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Guest Message by DevFuse
 

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Power loss, please help.

turbo mpfi RX

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12 replies to this topic

#1 4WD Turbo RX

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Posted 10 December 2017 - 03:16 PM

I have a 1985 4wd Turbo RX manual trans Subaru.  I am not sure why I can't get the car over 4k rpm and the turbo light comes on after 3k but kinda flickers, could I get some help understanding why the cars lacks power.  I have great idle, easy cold/hot start and trouble with climbing hills and speed above 45 mph.  :(



#2 Turbone

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Posted 10 December 2017 - 03:48 PM

Look for boost leaks in all the rubber inlet hoses. If theres no leaks I suspect a bad cat



#3 4WD Turbo RX

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Posted 10 December 2017 - 04:07 PM

Ok, I have inspected for boost leaks and see nothing wrong. I thought it might be the restrictor cat but exhaust comes out strong at idle and there is no cat beyond the restrictor one on my car, it was removed with new exhaust pipe work. Is there anything that makes the car cut power that I should look into?



#4 john in KY

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Posted 10 December 2017 - 04:13 PM

Splice in a boost gauge and verify what the boost actually is. Thinking stock should be 6 pounds. I ran 12 pounds for 100K miles without any problems in my ex 90 turbo wagon. 



#5 Turbone

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Posted 10 December 2017 - 04:40 PM

May have to open up either end of the turbo to see if theres too much shaft play



#6 idosubaru

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Posted 10 December 2017 - 06:35 PM

Do 85’s have a read memory mode for the ECU? Try that.

Plugs, wires, cap and rotor?

Check ignition timing?

Check timing belts?

Edited by idosubaru, 10 December 2017 - 06:35 PM.


#7 naru

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Posted 11 December 2017 - 11:48 AM

4WD Turbo RX, on 10 Dec 2017 - 12:24, said:

 I can't get the car over 4k rpm :( 

 

Runs smooth up to 4k?

I`d say plugged exhaust.

Try it w/the downpipe loosened off or put a pressure gauge in the O2 sensor hole.

 

Your car should easily rev to 4k in neutral even with a SEIZED turbo.


Edited by naru, 11 December 2017 - 11:52 AM.


#8 jono

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Posted 11 December 2017 - 05:04 PM

I had an 85 or better known as the three plug , flapper afm Series One

 

There is two black vacuum or boost pressure actualy switches or should be, RHS tower. One drives the boost light, the other is supposedly to kill fuel or is it ignition at an over boost pressure I dont know what pressure. Maybe disconnect and see if get same problem?

 

Have you found the ECU attached to steering column? Factory anyway has a red LED you should be able to see through a peek a boo hole n under steering plastic trim panel or between it and column in the dark

 

I also got something like this from a the 20 year old coil, then again a year later on the chinese made bosch laminate style no oil can type coil. Went genuine 22433AA041 and never had problem again

 

Fuel pump[s usually cause problems just on boost as they start to fail. I would rule that out at the moment but worth checking on a pressure gauge while driving


Edited by jono, 11 December 2017 - 05:11 PM.


#9 Knucklehead Saloon

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Posted 11 December 2017 - 07:23 PM

My guess is a dirty air cleaner or a shot fuel pressure regulator.

#10 4WD Turbo RX

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Posted 14 December 2017 - 11:56 PM

The restrictor cat was plugged and problem is solved, turbo is ok and boosts again!  Thank all who helped with suggestions and info. 



#11 jono

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Posted 15 December 2017 - 01:51 AM

GO Turbine! Great suggestion.

Why does OP call it a restrictor cat?

What did you do to find it was problem?

Whadja do to fix?

#12 4WD Turbo RX

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Posted 16 December 2017 - 12:22 PM

GO Turbine! Great suggestion.

Why does OP call it a restrictor cat?

What did you do to find it was problem?

Whadja do to fix?

The car I have came with 2 catalytic converters, the first hangs vertical from the turbo and then there is a 2nd under the car just past the transmission. The 1st catalytic converter is the restrictor catalytic converter, it was plugged.



#13 skishop69

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Posted 16 December 2017 - 12:29 PM

I don't know where you got that term, but it doesn't exist. I've been a tech going on 30 years and have never heard nor read that term. Two CAT systems are primary and secondary. Glad you found the problem.







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