jdemaris Posted February 12, 2004 Share Posted February 12, 2004 I've got a question regarding my 92 Loyale wagon with TBI. Although I've been a diesel mechanic most of my life, I don't have a comprehensive understanding on the fuel injection system used on my Subaru - and don't really want to make a research project out it. Just recently, when its cold out - like below 10 degrees F, the car won't fast-idle at start up and also is not driveable until it gets warmed up. Acts just like a carbed vehicle would when the choke stops working. I know that Chevy uses a cold-start valve and temp. sensor for this function but I don't know about Subaru and do not have a decent service manual. I looked up replacement parts at NAPA and Advance Auto, and don't see any service parts available for the Subaru injecton system that seem relevant. Any input appreciated. Quote Link to comment Share on other sites More sharing options...
WJM Posted February 12, 2004 Share Posted February 12, 2004 sounds like the ecu is reading that the engine is warm when infact its cold. that would point to a failure for the ecu's engine temp sensor...but that may not be the case. Go thru the engine bay, and clean a use di-electric grease on any and all connectors you come across and clean...that has fixed many a problems on these cars. Quote Link to comment Share on other sites More sharing options...
viceversa Posted February 12, 2004 Share Posted February 12, 2004 I don't really have a solid understanding of it either. Mine developed a weird starting problem - where it wouldn't start. Turn over ---- but not start. I tried everything. All ignition components were good. Like plugs and plug wires and dist. cap and rotor. I got so fed up with it, and tired of the car parked on the side of the road, I threw out the whole engine and put a whole other engine with its EFI stuff!!!! Easier than troubleshoting the son of a b1tch for 3 weeks. It will forever remain a mystery why it didn't work. Quote Link to comment Share on other sites More sharing options...
Skip Posted February 12, 2004 Share Posted February 12, 2004 JD since you "don't really want to make a research project out it" The FI system in your car is NOT like the one in the General Junker. There is no cold start injector to go bad. The ECU simply lengthens the duty cycle of the injector pulse width when it sees the engine is cold. as Will says. The coolant sensor may want replaced or it's connector contacts cleaned. You will find this sensor in the goose neck. It has a wired pig tail. Hope this helps Quote Link to comment Share on other sites More sharing options...
Syd Posted November 9, 2005 Share Posted November 9, 2005 The ECU simply lengthens the duty cycle of the injector pulse width when it sees the engine is cold.as Will says. The coolant sensor may want replaced or it's connector contacts cleaned. You will find this sensor in the goose neck. It has a wired pig tail. Hope this helps A friend is having this issue w/ his loyale. How can I check if the sensor is working correctly ? Also, You will find this sensor in the goose neck. It has a wired pig tail. can I have additional details about the location of the sensor ? Thanks Syd Quote Link to comment Share on other sites More sharing options...
rol1 Posted November 9, 2005 Share Posted November 9, 2005 Does the ecu dump more air in with the idle air control valve? If you're idleing good, when it warms up, does it idle faster when the airconditioner turns on? Would that indicate the IAC valve is working? Quote Link to comment Share on other sites More sharing options...
Snowman Posted November 9, 2005 Share Posted November 9, 2005 Does the ecu dump more air in with the idle air control valve? If you're idleing good, when it warms up, does it idle faster when the airconditioner turns on? Would that indicate the IAC valve is working? The ECM should kick up the idle with the A/C on. Also, it generally starts out at a higher idle speed for a couple seconds right after you start the engine, regardless of temperature. The IAC could be the problem, but I would lean more toward the coolant temp sensor, which is a common issue on the SPFI soobs. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted November 10, 2005 Share Posted November 10, 2005 the coolant sensor is the one on the thermostat housing with the green connector. the one withthe spade connector is for the gauge itself there is what is called the "idle air control" valve (skip knows this) on the throttle body that introduces a false vacuum leak to idle the engine up when cold. you can take this apart and clean it liberally with arb cleaner. its located on the front of the throttle body, the horizontal roind piece across the front the fuel injection system on subaru is very simple, the crank angle sensor is in the distributor, you have the engine temp sensor on the thermostat, and the IAC valve. thats pretty much it you can try reading the codes on the ecu, there is an led on the ecu itself, you will find it if you drop the panel under the steering column plug in the white connectors under the hood near the strut tower to read the codes you will find the ecu codes page on this website: http://www.economysuperstar.com/milesfox/subaru/service/service.htm Quote Link to comment Share on other sites More sharing options...
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