Backfire?

THAWA · Post by **THAWA** » Sun Mar 14, 2004 4:53 am

This just started happening today, after the car was warmed up and while idling the revs would stumble and drop a few times, it felt almost like how it felt when my IAC was stuck, but more violently. The whole car was shaking at one point. Then when I went to accellerate it felt like I had no power and I would hear a pop, sometimes I would hear it from the driver side and sometimes from the pass side, but it was always near the front. It only happened when I had been idling like at a stoplight for more than about 10-20 seconds. and the poping would only happen when I woudl accellerate after the revs stumbled like that. If I was just driving it would be fine, it would accell just like regular(which isn't all that great, minor hesitation). The only thing I've done since yesterday was remove the heatshield from the midpipe. It didn't do this yesterday after the heatshield was removed so I dunno. I checked for codes and all taht was in there was 13(still haven't cleared it since I was having problems with that bolt) So yeah, anyone know what coul dbe up?

vrg3 · Post by **vrg3** » Sun Mar 14, 2004 4:57 am

I think the backfire is probably a result of the stumbling... You're misfiring for some reason and then when you take off the excess fuel is igniting outside the combustion chamber.

So... Why does the engine stumble at idle? It could be as simple as a bad tank of gas. Maybe you should siphon it out and fill up with fresh good gas and a bottle of Techron injector cleaner or a little Sea Foam and see if it goes away. Always good for your car anyway.

If the problem appeared suddenly I would first suspect bad fuel or maybe a vacuum leak that just appeared.

THAWA · Post by **THAWA** » Sun Mar 14, 2004 5:03 am

I had suspected gas as the culprit, or lack of it I should say, so I filled the tank today(was almost empty) but no good. techron you say? I do have some sea foam left over, but last time that didn't do much for it. I'll prolly try it again anyway. I wouldn't doubt the vacuum leak crap, but why would it only happen after sitting for a lil while and not right away?

vrg3 · Post by **vrg3** » Sun Mar 14, 2004 5:11 am

Injector cleaner can do a lot more if your injectors are dirty than if they're not very dirty, so if you already have some Sea Foam it can't hurt to dump a little in the tank. But, yeah, I feel like Chevron's fuel treatment with the Techron additive made a small difference each time I've used it on a "mature" car.

One time on a trip I got a bad tank of gas in my 95 Honda Odyssey. It felt like randomly the car would decide to run on 3 cylinders. It only did it a little at first but it started getting worse. I stopped to a gas station and they said they'd siphon all the fuel out of the tank if I filled it up with their fuel. The problem seemed to stop getting worse but was still there. I stopped at Target and got a bottle of Techron cleaner, dumped it in, and the problem was gone within 20 miles.

I have no explanation for why it wouldn't have happened immediately after you last touched the engine bay. But a vacuum leak is easy to search for if it's big enough to cause the engine to stumble.

BAC5.2 · Post by **BAC5.2** » Sun Mar 14, 2004 6:13 am

I've noticed that when I rev, it almost sounds like the car is about to backfire. Lots of pops and burbles.

I just noticed this today and was wondering if it's an attribute of the stock Turbo cars? The only other Turbo Legacy I've ever seen is Boostjunkies, and his isn't exactly stock in the exhaust department.

Ideas?

Kelly · Post by **Kelly** » Sun Mar 14, 2004 6:30 am

you say the tank was really low?

Is water lighter than gasoline? Could there have been gunk floating in your tank?

I second the Techron suggestion, especially if youve never run it.

vrg3 · Post by **vrg3** » Sun Mar 14, 2004 6:32 am

BAC5.2 - I have a stock exhaust on my turbo and I haven't really noticed anything like that.

rallitektech - I think water is heavier than gasoline. That's why fuel tanks can rust through if water gets in them.

evolutionmovement · Post by **evolutionmovement** » Sun Mar 14, 2004 6:58 am

Water is definitely heavier than gasoline.

Thawa - when was the last time you replaced the plug wires? The only time my car ever misfires is when the wires go (which hopefully won't happen anymore now that I got Magnecors).

