I recently reacquired my old 1989 GL10. Had the car 07-08, replaced the turbo, all the seals, swapped in a dual range 5 speed, and had it running pretty good. Sold it to a friend, she drove it about 15k miles till it spun a CV shaft in a hub. I bought it back cheap. It has been sitting about a year. Got it running, got it home, fixed the hub, drove it to work. It has no power under load/boost situations. Like 55mph in 3rd on the hills. If i crack the throttle it will accel, slowly, but more throttle it falls off. Lower speeds it stutters while trying to accelerate.

So far i have welded up the cracked header pipe, thought maybe the exhaust leak was bad enough to be loosing boost. That made it worse. But a new filter on it, and some injector cleaner. Checked the turbo. Spins nice, turbo light comes on. Visually checked the MAF. Set the timing to 20 with the green plug connected. Checked fuel pressure. 30-40psi depending on vacuum, engine side of filter, 65psi with the return line pinched. Test drove it again. No change. Its making boost, popped the intake off the TB. When it did it, the turbo was so hot it was bright orange. Now, i work on diesel trucks, and have seen my share of glowing turbos, but this was looking like you could push a screwdriver though it. Im guessing with that sort of EGT its going lean. SO now im looking for advice from the guys that know subarus as where to look next.

Problems under boost are usually ignition related. The higher load stresses the ignition system and if the spark plugs, wires, cap, rotor or coil are marginal they won't reliably fire. Having a large amount of unburned fuel in the exhaust could maybe heat the turbo up more, but that almost sounds like a clogged exhaust. But then you wouldn't be building boost, so I'd be back to ignition issues.

It sat for a good while. I'd be looking the fuel system over real close. Check the injectors as yea, it sounds lean. Look at the fuel and filters close.

 

Doug

Edited November 26, 200916 yr by Quidam

Brand new plugs, Wires, cap, rotor have about 18k on them. Cap and rotor looked great. I replaced everything before I had sold it. Brand new fuel filter. Full tank of fresh gas. Good fuel pressure, not checked under load though, IE, 30-40psi from idle to 5500 rpm in neutral.

Oh, and fuel burn is very uneven from side to side. I drove it to work the first day, pulled the header off to weld it up at lunch, left bank exhaust was black, rich, right bank was white. The plugs that i pulled looked great. So i assume it is something that has come with sitting. And one code for idle swicth.

Injectors possibly. Vacuum lines, are they rock hard and cracked?

 

Doug

Edited November 26, 200916 yr by Quidam

Just replaced the PCV hoses, and have checked every vacuum line. It idles great and runs smooth all the way up, except under load. I'm gonna do some more checks of ignition.

So I may have found it. I should know better, but ive been working in the dark till today, literally. I started checking the wires at the cap...one of them was completely corroded....going to number one, the bank that was rich when i pulled the exhaust. Then i pulled the coil wire at the coil, its bleeding oil good. The hole boot was full. So I'll try new wires, cap, rotor, and I think i have a coil to try. And report back.

Cool.

My 87 GL turbo does the same thing, except it doesn't like to idle unless I clamp the fuel return hose off with a pair of vise grips. I've had no luck finding a fuel pump for it though

So I may have found it. I should know better, but ive been working in the dark till today, literally. I started checking the wires at the cap...one of them was completely corroded....going to number one, the bank that was rich when i pulled the exhaust. Then i pulled the coil wire at the coil, its bleeding oil good. The hole boot was full. So I'll try new wires, cap, rotor, and I think i have a coil to try. And report back.

 

good!

 

if that doesn't work check all your injector clips for corrosion.

"I've had no luck finding a fuel pump for it though :("

 

Explain please. Thank you.

 

Doug

New cap, rotor, wires, and a used coil I knew to be good, reset the timing to 20, only a marginal improvement. Checked injector plugs...one was corroded a bit. cleaned it and tightened the connection. No improvement. Rigged up a gauge I had to check boost. 7psi with the gauge leaking a bit.

The car starts great. Idles great. Runs smooth. And decent on flat ground. As soon as I hit a hill on the freeway its down to 3rd gear, 50-55mph. Falls completly off at about 5000rpm, wont pull past even on flat ground. Almost feels like cam timing is off. Or not advancing. Have a dirt bike that ran just like it. Ran great. pulled ok, just no power on the top end. Found my cam timing a tooth off. Not sure how a subi would run with cam timing off a tooth? So many possibilities.

Check for exhaust restrictions, a clogged or melted down converter will cause all of your symptoms.

I know it can, but would it still make full boost with the exhaust plugged? And i get lots of exhaust pressure out the back, and bottom and side, of the muffler..lol

Problem Solved! Chased a few more things, checked cam timing, everything looked great. Retensioned the timing belts, and went to check the timing, again, just to be sure...It was about 2 degrees! Reset it, and it runs great. I think what happened was last night i pulled the TPS off and tested it, and reset it. I dont think it was getting the idle switch signal, and i rememeber reading somewhere the computer needs to see that along with the green plugs conected to set the timing.

" Retensioned the timing belts, and went to check the timing, again, just to be sure...It was about 2 degrees! Reset it, and it runs great."

 

But...did you even touch the tps, between tightening the belts and when you checked the timing?

 

Doug

No. Not between tightening the belts and setting the timing. But I doubt the belts were off enough to change the timing 18 degrees. They only had about 15k on them. But the idle switch was not closing before i messed with the TPS. And last time i checked the timing, it was the same with or without the green plug connected.

ok im lost here but i think my issue may be related. can we explain this whole thing a bit more indepth so i can understand whats going on that might be my car's issue