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Took the mothballs out of my 87 Turbowagon but it's having some issues


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Decided to start driving my 87 Turbowagon agan (The one I got from Ed almost 10 years ago lol) since my wife's Corolla is on its last legs and I really don't want it to blow up on the freeway... 

Anyway it runs and drives ok but has almost NO power. Is fine off boost, seems to run a little better once it warms up. Will do freeway speeds (Drove it from Albany to Vancouver with no issues)but it's like the more boost builds the less power it has. I've checked fuel pressure and compression, all is in spec. Burnt off all the old gas and filled it with fresh gas. It feels like it's pulling timing, and I did get a knock sensor code ONCE several months ago, but since then nothing. Once or twice I've fired it up and it's been fine, and sometimes when I'm driving it the boost will build at higher RPM and it will go for a bit and then peter out. Check engine light came on once driving it around the block, pulled codes and got 34, 35, 42, and 51 but unfortunately since I don't work for Subaru anymore (I now do tech support lol) I don't have access to Subaru Net for repair guides, and I don't have my Subaru manuals up here. I did manage to find out what the codes meant, but no info on checking them.

 

Car is an 87, engine is out of an 88 XT Turbo, I did find a couple of vacuum diagrams (Turbo light doesn't come on, trying to figure out the "correct" routing for the lines..) and in one of them, for the 87, it shows a "knock control unit" that isn't shown in the 88 diagram, so I'm wondering if it's just a wiring issue between the 87 car and 88 engine (I'm going to feel like a real tool if it's been a damn connector in the wrong spot this whole time..) but in my searching I stumbled across a thread on here about the knock control box, and someone mentioned that the wagons only had it up to 86, was only in 87 XTs. [And of course, my brain is now trying to remember if the XT the engine came out of was an 87 or 88... Engine has a spider intake and I seem to recall them being 88+ but it's been too long LOL I'm getting old...]

 

Any help would be appreciated...

 

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How long had it been sitting? The problem may be a varathaned over carburator. I had the same problem on a bike that had been sitting, had to drive it a while before it cleaned itself out. Ask yourself these questions... Was it hard to start? Did it want to die? Would it die when you pulled up to a stop sign? If you gave it to much throttle would it spit and sputter?

 

there is also a common problem with the old turbos, one which I can't remember. I haven't had to deal with it in a long time. Had something to do with the turbos getting to hot and cracking something due to their proximity to something else. :) Sorry, great explanation, I know.

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IIRC, the separate knock controllers were only used on the Flapper-MAF MPFIs (and hidden somewhere on the left fender area, probably between fender liner and fender).  The hot-wire/later MPFIs had the knock control within the ECU.

 

Common culprits IMO are degraded high-tension parts (mine have always been touchy on spark wires), the CTS (corroded connector/wires)  and Diagnostic plug still connected.

 

The common turbo-parts failure that was mentioned is probably the upipe's turbo flange, which tends to crack:  Pretty sure that you would have heard the racket at idle.

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the turbo intake pipe might be suspect, if its leaking it will make it run and idle wrong, its very sensitive to leaks. i had to seal mine with RTV. the maf should also be checked. both those will cause the kind of problems your talking about... i know my 87 turbo wag will haul a** all the way to 110. its a snail compared to a wrx but a rocket compared to a carbed ea82

 

IIRc there are some differences between 87 and 88 something in the distributor wiring? one of the wires is in a different slot or something. maybe locate an 87 disty and try it out. I dont know exactly what the differences are but I seem to recall there being a slight difference.

 

As mentioned before the CTS is also very suspect, and pretty cheap to replace.

 

 

Hope you get it figured, I went through the same kind of low power bogging thing on mine about a year ago, first it was the CTS then the intake pipe, then the maf. it purrs like a kitten now.

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CTS definitely makes sense, I just ran down to the corner gas station to get a soda and the thing went like a bat out of hell (Still not as fast as I remember it, but didn't feel it bog down at all, and it pulled all the way to 4500 or so before I shifted), on the way back it started to bog down on me. This morning getting on SR500 it didn't want to go past like 3500RPM, but when I left my apartment it was fine. I'm getting a SLIGHT raw fuel smell when I first fire it up.. I'm gonna have to check all the hoses n crap when I get home... Any idea where the CTS is on an XT motor with a spider intake? And yeah, it needs an EJ20T lol

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... Any idea where the CTS is on an XT motor with a spider intake?...

Way down deep:  On the back side of the manifold, sticking horizontally toward the back of the engine, just a little above the block.  The connector is almost hard up against a tube...PCV crossover???

 

I had to take off my spider to get at it.

Edited by NorthWet
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So yesterday after work I decided to just unplug the CTS and see what it did.. In doing so, found the connector full of corrosion, so whether it's the culprit or not I'm going to have to replace it. With it unplugged it doesn't want to idle when it's cold (which makes sense, computer doesn't know it's cold so it's not going to give it enough fuel) but when I left work it ran like a raped ape, threw me back into the seat when I opened it up.. But once it warmed it up it started cutting out again :-\ This morning it ran worse when cold but did a little better on the freeway... I'm starting to wonder if in addition to the CTS if I don't have a bad knock sensor and a few other issues like a bad distributor cap or bad dizzy or bad plug wires :-| Guess I know what I'm tinkering with this weekend!

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Exhaust leaks in the exhaust crosspipe or at the crosspipe connections, will cause the turbo to not engage.  When the crosspipe warms up, the cracks open up.  But you should be able to hear that.  The smaller diameter crosspipes, tend to crack around the connection to the bottom of the turbo.  I believe that they come in 1 1/4" ID, 1 3/8" ID and 1 1/2" ID, as measured at the crosspipe to turbo connection.  I prefer the 1 1/2" ID pipe myself.

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It's definitely not the turbo, I have a boost gauge and it will pull 10lbs of boost no problem. Turbo spools pretty rapidly too... I think I have it narrowed down, I discovered that the fuel injector connectors on the driver's side don't have the little metal clips that hold them onto the injector. Pulling either one has almost no affect on RPM, pulling one on the passenger side kills the engine. Engine vacuum is good and steady, I'm hoping it's just a bad connection and/or a bad injector. (Makes sense, engine running lean, computer pulling timing to counter detonation, and also dumping in more fuel, which explains the 16MPG :dead:)

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