Sputtering and jerky idle (relisted) pls read
 

Hi, i thought to start that topic again as that post went too far with no result and not great amount of information. I believe many ppl have the problem.

So why dont we, who have the problem, describe it and write the actions u have done and what have changed or if u fixed problem, share the secret.

OK i start:

It started to happen after i changed the spark plugs
Symptoms: when its cold, its sweet as, then after 2-3 minutes of driving or 3-7 mins of idle it startes to miss with some kinda clicking. Like it can work fine for few seconds then it misses, engine shakes, then fine again. Also after driving, and stayin on the lights, it can just idle bad as with RPMs dropping to 400 and then back to 1000 and going like that and shaking the car. Plus my acceleration sometimes was in wave pattern: same throttle opening but car accelerates faster/slower.

I ve checked the sensors for bad contacts - did not help.
Changed the vacuum hoses (which were just terrible and its good ive changed them) but still no luck. Then i ve read that bad PCV could be the problem, and changed PCV with a hose going from it. Still no luck. Oh yes, i definitly tried injector cleaners... and no luck at all.
Then i thought it can be fuel pump or pressure regulator, but i have experienced problem for 5 months and fuel pump dies in few days. Then pressure regulator... i disconnected that vacuum line to it, which turned regulator off, letting the maximum pressure.. but problem was there... so that excluded the pressure regulator and pump... also O2 sensor and MAF sensor could be the suspects, but someone changed them with no luck so i could not be bothered... also i did disconnect the MAF and drove without it and car acted the same...

and today... i did the thing i ve done the first when i started to chase the problem... but beeing patient....

unpluging the injectors 1 by 1, and 1 at the time and waiting for a minute or so... which gave me that only 1 injector (cyllinder) give me stable 5 cyllinder opertaion and rest 5 give me unstable (rough) 5 cyllinder idle...

so now i ve narrowed my search to:
1) injector
2) injector controlling electronic system
3) Spark plug
4) Coil

then again, spark plug was new and it was proper NGK platinum one, so i doubt it can be bad.

The injector has "1" written on it, its second on the left if u look on the engine from upfront (passenger side in USA)

there are 2 injectors with "1", 2 with "2", 1 with "3", 1 with "4"


ok and now i need ur help guys... again :( :

is my logic correct and im left with 1) 2) and 4) and how can i narrow my search here and repair it? pls take into consideration that i would preffer to spend as less money as i can...

i.e anyone got description/pictures how injectors work and controlled? and if i can check the coil (i think its my last guess out those 3 as car works fine when its cold...)


p.s. hope this can help to the rest of u strugling...
but still pls write ur symptoms and what u have done.. it actually can help the rest.(at least dont spend time and money changing everything :p)

92 ls-l w/ 135k
Symptoms
Only on cold start
Car starts and idles fine
After driven for approx 1 mile and then idled car runs rough
Feels like it's missing on a cylinder
After a minute or so of rough idle/ rough driving problem disappears and does not come back
This problem appeared randomly - no work had been done on the car when it started pulling this.

tried:
-shutting off car and restart when symptoms come up - didn't work
-swapped MAF with known good MAF - did not help
-injector cleaners - no help
-car got new plugs at dealer at 100k (I hope they were platinum - P.O. had done)

-If car is left to idle in driveway up to operating temp before driving it the problem does not come up.

Re: Sputtering and jerky idle (relisted) pls read
 

I can swap ECU's to knock out #2 above.
The others will take a little work and it's colder than hell out. If it warms up today I'll see if I can narrow it down to 1 cylinder.


Since you know which cylinder you have bad you can switch injectors between 2 and see if the problem moves.

1) are u sure they are exactly the same?

2) how can i swap em? (is it as simple as unscrewing those couple of bolts?)

3)does having 2 injectors with "1" on them, mean that they are the same and i can replug them (swap wires and connectors going to them)

(to see if it controlling system..)

hey dont bother swapping ecus

if i can swap injectors and then connectors i ll narrow the search definitly to something particular...

cheers :)

hope this method can help u too... but ur problem seems to be more weird then mine!!

The fuel injectors are interchangeable.
I dont think you can swap the wires though - they'd be out of phase - that would be bad.

Relieve the fuel pressure by unplugging the fuel pump under the rear seat and running it out or by clamping off the fuel line

Take off the cap over the fuel injector (2 phillips screws) and unplug it
First try pulling the injector out while turning it to the 90 degree mark. You might be lucky and it will slide out easily.
If not - twist the fuel injector 90 degrees so the angled part is over the fuel rail
use a large flat bladed screwdriver to pry up on the red plastic part of the injector to remove the injector.
Be very careful not to break anything. The injector should come up pretty easily - try not to gouge the red plastic.

There is a how to on this somewhere, Im trying to find it now.

ok ill try that


also will try to c what i got in my online manuals.. :)

Speaking of ignition electronics, can anyone confirm if this piece has ever been a problem on anyone's SVX:

http://dcss.dyn.dhs.org/pics/whatsitdo.jpg

Ignitor!
 

no.

w.t.f is it man?

