Engine bogs down when pedal is pressed

[0mk0]

Hey guys,

I have a 1998 Legacy with a 2.2 4 cylinder, fuel injected manual. Recently, my engine has been bogging down as I pressed the gas pedal. I have to let go quickly to keep it from dying. The car idles fine. I just put a new throttle position sensor on it and the problem has continued. I believe the coil pack and wires are out of spec so I plan on replacing those but I would like to know if that could be the only problem. I have a buddy who mentioned possibly having a bad fuel rail. How do I check proper operations of the fuel rail?

 

Thanks,

Paul

[OB99W]

Welcome to the forum.

 

Is the Check Engine light lit? If so, have you read any codes?

 

What prompted you to change the TPS, other than symptoms?

 

How many miles are on the engine?

 

What maintenance has been done recently? Fuel filter changed?

[Rooster2]

Welcome to the forum.

 

Is the Check Engine light lit? If so, have you read any codes?

 

What prompted you to change the TPS, other than symptoms?

 

How many miles are on the engine?

 

What maintenance has been done recently? Fuel filter changed?

 

 

2nd the vote on possible bad fuel filter. It is cheap as a do it yourself replacement. Under $10.

[0mk0]

Every one of my cylinders are misfireing. But this was happening when the car was running well. the only reason I even know about that is because the car is throwing codes. That is what prompted me to check the coil pack and wires. they are out of specs as per the Hanes manual i have but not by much. My check engine light was also throwing the TPS code. the spark plugs look great.

 

the engine has about 70,000 miles on it. the car it self has well over 100,000.

 

the only maintance I have done to the car in the past year (other than the normal oil change and breaks) was replace the nock sensor. I am sure you are all well aware of how anoying that damn thing is because of where it is located. But the car ran like a champ for about a day and a half after I had the engine backtogether.

[OB99W]

Please post all codes you're getting (P030x and any others, not the code definitions).

 

It's unlikely that you can detect a bad coil pack by "specs" (I'm assuming by that you mean resistance of the windings). Subaru uses more than one supplier for the coils, and there are measureable differences. If the two primary windings read about the same, and the two secondary windings also do, then if the resistance is close to "spec", it's probably okay.

 

What do the wires read? Have you checked for insulation breakdown? (A light misting of water after dark will allow you to see sparks if the insulation isn't holding up.) If you replace the ignition wires, be sure to use only OEM Subaru ones.

 

Based on your reply, it seems the fuel filter hasn't been changed recently -- I'd suggest considering doing that.

 

 

[...]the only maintance I have done to the car in the past year (other than the normal oil change and breaks) was replace the nock sensor. I am sure you are all well aware of how anoying that damn thing is because of where it is located. But the car ran like a champ for about a day and a half after I had the engine backtogether.

Just how much did you have apart?

[0mk0]

I do not have the codes in front of me. I'll post again when I do.

 

I was checking the resistance when testing my coil pack and wires. I was using a Hanes manual and as per the specks listed for a coil pack, mine was a little out of parameters.

 

The knock sensor on the 2.2L is under the intake manifold. The Hanes manual I was using instructed me to completely removed the entire intake manifold including the alternator and steering pump (without disconnecting the lines). Half way through I realized that I could have gotten to the knock sensor with an extension and a ratchet. To top it all off. the bolt that holds down the sensor was just loose, causing my knock sensor to throw a code and the car to sputter while driving and while coming out of first. haha. Whatever, live and learn.

 

So it sounds like the first thing I should do is replace the fuel filter. I meant to do that while I had the engine apart for the knock sensor. So I'll give it a try. I'll post the codes my soob is throwing some time tomorrow.

 

One more thing. Do you have any recommendations for online parts retailers that you trust for quick and quality parts?

Thanks for all your help.

Paul

[Olnick]

Call Jason, Parts Manager at Mike Scarff Subaru in Auburn WA--866-528-5282. Good guy. Mention USMB.

[Manarius]

One more thing. Do you have any recommendations for online parts retailers that you trust for quick and quality parts?

Thanks for all your help.

Paul

OEM or Aftermarket?

 

OEM, I use 1st Subaru Parts or Subaru Genuine Parts

 

Aftermarket, I use RockAuto

 

If the fuel filter is replaced and not the issue; I'd check Spark Plugs and wires. I don't think the coil is at issue here.

