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Having a problem with seemingly random stalling and random bouts of rough idling in my c900. Anyone got any ideas? Have not taken it to a mechanic yet.
Bought an '87 900 16v turbo a few months ago. 126k miles, not garaged for most of its life but was in a warm climate year round. I've a ton of work to it already; new fuel pump, new fuel filter, new oxygen sensor, new plugs and wires, new coolant temp sensor, fixed wiring to the hall sensor (still an old sensor), fixed throttle position sensor, ecu is checked out and perfect, all new silicone vacuum lines, done all electric tests (in Bentley manual pg 240-20:all electric tests for the fuel injection system)-everything OK including systems relay and fuel pump relay above ECU. Other than that, I removed and bypassed the air conditioning, jumpered the wires at the air dryer, removed the cruise control and jumpered the pressure switch for the turbo. We have electrical continuity through the overboost switch for the turbo.
Problem first was that I wasn't getting power to the fuel injector plugs because there was one loose pin in the connector to the ignition control module- fixed that. Tach works, if you bang on the dash a little! Next problem we ran into was the car started and ran fine when cold, but if shut off when hot it wouldn't start up again until it had cooled down. Replaced the coolant temp sensor, seemed to fix that issue. Next problem we ran into was it was idling rough, so we checked the throttle position sensor for continuity (per Bentley manual)- couldn't get any continuity so we pried it open and cleaned the contacts inside and glued it back together and works perfectly now. (If you can't tell-not a lot of money here!)
Now, the car will sometimes idle perfectly but it stalls at complete random, as if the fuel has simply cut off. Seems like the engine turning over has nothing to do with temperature now. Sometimes it will take 3-4 tries of cranking plus a tap on the gas to get it to turn over and then it will idle rough unless I throttle it for a minute, then it begins to idle normally around 1k rpms. Other times, it starts right up and idles perfectly on the first crank. The stalling is random; doesn't matter if I have my foot on the gas or not or if I am driving or not, it will just suddenly die without warning. Drives beautifully (while its going)- I had some bucking while accelerating, but repairing the hall effect sensor appears to have fixed that.
Haven't tested the fuel pump as it's new, haven't tested the idle control valve yet, haven't tested the EGR valve. Anyone have any thoughts as to what to try? I know its a bit of a confusing situation.
posted by 64.223.132...
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