Sputtering and jerky idle
 

6EVIL9
I have the same problem. It usually occurs when I really stomp on it before the engine warms up (like pulling out in traffic), and then at the next stop it really runs rough. If I let the engine warm up, it doesn't happen. If I don't let it warm up, but drive gently until it does, it doesn't happen. Sooo, I've concluded that one of the ignition coil packs (there's one on each plug) is breaking down when the engine is cold. When I stomp on the accelerator a bunch of fuel is dumped in that cylinder, and with no spark, the engine runs verrrry rough. At least thats my theory. I've learned to adjust my driving habits until I get around to exploring it more...
cayent
92 SVX
01 VDC

What timing! I was looking for a solution to a similar problem and found this site. Unfortunately, I have no solution but more data...

My wife's 1994 SVX LE, 49k miles
Almost same symptoms as immortal_suby, namely:

Only on cold start
Car starts and idles fine
After driven for approx 1 mile and then idled car runs rough [in my case, also stalls]
Feels like it's missing on a cylinder
After a minute or so of rough idle/ rough driving problem disappears and does not come back

Differences:
I drove the car today, and noted the following. If you slow down or stop wile running roughly, car stalls, and dash lights come on. Can restart right away. Also, when running roughly, I gave it a little more gas to try to keep it running, and the POWER light came on. Strange. I had never seen it. I couldn't make it come on again even by flooring the accelerator.

Tried:
Dealer reported no error codes found, but replaced L/R O2 sensors ($400). Wife reports problem is worse, if anything. Dealer called Subaru, which suggests new plugs, fuel-injector cleaning, and "upper engine cleaning(?)" but no guarantee it will help.

Research on this and other sites suggests that replacing PCV valve may help? Looking for suggestions...

musichem
94 SVX
00 Outback

pretty much the exact same here

i was told that it was vapor lock??

what do you guys think?

I was told once by a respectable mechanic that he never saw an electronic ignition module to provide an intermittment failure. They either work perfectly or they die completely, never in between.

In the interest of keeping this disscussion going, I have researched the two threads and summarized everything that I can find that has been tried. What 's left? Any new ideas? I'll update if ours gets any better...

Things tried that did not work or made it worse:
Changed spark plugs (6evil9)
Replace L/R O2 sensors (musichem)
Fuel filter (mine was replaced recently, James Scott, pylon500)
cleaning the throttle body and AIC (what's this?) (James Scott)
Temperature sensor (James Scott)
Voltage/Continuity Checks (James Scott)
replaced coil pack wire and injector on one cylinder (James Scott)
Cleaned TPS (James Scott, 6evil9)
MAF/O2/Sparks (92Blacknessvx)
Cleaned throttle body and injector cleaner (6evil9)
TECHRON Fuel System Cleaner (James Scott)
PCV Valve changed (6evil9)
MAF (immortal_suby)
check ECU under dash (6evil9)


Suggestions:
Bad fuel (Immortal_suby)
Went away by itself (Motorsort-SVX)
Add "dry-gas" , MAF(MoodyBlue)
Check/replace all vacuum hoses (6evil9)
turn screw to open idle opening of throttle butterflies (6evil9)
Restore 6 cyl. engine oil treatment, then Fuel System cleaner (nextcubepro)
injector/electronics (6evil9)
sparks/coil (6evil9)
allow to warm up at idle (immortal_suby)
bad ignition coil pack (Cayent)

sorry for beeing out for a while...

ok what i think is that even if u have similar symptoms we mite have different problems

Matt have u tried to see if its ur cyllinder misfiring or whole petrol system is bad? (same as i did)

which i advise to everyone. as: if u find out that it s ur cyllinder misfiring then changing MAF, O2, TPS, temp sensor and all that is just waste of money

otherwise if its the whole system and not one of cyllinders, then changing coil packs and sparks, fuel injectors is waste of time and money.

so save both and spend 10 minutes for that.

vapour lock... do u mean bad PCV system operation? well as much as i read it can cause the car to idle rough, also it leads to LEAKING oil from every seal, and wearing the engine off faster and eventuly car dies.. well its what i read bout that in some educational material...
but not sure if u r talking about PCV system.... but if ur dipstic pops up and o-ring is good, then check the hoses replace them and maybe replace PCV... cheap, but pain in ur hands... :o

so u worry bout that? lol i would worry if it goes away after a minute, not a huge hassle... but wasting $400 on the sensor..
hmm dont forget that check engine should ve tell u bout that, and if it did not then o2 sensor is not a problem... seems like ur dealer just wanted ur money... anyways check for possible codes that "check engine" gives u... and illuminate them :)

seems like its not my case. i tried to leave the car to idle till it gets warm and it was starting to jerk. So maybe u r right about ur coil... but again do what i said before and find what cyllinder it is...

anyways if u want more help pm me..

c u for now