and buy an aftemarket ecu

no matter what u do with std ecu it wil be shit and not 100%

my theory is do it propelry or dont do it at all

your just wasting your time

making good power costs money

even if u do get it half right you might be wasting fuel
if u waste a coupe hundred bucks of fuel in a year

thats more money ou could have put towards a microtech or something

cant believe people are actually tryin to help a useless casue

anyway just m,y 2 cents

fit the o2 sensor see if it helps abit

water temp wire at ecu should have about 3vlts when cold

then come down to around 1 or .8 volts when warmed up

try unpluugin the water temp sensor see if it makes any changes

but like i said at start no matter what u do you wont get the full potential

and can end up fuking the engine if mixtures are not right and you keep thrashing the car

you could tryremove cover off airflow meter and mark the position of flap tensioner spring or gear then back it off afew teeth and see what happens only prob is if you back tension off airflow it will open quicker when u accelerate so u might cause more problems

i would try sell the 4agze wiring loom and std ecu then put money towards a microtech

have you checked cas timing

block all vac hoses etc

[Sprinter]

You dont happen to have the cold start injector wired in by any chance?

I am running a MAP/DLI 4AGTE with OEM ECU and was having issues with the mixture with this plugged in (its still rich but nowhere near as bad). Similarly, it will dump more fuel in Open Loop mode which will happen without the O2 sensor.

Just MHO