[eteran4]

Been having some idling and starting issues for about 1 1/2 months now but its not consistent. When idling my RPM's slightly bounce around. Not aggressively but enough to notice it. It bounces around anywhere between 500 RPM and 800 RPM. On two or three occasions my car almost stalled when coming to a stop but never did and that would only last for a couple miles until started running normal again.

The staring is issue is even less consistent. On 4 or 5 occasions my car will have trouble starting up. It'll turn over and eventually die all within a few seconds. But with just some gas while turning it on the problem will go away until it mysteriously comes back again.

With all that being said I have changed my spark plugs and wire, my air filter, and my gas filter. I also cleaned my IAC valve and checked for vacuum leaks. After all that no improvement. My best guesses are that it can be the IAC valve might shot, my fuel injectors are clogged or not working , or I need a new coil pack. If you have experienced similar issues and found a solution please let me know. I don't want blindly change expensive parts. Also if it helps my MPG is seriously suffering.

 

[2.5x_sleeper]

I see this is your first forum post, so welcome to the forum from Oregon! :biggrin:

Do you have a lit CEL? If so, what codes are stored?

Take a look at this thread to see if your symptoms are similar: Neutral Switch

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]

 

[eteran4]

Thanks for response and thread! I will look into it.

I did have a code about 3 weeks ago but for an o2 sensor and got that fixed right away. Changing the o2 sensor didn't help with my current problems unfortunately. I also checked for any stored codes and didn't find anything.

Also, I don't know if this has to do at all with my current problems but I noticed about a week ago that my head lights will not turn off unless the car is in park. Once I put into any other gear my lights will turn on regardless of the if I have my lights set to off. My dash board lights illuminate all the speedometer/gas/ ect. seem to slightly flicker. Not on and off them dim and brighten just slightly. And my horn seems to be a little weaker. I had my battery tester and check some fuses but everything looks fine. Again I don't know if this has anything to do with my engine performance or if its a whole other electrical problem in itself. Just thought I should throw that out there.

Manny.

 

[leland grant]

electric system problem will do all of that , weak battery, weak charging system or excess draw/short, all of the power for start/ run systems flows thru the start ignition key circuit, it is known to go out look for corrosion at plug joints connections, cable to battery , bad ground subarus tend tio have bad ground and weak systems as far as electric

 

[eteran4]

I will look into that as far the electrical problem is concerned, thanks!

 

[mikec03]

For sure, get a wrench and make sure that the battery connections and grounds are very tight. Everyone should do this occasionally.

You have the 251 engine, the same as I do. It doesn't have an MAF, just to forestall comments blaming that. With my car, the problem with the idle "hunting" was the upstream O2 sensor. So that brings up the question: Which O2 sensor did you change and what was the exact code that caused you to change it.

 

[eteran4]

So I had the code for the Upstream O2 sensor but changed both since they had the same amount miles on them. I don't know the exact code but I do know for sure it was the upstream. Changing the O2 sensor didn't really make a difference other than not having a check engine light.

 

[eteran4]

I just tested my coil pack and it seems to be working as it should. So now my best guesses are the IAC valve, fuel injectors, throttle body (might need cleaning) or even the fuel pump might be going out.

Had some more trouble starting it up again. It was doing the same thing; it would turn on then die almost immediately and had some shaking. It started going after giving it some gas. I was about to head out of town with until that happened. After contemplating for while i risked it anyways and took for a 190 mile drive and frankly she drove like a champ. That being said, it goes to show how inconsistent my problems are. If anyone has any idea on whats going with car or is experiencing any similar problems please help me out. I having a serious love-hate relationship with this car right now.

 

[2.5x_sleeper]

So I had the code for the Upstream O2 sensor but changed both since they had the same amount miles on them.

Did you replace those with Denso factory/OEM or Denso OEM fit O2 sensors?

It was doing the same thing; it would turn on then die almost immediately and had some shaking.

Was the CEL flashing when this was happening?

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]

 

[eteran4]

Still no CEL...

 

[eteran4]

Has anyone used fuel injector cleaner for there car ? If so would you recommend it?

 

[2.5x_sleeper]

Normally, if you use a good grade of gas, you don't need to use fuel injector cleaner. It's not going to hurt anything if you want to add that to your fuel. :wink:

Bobby...

['07 FSXT MODding Journal] ['03 X MODding Journal]

 

[gathermewool]

Did you replace those with Denso factory/OEM or Denso OEM fit O2 sensors?


Was the CEL flashing when this was happening?

Bobby...

+1 to both questions

Do you have similar problems regardless of fuel tank level?

 

[eteran4]

I replaced them with the Denso factory/OEM .

No flashing or solid CEL.

The fuel level doesn't seem to make a difference. One time the problem occurred right after I topped the tank, and other times has happened at half tank or quarter tank. Seems completely random to me.

 

[eteran4]

Hello again,

So I used Lucas High Mileage fuel system cleaner this past Sunday. Since then I have not had issues starting the car or idle problems. I have driven about 200 miles total since then and no problems. It might be too soon to tell if my fuel system is where my problem truly is (since my problems don't happen regularly) but if it is do you guys recommend getting a more detailed cleaning now like cleaning my fuel injectors or maybe switching to better quality gas. Or should I just wait until something happens.

Manny

 

[Kevin]

With thanks to TassisAs for drawing it to my attention (via email) you may want to check out this thread if the issue returns:
https://www.subaruforester.org/vbul...e-money-solved-784477/index2.html#post7443379

 

[eteran4]

Thanks for that thread. Gives me a lot to think about.

Unfortunately the starting problem came but I think I may have found a way to replicate the problem. Yesterday after I had just parked the car after getting home from work I accidentally hit my remote start button to turn the car on and the car started, sputtered then died. It also made loud "popping" sounds from the engine. I didn't try turning it with the remote again but instead with the key the second time. It did the same thing, started, sputter then die but without the popping noise. I did that a couple time until it started when I gave it gas. I drove it around for 5 or so miles (It drove fine). When I got home I turned it off and then on. It started as it should. I then waited a couple of hours and went back to turn it on and it started just fine. This morning it also started just fine.

To me it seems that the remote starter might have triggered something that is caused my starting issues to happen again but honesty I am too afraid to try again since its my only source of transportation. A little background for the remote starter: It is an after market part that was added before I bought the car. I rarely use it because I honestly see no point in it. Last time I used it was about 4 months ago and it worked fine.

I don't know if my remote starter has anything to do with my problems I am experiencing but I plan to take it into the shop to see if I can replicate the problem with my mechanic. I also plan on getting a fuel pressure test.

If any of you have any similar problems please let me know on how you fixed it.

Manny