I used some Sea Foam today and it instantly cleared my recently wavy idle (after I removed and cleaned the PCV valve since I made the mistake of dumping the Sea Foam in the rubber hose that comes out of the valve. All the crap in the hose was instantly shoved into the PCV valve and gummed it up). Didn't think much of it at first but after about 5 miles the car had power like it hasn't had in months and the engine roared instead of sounding like a dying tractor.

Steve

THAWA · Post by **THAWA** » Sun Mar 14, 2004 7:16 am

plug wires about 6 months/5k miles ago. I'll try the techron stuff, and hopefulyl itll help.

THAWA · Post by **THAWA** » Mon Mar 15, 2004 4:26 am

i just realized i also changed out three of the fuel hoses, well two fuel and one return hose. Could this have something to do with it? Maybe i should reset the ecu and see if it happens again?

vrg3 · Post by **vrg3** » Mon Mar 15, 2004 4:39 pm

Oh... then maybe you just need to give it some time. When you replace portions of the fuel supply sometimes it takes a while for them to get fully saturated with fuel. In the meantime you occasionally get insufficient fuel flow sometimes. You probably ended up losing a lot of the fuel charge from the filter while changing the hoses too.

The hoses are all snug and tight, right?

THAWA · Post by **THAWA** » Tue Mar 16, 2004 2:36 am

the fuel hoses are as snug as they're going to get, the hose before the filter(if you're working from the pump to the engine) is about 2 mm's from where the first one was and the other is just fine. The evap hose however is about 1 cm from where the old one was I think I'll just give it time. Today it didn't act up until I got home from a 10ish mile drive.

ciper · Post by **ciper** » Tue Mar 16, 2004 2:43 am

I say grab some old plug wires if you have them and swap them out.

Make sure the wires arent touching each other or anything else and clean them off.

THAWA · Post by **THAWA** » Fri Mar 19, 2004 5:06 am

I switched the wires around like ya said ciper but no help. Also it's been almost a week and its still stumbling and backfiring, is that normal for new fuel lines? I did feel the hose going to the rail after the filter and if felt like it was pulsing, is tht normal? I never took the time to see wht it felt like bfore I change the hoses so I dont know.

THAWA · Post by **THAWA** » Sun Mar 21, 2004 6:12 am

for anyone that cares it is the plug wires. Morgy suggested wrapping them in electric tape, since he did this when he was having the same issues. Soon as I did no more misfire.

so no more autolite wires. Gunna order some magnecors

legacy92ej22t · Post by **legacy92ej22t** » Sun Mar 21, 2004 8:22 am

Right on. I don't like Autolite wires. I put some on a work truck once and they made it run like crap.

A friend of mine knows a mechanic that told him a really easy way to check your wires is to wipe them with a wet rag or spray them lightly with a spray bottle and look for any steam. If they steam then they're bad. Anyone else ever heard of this or tried it?

THAWA · Post by **THAWA** » Sun Mar 21, 2004 8:26 am

morgy had actually suggested the spray bottle aswell, but you cant see spasrks well in theday

NICO · Post by **NICO** » Tue Mar 23, 2004 10:02 am

my car has that problem to. i have to change wires & plugs twice every year, and coil pack every 2 years. the car will stutter if it dont get new ones.

i just orderd a new motor wireing harness for the motor. i think this will help out the most, subaru makes shit thin wires that heat up and cool down and crack no good.

georryan · Post by **georryan** » Tue Mar 23, 2004 11:16 pm

I agree that the wiring harness should help you out a lot. How much did it cost you?? How much do new coil packs cost? I want to find a diamond one.

NICO · Post by **NICO** » Wed Mar 24, 2004 8:33 am

the harness was $250.00 and coil packs are $175.00. i had a diamond and reguler coil pack from subaru, i dont notice nothing.

evolutionmovement · Post by **evolutionmovement** » Wed Mar 24, 2004 8:44 am

I go through cheap wires about once a year, too. Just got some Manecors. I hope they last like they say.

Steve

minoru · Post by **minoru** » Fri May 07, 2004 1:33 am

What about NGK wires???Are they good? For me nothing hapened yet with those. They were on the car when I bought it and I have no idea how old are they. They are all greasy and dusty. I would say they are at least 1 year old.

THAWA · Post by **THAWA** » Mon May 10, 2004 3:16 pm

ngk's are the same as oem I believe.

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Backfire?

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