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EA-81T fuel cut?


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Ok, car is an 84 GL10, has a ea82 turbo and custom exhuast, after custom exhuast the turbo lag was reduced alot, not sure if the exhuast is whats cuasing it but when i get around 4800 rpm the moter cuts out a bit, not completly cuts but cuts to the point that it kinda holds rpm and power drops quit a bit untill i shift and bring down rpm again.

 

So.......what ya'll thinkin?, fuel cut? think i might be gettin to much boost? maybe fuel pump?

 

Is it possible to override the fuel cut on these cars?, hows it done?

 

Any ideas would be very awsome as im still new to FI.

 

~Dayten~

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Sounds like this one has everyone stumped...

 

I was under the impression these motors did not have a fuel cut as a factory setup.

This same sorta thing happened to me with my EA82 T motor, it actually went away after a while, but came back, mine has trouble over 4200 rpm at the moment, right where the power is! damn it :-\

I've replaced plenty of parts and had other rebuilt etc. TPS, MAF, thermo sensor, plugs, ignition cables, coil etc etc.

I've also tried fuel from 91, 95 and 98.. no difference, but not avgas yet :grin:

 

I feel it's to do with the Knock Sensor and the Distributor/timing. But i haven't been able to pin point it yet.

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Sounds like this one has everyone stumped...

 

I was under the impression these motors did not have a fuel cut as a factory setup.

This same sorta thing happened to me with my EA82 T motor, it actually went away after a while, but came back, mine has trouble over 4200 rpm at the moment, right where the power is! damn it :-\

I've replaced plenty of parts and had other rebuilt etc. TPS, MAF, thermo sensor, plugs, ignition cables, coil etc etc.

I've also tried fuel from 91, 95 and 98.. no difference, but not avgas yet :grin:

 

I feel it's to do with the Knock Sensor and the Distributor/timing. But i haven't been able to pin point it yet.

 

Both ea81t and ea82t do have fuel cuts.... ea81t i think is just when the vaf signal gets too high..

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i would assume he's talking about the MAF, dunno tho.

 

So nobody has any takes on this problem? is there a way to remove the fuel cut?

 

im thinking that the turbo might be more efficiant with my new exhuast making it boost to much, does this sound like a possability?

 

i must say tho, the turbo spools ALOT faster now, and sounds absolutly bad rump roast!!!

 

I am also thinking about maybe replacing the vacuume plunger that controls the waste gate to see if that helps.

 

~Dayten~

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We'll wait until he answers, to see...

You could try adding a spring to your wastegate, this will help increase your boost, but then that could only make things worse if detonation is the problem causing the cut out.

I get this problem even though i'm sure it's not overboosting. I have a gauge connected, it only gets to 7.5ish PSI. Surely the cut out wouldn't happen until 12 or above?

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Ok, car is an 84 GL10, has a ea82 turbo and custom exhuast, after custom exhuast the turbo lag was reduced alot, not sure if the exhuast is whats cuasing it but when i get around 4800 rpm the moter cuts out a bit, not completly cuts but cuts to the point that it kinda holds rpm and power drops quit a bit untill i shift and bring down rpm again.

 

So.......what ya'll thinkin?, fuel cut? think i might be gettin to much boost? maybe fuel pump?

 

Is it possible to override the fuel cut on these cars?, hows it done?

 

Any ideas would be very awsome as im still new to FI.

 

~Dayten~

 

Ain`t no such thing as an EA-81T fuel cut.

Did the problem start after exhaust mods?

Sounds to me like the knock sensor is pulling back timing.

Check your dizzy centrifugal advance too(they stick).

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Ain`t no such thing as an EA-81T fuel cut.

Did the problem start after exhaust mods?

Sounds to me like the knock sensor is pulling back timing.

Check your dizzy centrifugal advance too(they stick).

 

I'd say the same thing! Granted, I still haven't messed with my car much, but I've never hit anything like a fuel cut. But thats all about to change!!!:headbang:

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  • 3 weeks later...
Sorry Ross, VAF ? whats that.

 

Volume Air Flow - The flappy door sensors like the ea81t and early ea82t uses measures air volume, as opposed to the late ea82t hot wire sensor which effectively measures mass flow rate.

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Hi chim, i had the same problem with my rx wagon at one stage..it turns out the timing was set to 0 degree,s instead of 20 btdc..and on the distributer side of the engine, the cam was advanced 1 tooth to many..i looked for days before i found these rpoblems..and once readjusted all was well again...i hope this works for you..cheers, from australia.

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Ok, car is an 84 GL10, has a ea82 turbo and custom exhuast, after custom exhuast the turbo lag was reduced alot, not sure if the exhuast is whats cuasing it but when i get around 4800 rpm the moter cuts out a bit, not completly cuts but cuts to the point that it kinda holds rpm and power drops quit a bit untill i shift and bring down rpm again.

 

So.......what ya'll thinkin?, fuel cut? think i might be gettin to much boost? maybe fuel pump?

 

Is it possible to override the fuel cut on these cars?, hows it done?

 

Any ideas would be very awsome as im still new to FI.

 

~Dayten~

 

i had a similar prob, i changed my fuel pipes, fuel filter got a bigger 1, spark plugs, air filter and spark plug cords ever since its k no prob

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  • 9 years later...

it kinda sounds like fuel cut, i hit fuel cut in my 88 supra and it would buck cut out and come back. Make sure your not running to much boost. and youre wastegate is functioning properly. these engines have a knock control system for a reason. upgrading your turbo and exhaust will increase the amount of exhaust gas flow, in return will increase the speed the hot side compresser wheel can spin, wich means way more air can be pumped into the engine. all that air without being able to compensate for fuel means that your A/F ratio will lean out at peak boost or higher rpm and the knock sensor will tell the ecu to cut fuel or spark (however this system does) to prevent pre ignition and major engine damage. this is just my basic knowlege of turbocharged engines and control systems. IF its fuel cut id say the next step is fuel, bigger injectors, fuel pump, adjustable FPR, and an vaf (vane air flow) translator or safc, to control fuel and tuning. along with afr and egt gauges so you know you arent running to lean.

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