Question about 1999 Subaru Forester

2 Answers

Perfect Idle, no Codes, but stepping on gas causes hesitation

So, my 1999 forester has a perfect idle, purs like a kitten. However, if I step on the gas too rapidly, the engine hesitates to respond. I am not getting any check engine codes, so i can't say it is or isn't a sensor. I replaced all spark plugs, air filter, fuel filter, and oil change. Using 89 octane gas. The only way i can drive it is if I very slowly accelerate. If I try to accelerate too fast, it hesitates and slows down until I release the gas and apply it slowly again.

Thanks for any suggestions.

Posted by on

Ad

2 Answers

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 19 Answers

I would try cleaning mass air sensor, its mounted in air duct between air filter and throttle body, they sell the cleaner at auto parts stores, also as stated bofore make sure the intake pipe clamps are tight and it's not cracked, if that doen't fix it i would investigate a fuel pressure problem either a weak pump or problem with regulator

Posted on Feb 20, 2010

Ad
  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Subaru Master
  • 14,036 Answers

Throttle position sensor causes hesitation on acceleration.if you not getting a check light.look for vacuum leak around the air flow duct to the throttle body.

Posted on May 24, 2009

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

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

Hi,
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.
Goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

Engine will not run at idle, however it runs perfect when throttle is applied. check engine light is not on and there are no codes.


You can try to clean the throttle body.
Put new Idle air control actuator.
New air mass sensor.
New coolant temp sensor.

Jul 01, 2014 | 1999 Lincoln Town Car

1 Answer

Rough idle and hessitant when accelerating


Did you clean out spark plug wells? Sometimes when removing intake, coolant leaks into spark plug wells shorting out spark to cylinder wall instead of plug..check for coolant traces on coils.Could have weak coil.

Apr 05, 2014 | 1999 Mercury Grand Marquis

1 Answer

P0172 rich AND WONT RESET


Check for a false rich condition .. Intake leak or bad timing . If you can read fuel trim at idle and ting advance please enter the specs here and I may be able to help

Oct 24, 2013 | 2004 Honda Civic

1 Answer

87 gmc jimmy 5.7 efi intermitent miss.


You need to run a fault code test, read at the link below how to do this
http://www.obd-codes.com/faq/read-gm-2-digit-obd-codes-free.php

Apr 05, 2013 | 1987 GMC Jimmy

1 Answer

1963 vw newly rebuilt engine, starts then dies at RPM acceleration


Could be one or both of two things.

1. The accelerator pump in the carb is clogged, the linkage is unhooked, or the diaphram in the pump is bad. It's cheap to replace and comes in the carb rebuild kit. This usually just causes hesitation when you step on the gas pedal. It doesn't usually cause the engine to stop running.

2. More likely is that the main jet in the carb is clogged. At idle, high vacuum under the closed throttle plate in the carb causes fuel to flow thru the idle jet. As the throttle plate opens (as you step on the pedal), the vacuum under the plate dissipates, stopping the flow of fuel thru the idle jet, and the vacuum ABOVE the throttle plate increases, which is supposed to then draw fuel from the carb bowl thru the main jet in the carb. If the main jet is clogged with dirt, then it can idle just fine and die as soon as you step on the pedal.

Jul 24, 2011 | 2000 Volkswagen Beetle

1 Answer

My 1992 Loyale recently started acting up. The normal engine idle after warming up went from its usual 900 rpm to around 2200 rpm. The engine runs a little rough with some hesitation occasionly and is...


no
the next step is to have the fault codes read
indicates a problem idle sensor
running rich is heated oxygen sensor in the exhaust manifold or problem dirty injectors causing a problem in the air /fuel mixture settings

Sep 07, 2017 | Subaru Loyale Cars & Trucks

1 Answer

Truck want to shut off when i give it gas when running


Tough one to try to fixe over the internet... my first impression would be air leak on the intake, or a fuel pressure issue.. or even maybe a really bad air filter, youve ellimnated spark issues with good idle, and replaced everything that adjusts fuel mixture.. it sounds like a simple problem right under your nose, dont give up!!

Feb 26, 2010 | 1995 Dodge Ram

1 Answer

All of the sudden my 1999 328i started running bad idle irratic, dying ect. so i changed the fuel filter no change. i hooked up obd and got several codes. ended up replacing throttle valve,mass air...


YOU COULD HAVE DIRTY FUEL INJECTORS OR A FAULTY FUEL INJECTOR.OR YOUR GASOLINE COULD HAVE WATER IN IT.AND RESTRICTED EXHAUST LIKE MUFFLER OR CATALYTIC CONVERTER WILL CAUSE ROUGH IDLING AND STALLING.

Nov 01, 2009 | 1999 BMW 328 Series

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

1,592 people viewed this question

Ask a Question

Usually answered in minutes!

Top Subaru Experts

yadayada
yadayada

Level 3 Expert

76682 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8531 Answers

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

Answer questions

Manuals & User Guides

Loading...