11 replies to this topic

[chuckillz]

Hello, I have a 98 forester that starts fine, idles fine, but after around 2 miles of driving starts missing and dies. I'm posting this new because i searched the Board and tried everything I could find. code says misfire on cyl 1 and 3 and the cel occasionally flashes after it starts acting up. So i changed plugs/wires, fuel filter and air filter, no change. next i swapped the coil with another running Subaru i have, no change. next i thought the injectors mite be clogged so i changed the injectors on both 1 and 3, still nothing. I'm running out of ideas so any help is greatly appreciated! The weird thing is that after sitting for awhile it will start right up and do that same roughly 2mile run(4 loops around my neighborhood) then start missing, you can watch the tac rise and fall erratically until it just dies. Whats next? Thanks!

98 forester L
156K mi
auto

[GeneralDisorder]

Try swapping out the ignitor on the firewall - about center of the engine bay, up high on the firewall. Should be a small, flat, black box with a 6 pin connector. Sounds like it might have a temp related short.

Any used ignitor from 90 to 98 (99 Legacy 2.5's also) will work. Might need the bracket as they changed shape over the years a bit.

GD

[chuckillz]

I will try that next, thanks for the tip

[Fairtax4me]

Sounds like something that is temperature related. Ignition parts tend to fail in that manner, they work fine when cold but not when warm.
Could also be a bad ECT sensor.

[unibrook]

If you have not yet replaced your front oxygen sensor, do that next.
The fact that it runs fine when cold, but acts badly when warm is your clue.

It is not hard, and your symptoms are exactly what mine were. New front 02 sensor fixed it. My experience below:

>> I have a 2001 Forester L with 85k miles on it. I have been chasing an intermittent hesitation under load problem for the past year since 80k miles. Only occurred when engine was warm. The front 02 sensor had been replaced once at 40k miles. I suspected it again this time, but since the only codes thrown had been cyl's 2&4 misfire (p0302 & p0304) I assumed it must be ignition related. So I replaced plugs and wires 8 months ago...no effect. Did the dollar bill test over exhaust pipe, it was fine. Misted the coil, no sparks. I mentally ruled out the fuel filter since it only happened when the engine was warm. Finally, a week ago while cruising on hwy at 65 mph, I felt the hesitation again (I wasn't even accelerating this time) and a new code was thrown....p0172 (bank 1 too rich). AutoZone read it for me, I described the symptoms to the guy and asked if he thought it might be the front 02 sensor. He said, "absolutely." So I decided to replace it next. Cost me $100.75 incl tax for the oem part# 22791aa00a from Cityside Subaru. I asked the Parts guy there if his experience was that this model engine needed a new front 02 sensor every 40k miles. He said, "no, these sensors are good for 100k miles." Well, bullsnot on that. I replaced the new front 02 sensor in 1 hour reaching from the top over the passenger side of the engine using an adjustable wrench. Be sure to use the thread lube so you can get it out easily next time.....after another 40k miles. I took out the air channel assembly first for better access. That seems to be the fix. No further hesitation since. Car runs like new. Replaced on 6/2/7 with 84,922 miles. (Perhaps RockAuto parts Bosch replacement sensor works well? It is cheaper) >>

Edited by unibrook, 27 January 2012 - 10:21 AM.

[davebugs]

Wow - I had a post that was lost.

I second the ignitor (although they rarely fail) they are cheap becasue they rarely go bad. If you need on I have one here.

Another thought is alternators cause weird problems on Subaru's. I usually notice the high RPM going away first. If you let the car set a little and it has a good battery it starts back up, top end is there again, then top end keeps coming down the further you drive (since youi're rally running off of the battery). Often with these weird alt problems the BAS and another light come on (not CEL or Battery ironically).

Any chain parts place wil ltest the alt for free.

And the ignitor is an easy swap.

[chuckillz]

thanks for the input guys! I'm going to start with the igniter then work my way down the list, i have a parts car so i can just swap till i find it. ill post again tonight and let you all know what happened. Any other input is greatly appreciated. thanks!

[chuckillz]

igniter was a no go, swapped it and still the same

[naru]

I would drive around the block w/a fuel pressure gauge attached.

Try unplugging the O2 sensor as well.

[davebugs]

This can also be a plugged cat - but htat gets expensive

[unibrook]

Ok, ignitor not it.
Have you replaced your front Oxygen Sensor yet?

[chuckillz]

Fixed!! It was the crank position sensor, I let it run for about 45min in the drive way and it threw the CPS code. I changed it out with another one I had lying around and it runs perfect. My mistake was that I drove the car and forced it to fail, under the load of driving it would die and just give the misfire code, just idling in the drive it gave me a P0335. FYI the crank position sensor is the same for most 90s Subaru’s 2.2, 2.5, and 2.5 sohc. The updated version has a red dot on it. Thanks for all the help guys!!! USMB is the best!!!!