1991 9000 Turbo starting/idling/running issue

[Turbo 9K]

So Ive been trying to get my old beast back on the road, stopped driving it a year ago when it developed this problem since I didnt have time to deal with it.

I was racing a friend, during third gear something happened under full boost, it started hesitating under certain loads, and working under different loads. Was not able to idle on its own.

It starts but immediately dies if you do not input some throttle to keep it running. If you quickly jab the throttle it will act like its dying for a sec then catch again and rev up. It will rev somewhat smoothly if you give it slow throttle inputs. And will not idle on its own.

I will post some video of what its doing tomorrow if it helps to understand the issue.

Seemed like a fuel issue. Replaced pump, issue remains. I broke the return check valve while removing it so I drilled out a supply valve and am using that as an unchecked elbow basically, I dont think it should matter since it will always be flowing back to the tank, anyone disagree?

I also replaced the DIC with a spare just in case and problem is unchanged.

Since problem occurred immediately under full boost (modified 9000 with bigger turbo, 300whp), and not gradually Im now leaning towards it being a vacuum/boost leak issue. My new gameplan is to go over all the vac lines and charge pipes. I cant think of anything else unless anyone has a suggestion.. Help me get her back on the road!

[sp53]

Yes I would suggest looking around the throttle body for a blown out pipe. The one on the bottom of the throttle body itself often pops the brass fitting off.

[jw.roberts]

be sure to check mass air flow. if computer doesn't know how much air is passing it doesn't know how much fuel to deliver. I've seen many people replace part after part in fuel and exhaust systems when problem is faulty MAF

[WarGames]

Awesome setup I like the sweedish flag and the intercooler cutout!!

I don't know if the '91 has the same turbo setup as the '93, I think they are both DI/APC (not T5).

Although there are surely some differences between the '91 and the '93 turbo hose setup, you may try replacing the Safety Runoff Valve (TCS) if you have a TCS setup but I'm assuming you don't (i dont even know if they had TCS for the '91s)?

Both my '93 saabs have TCS/Electronic Throttle so if this doesn't apply to you just disregard.

http://www.eeuroparts.com/Parts/Part...rtCode=4015202

If you do have TCS, buy the part from eeuroparts not the dealership, you'll save yourself a nice 400 bucks.


My Last 2 Cents:
Techron Fuel System Cleaner does wonders for throttle body / idling / boost issues, sometimes it takes 2 doses for it to really work. Also check all vacuum lines, solenoids, valves etc. for leaks and failures. Good luck!