 

If those don't fix it, my next vote is MAF. When my MAF failed, it bogged pretty bad.

[ocei77]

After you've checked all the other stuff. You can think about a partially clogged cat.

 

Had similar issue with my BL. Replaced, wires,coil pack,plugs etc. Only to find that the front o2 sensor had gone, causing a lean run condition. excess fuel eventually degraded 2nd cat to where it was clogged.

 

You can check by just disconnecting header from exhaust pipe (only 3 14mm bolts). If engine revs freely after this you 've found your problem.

 

I just took section out to a shop and they had to cut the pipe, gut the cat and then reweld.

 

Wish you the best.

 

O.

[SubaruAlliance]

does it mis all the time, or only under certain conditions? i.e. when the throttle is opened half way or more, or under certain load conditions like goin up a hill, or does it just misfire all the time?

 

just asking because i had a similar problem on an 88 gl, it would mis under load, and intermittently, replacing the distributor fixed the issue and i didn't realize it till later that the cam angle sensor is built in to the disty.

 

i would check the Haynes manual for the parameters on the cam sensor and start there. keep us posted on it

[nipper]

Just lurking till the codes show up

 

[0mk0]

Hey guys, sorry it has taken so long to get back to this thread. I was away on business.

 

So here are all the codes I'm getting:

P0303-cylinder 3 misfire

p0106-Manifold absolute pressure/BARO sensor range/performance

p0122-throttle/pedal position sensor A Circuit low input

p0123-throttle/pedal position sensor A circuit high input

p0264-cylinder 2 injector circuit low

p0270-cylinder 4 injector circuit low

p0301-cylinder 1 misfire detected

p0302-cylinder 2 misfire detected

p0102-mass or volume air flow circuit low input

p0304-cylinder 4 misfire detected

p0505-idle air control system

 

So there is the list. lol. Again just to recap, all I have done is replaced the throttle position sensor. checked all spark plugs (all look great), Going to change out fuel filter and Mass air flow sensor. Car idles fine, but as soon as I touch the gas the engine boogs down. Money is short so I wanted to hear peoples opinions before I started going at every single code. Thanks for you help guys.

[OB99W]

With that many codes (and especially having both P0122 & P0123, which conflict with each other), I'd suggest clearing them (reset the ECU) and see which return. While waiting for the codes to retrigger, don't do any troubleshooting involving disconnecting sensors, etc., while the engine is running, because that will trigger codes that can be misleading.

 

You mentioned having taken the intake manifold off (or partially off? -- it wasn't clear). If it was removed, have you checked for vacuum leaks? Also, recheck any electrical connectors that were disconnected.

[Fairtax4me]

You got a vacuum leak.

There are only a handful of vacuum hoses on these engines and they are easy to check.

Be sure to also check all of the hoses for the crankcase breather system, and the Idle control valve hose, as they attach to the intake tube behind the MAF sensor (in relation to airflow). Any loose or missing hoses would create an opening for unmetered air to enter the intake tube and throw off readings from the MAF.

Poor gasket sealing can also create major vacuum leaks. There are several on the intake.

Exactly how long has the car been misfiring?

Chances are you will need a new catalytic converter to get the car 100% right after this. Misfires indicate unburned fuel is entering the exhaust system, which can overheat and damage the cat(s).

 

 

I was checking the resistance when testing my coil pack and wires. I was using a Hanes manual and as per the specks listed for a coil pack, mine was a little out of parameters.

This is negligible. If the coil were at fault it would either be open circuit or shorted, and the resistance value would likely be vastly out of range.

[nipper]

I agree with checking all the hoses first. Always look for the common denominator when you have multiple codes.

[Suba9792]

hum...sounds similar to what I'm dealing with, those knock sensors are freakin spendy!!! I just posted a thread similar, let us know what you figure out.

[nipper]

hum...sounds similar to what I'm dealing with, those knock sensors are freakin spendy!!! I just posted a thread similar, let us know what you figure out.

 

 

They shouldnt be, as you can use a generic one.

[0mk0]

lol dang knock sensor. I'm in training, so I did not see the sensor when looking for it. Manual told me to COMPLETELY removed the intake manifold (along with everything else that has to get moved out of the way) to get to the sensor. Come to find out that the single bolt holding the sensor down was just loose haha.

 

I have checked for vacuum leaks and double checked all my electrical connections. What is best way to check for leaks?

