Date: Mon, 8 Mar 1999 08:19:53 -0500 From: "Eric Law" <elawnopsamexxx.com> Subject: '86 9000 driveability problem (long)
OK, so here's a tough one. I've got an '86 9000 turbo 5-speed with a subtle driveability problem that's driving me nuts. Basically, the car "hiccups" when you go from off- to on-the-throttle. Example: you're coasting toward a red traffic light w/foot off the gas. Light turns green and you step on the gas to accelerate. Before making power, the motor seems to "cut out", just for a small fraction of a second. Then it accelerates fine - runs absolutely perfect otherwise. Only time it doesn't do this is when the motor is cold. Could this be characteristic of all 9000 turbos? I've never driven another with a 5-speed. I've driven automatics, they don't do it. I've driven (many) 900's, and they don't do it either. Here's what I've checked: All tune-up items have been replaced (plugs (Bosch platinum), wires, cap/rotor, fuel & air filters). Timing OK (tried advancing and retarding, no effect). Swapped FI computer (seemed to make a difference, but small enough it could have been the weather). O2 sensor tests OK, haven't tried replacing it. Inspected all hoses, etc. in intake system, tightened clamps, etc. All vacuum leaks fixed. Turbo bypass valve replaced (was bad when I bought the car). Crankcase-ventilation check-valve (the small grey one) replaced. Throttle switch replaced (this seemed to eliminate about 1/3 of the problem). Swapped idle-control valve. New throttle cable. Adjusted throttle-stop screw by factory procedure. Tried disconnecting charcoal canister (and plugging lines) - no effect. Oil/filter are kept changed (Mobil 1), valves are not noisy. Turbocharger is OK (rebuilt just before I bought the car 2 years ago). Anyone have any other ideas? Eric Law
