Misfire and stuttering under load.

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Oldandslow
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Misfire and stuttering under load.

Post by Oldandslow » Sat Dec 03, 2016 5:36 pm

Hey everyone just made an account to post my question, been a lurker for a while. I'll get right to it. I have a 91 legacy ss turbo 5sp. Ever since I bought it it has had a misfire issue. The problem is if you try to give it gas too quickly, especially if its under load, it will sputter, buck, and cough through the intake. It gets worse when cold, but does it when its warmed up too. Also when cold the idle is rough and will stall occasionally. List of things I've done already, new tps, knock sensor, fuel filter, ran a ton of cleaner through fuel system, plugs, wires, tried new ecu, checked timing marks. Not sure what else it could be. If anyone has any ideas I would really appreciate it.

Alphius
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Re: Misfire and stuttering under load.

Post by Alphius » Sat Dec 03, 2016 5:53 pm

Do you have any codes set in the ECU?

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Dec 03, 2016 5:54 pm

Yes a lot but I can't seem to clear them. D check shows tps code.
1991 Legacy SS 5spd

tfoote3
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Re: Misfire and stuttering under load.

Post by tfoote3 » Sat Dec 03, 2016 6:01 pm

I would double check the knock sensor, i had very similar symptoms with mine, and i too had replaced it once before. In my case the wire to the connector for the knock sensor was trash, it had been pinched at some point and the insulation had come off the signal wire and the wire itself was frayed, i went to the JY and grabbed a long section of wire and had to get creative to splice them, but i did it, and the bucking went away.

Around that same time i had a faulty injector i didnt know about.

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Dec 03, 2016 6:04 pm

Hmm ill check the wiring. I've also heard you can relocate it? Maybe that would help?
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Tue Dec 06, 2016 7:04 pm

Welcome to the BBS.

First thing is first you need to address the codes in the ECU. What codes are stored in the ECU? Clear the codes and then check again. If d-check shows the TPS then I'd start there and check the TPS with a multi-meter.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Wed Dec 07, 2016 10:23 pm

How do I clear the codes? I connected both sets of plugs together and it didn't seem to clear. Tps seems to check out fine with the mutli meter
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Thu Dec 08, 2016 6:49 pm

Can you please list the codes that come up when you use just the black connectors connected.

When you run the d-check with only the green connectors is the TPS code the only thing that shows up? Did you check the resistance of the wiring from the TPS connector to the ECU?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Fri Dec 09, 2016 10:51 pm

When I connect the black wires almost every code is thrown. It takes a full minute and a half to cycle through them. With green connectors, yes only a tps code shows. I checked wiring even tried bypassing the wires with new wires directly to the ecu.
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Mon Dec 12, 2016 6:57 pm

Is code 35 present when you connect the black connectors?

When you connected both set of plugs, did you follow the procedure on my site for clearing the codes?

http://surrealmirage.com/subaru/engine.html#resetecu
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Fri Dec 16, 2016 9:33 pm

Yeah I think it is can't rememeber for sure. Yes I followed the procedure to a T
1991 Legacy SS 5spd

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Mon Dec 19, 2016 3:21 am

Tried pulling the fuse for ecu reset and i'm still getting all of these codes.
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Mon Dec 19, 2016 7:22 pm

Ok, so I got the following codes:

11
14
15
16
17
22
24
31
32
35
42
45
49

The chances of all those codes being a real problem are very very slim. However, you do have code 35 (canister purge solenoid) and we have seen over the years that if that code is present the ECU will sometimes not clear the codes. We believe this is because it's emissions related. So what I'd suggest you do is check the canister purge solenoid, either by checking its resistance and/or applying 12v across the solenoid to see if you can hear it click. Assuming it's bad, replace it with a working solenoid and then try the procedure again to clear the codes.

Assuming that works, drive the car and see if the problem is still there, and then pull the codes again to see what's still in the ECU memory.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Dec 24, 2016 5:41 pm

Ok thanks for the help I will check out the solenoid.
1991 Legacy SS 5spd

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Fri Jan 06, 2017 11:14 pm

Checked the resistance. It checked out within spec. So idk where to go from here.
1991 Legacy SS 5spd

mike-tracy
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Re: Misfire and stuttering under load.

Post by mike-tracy » Sat Jan 07, 2017 2:21 am

Did you also apply 12v to the terminals to see if it moves? It may be stuck closed or open despite the resistance being fine.
1992 Legacy SS 5mt, build in progress

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Jan 07, 2017 4:25 pm

No ill check that next. Does it matter which terminal receives the pos and neg?
1991 Legacy SS 5spd

mike-tracy
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Re: Misfire and stuttering under load.

Post by mike-tracy » Sat Jan 07, 2017 4:53 pm

Doesn't normally matter.
1992 Legacy SS 5mt, build in progress

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sun Jan 08, 2017 8:57 pm

Relay checks out. Probably in the wiring somewhere...
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Sun Jan 08, 2017 9:58 pm

Yeah, check the wiring out.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Jan 14, 2017 5:18 pm

Ok so I finally narrowed down the codes. I used my second ecu that was clean with no codes and ran it around. The only code that's being thrown is 32 for o2 sensor. I don't see how this could be the problem so I'm back to square 1. I'm thinking it could be the injectors, so pulled them out and tried cleaning them but there is a screen on them so there is only so much I can do. What do you guys think? Also the idle has gotten worse when cold, it won't stay running and I have to keep revving it til it warms up.
1991 Legacy SS 5spd

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Wed Jan 25, 2017 3:45 am

Anyone?
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Fri Jan 27, 2017 7:42 pm

What checks did you end up doing on the wiring?

I agree that having just an O2 sensor code shouldn't cause your problems. However, I'd suggest checking the O2 sensor wiring to see why the code might be there.

Do the symptoms get worse, better, or stay the same when the engine is cold vs. when it's warmed up?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

Oldandslow
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Re: Misfire and stuttering under load.

Post by Oldandslow » Sat Jan 28, 2017 5:47 pm

Its much worse when its cold.
1991 Legacy SS 5spd

Legacy777
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Re: Misfire and stuttering under load.

Post by Legacy777 » Sun Jan 29, 2017 4:45 am

Out of curiosity, do you know the age of the coolant temp sensor?
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
1997 Impreza OBS

If you need to get a hold of me please email me rather then pm

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