 

Typical, when ish hits the fan it really hits the fan. As soon as all this happened with my legacy my wife and I got into a serious financial situation. Now I am trying everything I can to narrow down the list before I spend the money. And wonderful New England winter is right around the corner.

[Fairtax4me]

I have checked for vacuum leaks and double checked all my electrical connections. What is best way to check for leaks?

The first way is to listen. Vacuum leaks make a hissing noise, and a major leak (which is what you have if that's the cause) will be prominent.

Use the diagram on the bottom of the hood to see where the hoses on the engine are, and where they are supposed to go. Check all the hoses for loose fit, cracks, splits, dry rot, and obviously that they are connected where they're supposed to be. Don't forget to check the brake booster hose.

 

Before you installed the intake manifold, did you make sure every last bit of the old gaskets was removed from the sealing surfaces of the manifold and heads? Did you remove the throttle body from the manifold? What about the idle air control valve?

[0mk0]

Before you installed the intake manifold, did you make sure every last bit of the old gaskets was removed from the sealing surfaces of the manifold and heads? Did you remove the throttle body from the manifold? What about the idle air control valve?

 

I did make sure that all of the old gasket was gone. I used a straight edge to ensure that she was nice and smooth. and no i did not remove the throttle body from the manifold. I will take a listen tomorrow evening and let you know what I find. thanks.

[0mk0]

checked the intake manifold gasket again, it looks and sounds good. I went to check the volts going to the MAF but as soon as I pulled off the connector, the engine started sputtering and got ready to die. that tells me that the MAF is getting power. The wire harness going to the MAF is a three prong plug. Tested that for volts and got just about 12.

 

ok so while I was looking I found a T connector that joins three vacuum hoses. problem is that one of the vacuum hoses is missing. when i pulled the intake manifold off I labeled EVERYTHING. and anything that came out went right back in. plus there were not any lines that I had to take completely off. I was at least able to keep one side attached with each hose. so I have no idea if there was a missing hose there before I did my work. the hoses are directly under the right side of the intake manifold. If someone can explain to me how to attach pictures to this thread I will so you guys can see exactly what I am talking about.

[playtimeover]

Hi Rooster2. I agree with. Very very agree.

[OB99W]

[...]ok so while I was looking I found a T connector that joins three vacuum hoses. problem is that one of the vacuum hoses is missing.[...]

How does what you have compare with the label on the underside of the hood?

 

 

If someone can explain to me how to attach pictures to this thread I will so you guys can see exactly what I am talking about.

Unless they're small, host them on another site and provide links.

[johnceggleston]

ok so while I was looking I found a T connector that joins three vacuum hoses. problem is that one of the vacuum hoses is missing.

 

 

one of the lines from the t goes to the passenger strut tower and has a small gray? cylinder inline. it feeds 2 doodads bolted on the strut tower.

 

one of the other lines goes down under the intake and i think it connects up to the charcoal canister in the rear by way of a small metal line that runs under the intake . it feeds in on the driver side with next to the fuel line, pretty sure.

 

the 3rd leg of the t comes up and IIRC it connects to a nipple on the side of the intake, or maybe the throttle body.

 

so which line are you missing??

 

the one going to the strut tower should be pretty obvious. i would look for the one under the intake it's probably only a few inches long like the top line.

 

i have used windshield wiper fluid line to replace lost or cut vac lines. i don't know if that is a no-no.

Edited November 6, 2010 by johnceggleston

[WoodsWagon]

Vacuum leaks will cause the greatest issues at idle, under load they don't factor in much.

 

That many codes means you either turned the key on with a bunch of sensors unplugged or you have a ground issue. I'm betting you had a bunch of stuff unplugged and most of those codes won't come back.

 

If it completely falls on it's face when you try to accelarate, you either have a faulty knock sensor causing the ECU to pull all the timing, or you have low fuel pressure.

 

Fuel pumps are easy to get to, there's an access panel in the back.

 

Plum a fuel pressure gauge into the hoses between the fuel filter and the engine. Read the pressure with it idling. Then remove the vacuum hose from the fuel pressure regulator on the rear passenger side of the engine, the pressure should jump up a few pounds. Re hook that line, then use a pair of pliers to gently clamp down on the return line going back parallel to the feed line you tapped into for the gauge. The pressure should really spike up if you do that.

 

I've seen fuel pumps that could only muster 20psi, enough to idle, but not accelerate.