Engine bogs down

Asked by Aug 15, 2010 at 10:12 AM about the 1997 Subaru Legacy

Question type: Maintenance & Repair

I have a 97 Legacy, when friving the car after 3 or 4 miles, the engine bogs down, like one that has restricted exhaust. Mechanic has checked the back pressure, 1.2psi@2500rpm.Fuel pressure 28psiKoer volume 1pt in 10 seconds. When engine runs normally, fuel injector pulse width is 3ms @idle in park. Wehn engine bogs down, fuel injector pulse width on #1 & #2 injuctors is .5ms and #3  is 3ms @ idle. o2 sensor voltage is 0 Fuel pressure and volume are still ok. No change in any other sensor voltage while engine is bogging down. No engine DTC's stored.

2 Answers

6,225

a couple things come to mind, have you replaced all the filters yet (air, fuel, etc.)? another possibility is that the rings on your pistons or even just 1 piston are bad causing bad compression, the last thing that pops into my mind is that the rod bearings could be sticking from lack of lubrication caused by a bad oiling system or sludge in your oil. Now I don't know what all test have been run for sure because I don't know how you can simulate the conditions of driving with a load on the motor whil runing tests upon these systems you listed but I hope this helps.

85

Where are you reading fuel pressure at? Hopefully at the rails. Still sounds like a fuel filter is most likely culprit, or some other problem with the fuel system. Hell, I've had the exact same symptoms from getting bad gas, which is happening a lot more often nowadays. May even be an injector issue and sure you can check pulse width but thats just the electrical input, one may still be sticking or something. I would make sure fuel delivery is on par and find a way to test Air/Fuel ratio, find a quickie wideband tester or something :). Gotta remember, it IS a 12 year old car.

Your Answer

Add photo

Related Questions

Search Subaru Legacy Questions

Subaru Legacy Experts

#1 Anthony_60
Anthony_60
Reputation 1,240
#2 Nick Eidemiller
Nick Eidemiller
Reputation 700
#3 dandyoun
dandyoun
Reputation 680
View All

Related Models For Sale

Used Subaru Impreza
175 Great Deals out of 17,736 listings starting at $2,495
Used Subaru Forester
348 Great Deals out of 29,259 listings starting at $1,750
Used Honda Accord
822 Great Deals out of 85,700 listings starting at $988
Used Toyota Camry
1,011 Great Deals out of 90,766 listings starting at $650
Used Honda Civic
667 Great Deals out of 89,882 listings starting at $1,299
Used Nissan Altima
1,026 Great Deals out of 80,832 listings starting at $1,995
Used Toyota Corolla
763 Great Deals out of 73,024 listings starting at $1,962
Used BMW 3 Series
1,023 Great Deals out of 31,752 listings starting at $1,000
Used Acura TL
223 Great Deals out of 6,395 listings starting at $1,200
Used Audi A4
222 Great Deals out of 10,799 listings starting at $1,500

Used Cars For Sale

2017 Subaru Legacy For Sale
6 Great Deals out of 10,275 listings starting at $17,432
2016 Subaru Legacy For Sale
31 Great Deals out of 816 listings starting at $10,995
2015 Subaru Legacy For Sale
39 Great Deals out of 998 listings starting at $10,700
2014 Subaru Legacy For Sale
45 Great Deals out of 1,106 listings starting at $8,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.