thealleyboy Posted April 13, 2011 Share Posted April 13, 2011 Hey Guys...long time... The car is a 92 Loyale sedan 1.8 SPFI; original configuration except d/r conversion. I've had some episodes where the car sputters and dies out due to fuel starvation. I've checked all the obvious things, and can verify that fuel pressure is strong at the throttle body inlet. The first time this happened, I swapped another throttle body unit. The car seemed to be ok, and I assumed that it was either the fuel pressure regulator or injector. Fast forward 4 months - same symptoms. Just for kicks, I checked the resistance of the components on the first throttle body, and they checked out. This tends to rule out the throttle body unit since the 2nd one was known to be good. Any ideas on what could be preventing the fuel from reaching the throttle? thanks, John Link to comment Share on other sites More sharing options...
Deener Posted April 13, 2011 Share Posted April 13, 2011 I had bad gas in the tank once before that caused it for me. Hows the fuel filter? Getting any blowby in the air cleaner? Perhaps the injector is dying? Just some suggestions. Link to comment Share on other sites More sharing options...
thealleyboy Posted April 13, 2011 Author Share Posted April 13, 2011 I don't think it's bad gas or filter. The car is a daily driver, so fuel gets replenished quickly. The Fuel filter was replaced when I swapped out the throttle body. I have not tested the injector in the car. Is there anything besides voltage/resistance I should be looking for at the injector? I'll definitely do these tests to rule it out when I get it in my garage. I don't know much about how the information sensors interact with the CPU, but I suspect the problem is not the injector. Any SPFI gurus reading? thanks, John Link to comment Share on other sites More sharing options...
Caboobaroo Posted April 13, 2011 Share Posted April 13, 2011 check the coolant temp sensor. It could have an affect on the driveability problem. I had a similar issue when I first put together my GL coupe and after replacing the fuel pump with a new one, I figured out the fuel injector was mostly plugged in. When the engine would warm up after driving for a bit, the connector for the injector would swell and cause it to lose connection. So make sure to double check the connections as well. Link to comment Share on other sites More sharing options...
Uberoo Posted April 13, 2011 Share Posted April 13, 2011 the fuel pump relay could be starting to die.which would intermittently kill the fuel pump. Link to comment Share on other sites More sharing options...
MilesFox Posted April 13, 2011 Share Posted April 13, 2011 fuel pump cpuld be dying? i second replacing or inspecting the CTS Link to comment Share on other sites More sharing options...
robcor2 Posted April 14, 2011 Share Posted April 14, 2011 If it ends up being the injectors.....I have a full set that was just taken off an 85 GL10 for sale. Link to comment Share on other sites More sharing options...
thealleyboy Posted April 14, 2011 Author Share Posted April 14, 2011 Appreciate all the comments... The CTS seems most likely based on what I'm experiencing, but I'll look at the other items too {again}. I'll report back when I get it nailed down thanks, John Link to comment Share on other sites More sharing options...
Deener Posted April 14, 2011 Share Posted April 14, 2011 (edited) With respect to examining the CTS, I have had two of them that were bad because I was in there around the thermostat housing messing around and in doing so I actually broke a wire off of the CTS itself, right where the two wires of the pigtail meet the metal 'nut' - but I couldn't tell it was broken because both times the rubber bit was covering it and it LOOKED and FELT like it was still attached. It wasn't until I peeled back the rubber that I discovered the disconnection. Zero resistance on the pigtail at any temperature is another symptom when there is a snapped wire. Also note - if your CTS is completely toast you should have trouble cold starting the car and it will give a very low idle (like 200-300rpms) until it warms up. Good luck! Edited April 14, 2011 by Deener More info Link to comment Share on other sites More sharing options...
thealleyboy Posted April 14, 2011 Author Share Posted April 14, 2011 Deen: Thanks for the info on CTS. I guess I have been pretty lucky to have not had many problems with Subaru SPFI. I had considered the system pretty bullit-proof until this particular car. I have had some coolant temperature swings with this car that I attributed to other factors, and maybe that is still the case. But the way you describe cold starts makes me think the CTS is definitely shot. John Link to comment Share on other sites More sharing options...
Scoobywagon Posted April 14, 2011 Share Posted April 14, 2011 You will also see this problem when the output transistors on the ECU start dieing. They work for a while, then stop when they heat up. Link to comment Share on other sites More sharing options...
thealleyboy Posted April 14, 2011 Author Share Posted April 14, 2011 You will also see this problem when the output transistors on the ECU start dieing. They work for a while, then stop when they heat up. I haven't been getting any dummy light activity. Have not tried pulling codes yet. Do you know if the burnt out resisters would trigger the check engine light? thanks, John Link to comment Share on other sites More sharing options...
Scoobywagon Posted April 15, 2011 Share Posted April 15, 2011 They're transistors, not resistors. Actually, some models use FETS and even MOSFETS. And such a failure will not necessarily throw a code. Link to comment Share on other sites More sharing options...
thealleyboy Posted April 19, 2011 Author Share Posted April 19, 2011 I replaced the coolant temp sensor several days ago, and that seemed to take care of the problem. When I changed it out I noticed that the pigtail to the harness was very short, and maybe the strain caused the contacts to fail. In any case, it seems to be ok for the moment. Thanks for comments, I wouldn't have guessed the CTS for SPFI problems. John Link to comment Share on other sites More sharing options...
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