Question about 1999 Subaru Legacy

1 Answer

Subaru 1993 legacy rough start with backfire/missfire.

Once it runs for a bit it is fine,, but it is hard to start. I cleaned the fuel injectors but had no luck. I am thinking it might be a fuel filter or oxigen sensor.

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.


    An expert that got 20 achievements.


    An expert that got 10 achievements.

  • Subaru Master
  • 75,744 Answers

O2 sensors do not cause any kind of starting problems, what can is a dirty upper intake and loss of fuel pressure after the pump turns off.
Here is what I would like you to do, run a fuel pressure leak-down test on the system, to do this you will need a fuel pressure tester, this connects to the fuel pressure test port that is in the fuel supply rail that connects to the fuel injectors, it looks like a metal tire valve, the tester is about $15 at any Kragen or store like it, hook the tester up and verify no leaks, then run the engine and make a note of the fuel pressure reading, shut it of nd let it sit, the pressure should not drop more than 5 PSI overnight, if it does the fuel pump is defective as the check valve in the pump has failed, this allows fuel to drain back to the tank and creates a lean condition when the car is 1st started, result, rough running, long cranking times..

Posted on Apr 17, 2009

  • yadayada
    yadayada Apr 17, 2009

    also do the following:

    Here are some of the causes of surges, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Why does my 98 subaru legacy sputter and die?

Clean your MAF sensor and throttle body. If it's dirty it will send wrong voltage to ECU, running either too lean or too rich, most likely too rich and flooded the fuel injectors.

Aug 25, 2014 | 1998 Subaru Legacy

1 Answer

Car starts and runs ok......after it warmed up and you restart, runs rough, but will clear up by giving gas making it idle faster

What is the vehicle - especially the age. There are many things that can cause this and age has a bit to do with it.

Let me know - it will make it easier to answer.

Aug 03, 2014 | 1999 Subaru Legacy

3 Answers

Starts and runs fine.....rough runs, when you restart after warmed up

Sorry - I didn't see the vehicle information the first time.

Let me research this - i will get back to you soon.

Aug 03, 2014 | 1999 Subaru Legacy

1 Answer

1992 Lumina Backfire - I have a 1992 Lumina Euro, 77K miles, 3.1 V-6. Under moderate to hard acceleration the engine will backfire and you can smell gas. The spark control module, coils, wires, plugs,...

I know you mentioned the EGR valve has been replaced, but you may have a bad 'new' part. I know the car is electronic, but has anyone checked its ignition timing (timing belt been looked at, I know it only has 77k on it). Is the fuel pressure regulator OK and it vacumm supply?

Nov 15, 2010 | Chevrolet Lumina APV Cars & Trucks

1 Answer

I have a 1992 subaru legacy. The last two weeks the car takes awhile to get started, only happens on the first start of the day..starts fine after that...It takes a couple of times to get it...

I think it may need to be tuned up. When it is warm it doesn't do this I gather, even a little bit warm.

Could also be a fuel delivery problem. hm.

Jul 04, 2010 | 1994 Subaru Legacy Outdoor

1 Answer


The cylinders are numbered as on the spark pack you changed. You might have done better putting the seafoam in the tank as an injector cleaner. Not sure why you changed so many parts, you seem to know how to get the codes from test connector lead hookup and the blink pattern. You might also want to check the fuel rail pressure and the crank and cam angle sensors. Before replacing the injector, swap the #4 injector with the adjacent one and see it the code moves with the injector or stays put. If the code stays on #4, then check the injector wiring, if it moves clean or replace the injector.

Mar 16, 2009 | 1991 Subaru Legacy

2 Answers

Subaru problem

Have you checked if you have ignition on the spark plugs leads? Is petrol coming to the injectors?

Aug 24, 2008 | 1993 Subaru Legacy

Not finding what you are looking for?
1999 Subaru Legacy Logo

894 people viewed this question

Ask a Question

Usually answered in minutes!

Top Subaru Experts


Level 3 Expert

75744 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22114 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8123 Answers

Are you a Subaru Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides