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Matt, Engineer
Category: Subaru
Satisfied Customers: 20360
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
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2002 Subaru Outback, 4 cyl. 281,000 miles. New spark plugs,

Customer Question

2002 Subaru Outback, 4 cyl. 281,000 miles. New spark plugs, (this happened before changing plugs), new air filter, fairly new gas filter. On occasion, after I have driven the car for a while and it is at normal temperature, and then I stop and park the car for a short duration, like 10-15 minutes, the car will crank but not start. If I let it set for 10-20 minutes it will start right up.
Submitted: 2 months ago.
Category: Subaru
Expert:  Matt replied 2 months ago.


This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;

Airflow meter

Crank position sensor

Cam position sensor

O2 sensor

Throttle position sensor

unplug each in turn and use some switch / contact cleaner spray on the pins to ensure its all grease / dirt free

Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40

and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump

And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.

Expert:  Matt replied 2 months ago.


do you still need help?

Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you

Customer: replied 2 months ago.
I'm having a tough time rating you. Your answer was probably technically correct, but I really had no way to apply what you suggested. First I couldn't figure out which connections were the ones you were referring to, even having looked up a wiring schematic. The connections I could reach all seemed well seated, but most I was unwilling to risk detaching because they were near impossible to get my hands on, in particular the gas pump coupling, unless I could put the car on a stand or removed parts of the car to reach it. So, I really had no way to confirm the efficacy of your suggestions.In addition, the whole way this getting an answer system is screwy. I was charged $5 at the start, when I was supposed to pay only when I was satisfied - and I am ambivalent about that. I couldn't see your answer until I paid, and when I tried to pay it kept giving me an error message and that the payment could not go through. But my card is showing payment, though you are now saying yo do't get paid unless I rate you. And there seems to be no method of redress.Listen, I appreciate that this is income for you and you are probably good at it. But the mechanics of this system completely turned me off and will result in my never using it again.
Expert:  Matt replied 2 months ago.

Sorry to hear that the system didn't work out for you

probably best to request a refund