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trubo ecu swap, now no power under boost

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Old 10-30-06, 09:36 PM
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trubo ecu swap, now no power under boost

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ok have a 89 gtu that i did a full TII swap and i was running with N/A ecu for a while and i never had any problem but i thought let me step up to a turbo ecu because im running a ticking bomb with the n/a ecu. well i hooked up the N370 ecu, the N370 pressure sensor with a FCD and the N370 AFM on N/A harness, well it run, it idle, off boost runs awsome, better that the n/a ecu but underboost it's like hitting the brakes. no power at all. it just revs hard until it see boost and just goes braaprprprpra. i have a Safc and i added up to 30% of fuel and same i put it to 0% corrections. so what could it be? could be spark plug gapping? because i have br9eix iridium with .048 in leading because i have a MSD box and .032 trailing. i just cant figure it out whats wrong. what should i check first? thanks

eddie
Old 10-30-06, 09:45 PM
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Think *Fuel Cut Defender* and installing one.
Old 10-30-06, 09:53 PM
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quote by eddierotary

well i hooked up the N370 ecu, the N370 pressure sensor with a FCD and the N370 AFM on N/A harness
Old 10-31-06, 03:02 PM
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anybody? seriuslly help me with my problem. what should i check first?
Old 10-31-06, 05:09 PM
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Look at the voltage output of the FCD when the engine cuts out and write back as to what it is.

It also has the symptoms of the secondary injectors not coming online. You might monitor the output of one of the secondary wires at the ECU when the engine goes over approx 3500 rpm AND is under a Load.

If you drive the car gently (very light throttle opening), will it go up to say, 6000-7000rpm without cutting out and acting as you described?

I trust those part numbers for the ECU etc are turbo parts. I'm not going to look 'em up.

*****i put it to 0% corrections********* I've a safc on my non turbo car, and maybe I need to play with it some more, because those words somehow don't ring right in my head....because you said you added 30 percent more fuel??????????? More fuel but 0% corrections. I need to read that SAFC manual someday.

Then again, the n/a ECU thought it was driving n/a injectors (460's) and then you put a turbo ECU in who thinks it's driving 550's. So it's delivering more fuel than when you used the n/a ECU.

Last edited by HAILERS; 10-31-06 at 05:22 PM.
Old 10-31-06, 05:16 PM
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When You Changed To The T2 Ecu Did You Get A Knock Controll Box And The Sensor? Also Did You Change Your Fuel To A T2 Fuel Pump Also What Wire Harness Are You Using Because Im Doing The Same Swap And There Are Some Things You Need To Change Like The Pressure Sensor, Send Me A Pm And I Will Hook You Up On What You Need To Do
Old 10-31-06, 08:24 PM
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you need a knock box if you don't already have one....you'd also have to wire it in to the NA harness...

I'd just find a TII harness if I were you...
Old 10-31-06, 08:52 PM
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what signal does the ecu get from the knock control box when the engine isnt knocking? IIRC it was 0 volts. So assuming the knock control box doesnt feed back a little bit of vibration from high rpm, and this in turn is used by the ecu to control fuel, not having the control box plugged in shouldnt be a problem, or even noticed by the ecu.

I dont know if this is fact, or if this is how it works, but this (and the fact that i was running the 88 vert ECU) was the reasoning behind my exclusion of the knock control box when engine-swapping. If i'm wrong, feel free to correct me.
Old 10-31-06, 09:01 PM
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Originally Posted by HAILERS
Look at the voltage output of the FCD when the engine cuts out and write back as to what it is.

It also has the symptoms of the secondary injectors not coming online. You might monitor the output of one of the secondary wires at the ECU when the engine goes over approx 3500 rpm AND is under a Load.

If you drive the car gently (very light throttle opening), will it go up to say, 6000-7000rpm without cutting out and acting as you described?

I trust those part numbers for the ECU etc are turbo parts. I'm not going to look 'em up.

*****i put it to 0% corrections********* I've a safc on my non turbo car, and maybe I need to play with it some more, because those words somehow don't ring right in my head....because you said you added 30 percent more fuel??????????? More fuel but 0% corrections. I need to read that SAFC manual someday.

Then again, the n/a ECU thought it was driving n/a injectors (460's) and then you put a turbo ECU in who thinks it's driving 550's. So it's delivering more fuel than when you used the n/a ECU.
sorry about the correction is i had it at 0 correction and i got up to +30 and still did the same thing. i actually thought about the sec injectors today because i have 680cc with resistors i dont know that would cause a problem. and about the knock sensor i heard from alot of people i dont need it with the n/a harness. i havent got up to 7k but i had it up to 4700-4800 with light throttle and wont cut off. anothe thing i notice today that my check engine light is off until it goes under boost and then it stays on all the time. i dont know if that because i dont have a knock sensor? i have 550cc primary of a turbo II. all the parts are turbo II ex the harness and the sec injector wich are 680cc with resistor. another thing i did today that i disconected the FCD and still did it. adjusted the TPS and i put the CAS on time again and no change. if is the secondary injectors how i fix it?

sorry for the incoviniece im still learning on this turbo swap and im having so much problems with it that is not funny and searching is like not finding answer of my problem. thanks

eddie
Old 10-31-06, 09:39 PM
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On a normal stock RX the secondarys will not come on line unless you reach 3800 rpm AND
the engine is under a LOAD.

So, if you don't put the engine under a load you can drive the car up into the 5-6-7000 rpm range without the secondarys coming online. Well, certainly up to 5-6000 rpm.

Using a real light foot and gradually reaching those higher rpms would constitute no load. Flooring the pedal to get there would define being under a Load.

So it seems to me, if you drive the car above 3800 rpm gently and even go to the upper rpms without your present problem, then the problem you've been having is related to the secondary injectors ocming online.

At least it should be a clue.

Maybe when you had the n/a ECU the amount of fuel coming out the secondarys wasn't as much as when you used the turbo ECU.

I don't thinik it's knock sensor related at all. I've driven without a knock sensor before for a prolonged period of time.

Maybe put 550's in the secondary spots? The 680's don't sound that much bigger though.
Old 11-01-06, 03:12 PM
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ok heres some update from today, i pulled codes out of the ecu and i have a No5, No11 and No13

5 is knock sensor
11 air temp sensor
13 pressure sensor

i dont know why all of the suddent i have codes. is theres any difference on this wires because i looked on the FSM and dont look that theres any difference
Old 11-01-06, 04:41 PM
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well heres the scoop

the pressure sensor signal wire is reading 2.24 volts with ignition on and the vacuum disconected and pluged like the FSM said that it have to be like 3.4 to 3.6

and the air temp sensor is reading 4.49 volts instead of 1-2 volts like the FSM said

my question is could one sensor could lead to the other sensor read wrong?

eddie
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