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#1
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A battle I just can't win
So, I just can't seem to figure out this stumbling issue. If you look in my other thread here you'll see that I replaced my spark plugs and picked up a stumbling and idle hunting issue. I've followed all the suggestions in that thread and even done some of my own and nothing has fixed the problem.
The problem is this: The car stumbles fairly badly when cold. It also can't find idle and stumbles enough to shake the engine. It will also stumble randomly when warm. Seems strong if I am really hard on the gas. Here's what's been done: Tested to see if the stumble follows a coil - no response from the car Replaced fuel filter Replaced front knock sensor (ECU threw a code - sensor was broken) Greased all coil boots with dielectric grease Replaced MAF with known good MAF Cleaned throttle body with TB cleaner Cleaned IACV with TB cleaner (emptied about 1/4 of the can into the IACV, made lots of smoke) Ran Seafoam through gas Sealed minor exhaust leak After all that, still no change. I want this stumbling and idle hunting gone. If anyone has anymore suggestions I am open to them. If they involve spending a lot of money, I will probably be a little more hesitant.
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-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#2
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IACV... I wonder if that can be cleaned like that and still work properly...
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Danny 1994 Silver SVX in hybernation, awaiting for the monsterous awakening (Lebanon) 1967 Mercedes-Benz 250SL Euro Specs, Hard/Softtop, White/Red. Under Complete Restoration 2013 Mercedes-Benz SL350 Euro Specs, White/Red. Mint... Another step into SL Collection. |
#3
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Did you check to see if you have a vacuum leak?
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Seth 94' Barcelona Red w/ Tricoat black 2-tone AWD Ls -Sold Mods:AWD conversion/4.44 swap by Budfreak, Custom red interior lights, Custom Satin black dash, Power mode switch, Cold air intake, Permecool tranny filter,Sony xplode 10" sub, Sony xplode 1000w amp, Blitz in-line driver, DDM Tuning 6000k HID's, New paint job/body work by me, 97' Grill, QC shift kit, 17'' MB Motoring rims, 15&20 min mod, front & rear urethane swaybar bushings, Custom fiberglass sub box, Custom red led a/c control unit, perrin lightweight crank pulley, Black wrinkle finish powdercoated intake manifold w/ clear hoses , 02' outback heated/power black leather seats Soon to come:Fiberglass hood, upholster ALL suede to black leather Past subies: 92' Pearl White/black top LS-L-SOLD 96' Legacy Outback-TOTALED 99' Legacy Outback Limited 30th anniversary edition-TOTALED 98' Forester L -Totaled Other toys: 99' Forester S -WRX brake upgrade, soon an 04 wrx motor swap 06' B9 Tribeca-Stock 1982' Yamaha xj650 Maxim Mods: work in progress |
#4
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I hate to tell you this but you should undo everything you have done prior to the stumbling. As you undo everything look for what could have gone wrong. If it were me I would start with the connections on the battery and all of the vacuum lines after the TB in addition the seal for the intake to the TB. Check for any cracks in the intake especially the plastic fittings where the vacuum lines connect. Then I would check out the condition of the coil wires and finally check the threading and gap of the plugs. Did you use the right plugs? Are they free of any defects?
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#5
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No I did not. However, it doesn't appear that I have one. I can't hear a leak and it goes away slightly as the car gets warmer.
Quote:
__________________
-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#6
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Have you tried disconnecting the injectors to see what happens? The seafoam via the gas tank doesn't stand as much a chance of cleaning the injectors as when you connect a line from the vacuum port on the intake directly to the can of seafoam.
can you explain what you mean by "stumble follows a coil"? If you mean you disconnected each coil (one at a time), then I'm confused that you said "no response from car" (i.e., you should hear/feel a drop off of the cylinder when you disconnect a coil). The fact that the car did not stumble before you changed the spark plugs would lead me to put my focus here first (then again, it could just be a coincidence) -- while the plugs may be right, you might find that you've got a cracked insulator on one or more plugs. -Bill
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Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#7
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might be out of time...
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#8
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Quote:
I visually inspected and sealed each of the coils myself in order to stave off insulation issues. You can see a picture in the other thread of what I did to every coil.
__________________
-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#9
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So one can now assume that it is not a single cylinder causing the problem. You can now either visually check all the vacuum lines or spray them with carb cleaner and listen for a change in your idle. Be careful it's flammable don't spray your exhaust with it! Don't forget to check those connections at the battery as I'm sure those were disturbed during the plug change.
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#10
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A similar instance happened when I was installing plugs into my bf's 94 Laguna. I accidentally bumped one of the plugs and closed the gap on one of them, so that the plug was not firing.
However, the test with the coils should pinpoint a problem like that.
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1991 SVX L JDM |
#11
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I found that on mine a similar issue was caused in part by every bolt on the upper half of the intake plenum being loose. I guess that over time they just got that way, but explained the vac leak I was looking for. Other than that I would think that you have a cracked spark plug ceramic, or a voltage leak in the ignition. Brake cleaner can be a fun way to find a vac leak or a spark leak, but is a little dangerous. You can also use propane bottle with a vac hose attached to pinpoint a vac leak. The idle should raise when you find the leaky spot.
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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin blk 92' LSL w/ average mods pics here http://s306.photobucket.com/albums/nn277/yourconfused/ Cash68: "Hmm, I wouldn't brag about beating Escorts. That's like saying you tricked a retarded person." |
#12
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I am by no means a mechanic when it comes to these cars( I do work on my 69 Vette though), but when you changed the air filter, maybe you moved something that now has a slight hairline crack in it and it is now letting in air/vacum leak? Just a thought.
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Paul 1969 Corvette 1995 SVX L Safety Option Package, HID's & Awsome Braking (Svxfilies/TomsSVX), JDM Clear Corners, JDM Boxer Engine cover, Transmission Cooler, AND NOW JDM FOLDING MIRRORS! 1995 Corolla 2003 Highlander |
#13
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Quote:
If I read your earlier post correctly, the stumble varies with load (?). I'd focus on (1) double checking the plugs to make sure you don't have one that's cracked or has its gap closed up and (2) checking for a vacuum leak (when you "get into it" you're no longer pulling a vaccuum) as you may have bumped a line when you were doing the plugs/changing the air filter. -Bill
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Retired NASA Rocket Scientist Most famous NASA "Child" - OSIRIS-REx delivered samples from asteroid BENNU to Earth in Sept. 2023 Center Network Member #989 '92 Fully caged, 5 speed, waiting for its fully built EG33 '92 "Test Mule", 4:44 Auto, JDM 4:44 Rear Diff with Mech LSD, Tuned headers, Full one-off suspension '92(?) Laguna, 6 spd and other stuff (still at OT's place) My Locker |
#14
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I checked all the lines today with TB cleaner and spraying each line end to end gave no engine response. However, as the car was stumbling for idle, I thought I could hear a slight air leak and it sounded like it was coming from the EGR valve. I spayed the EGR valve with TB cleaner and the engine didn't respond. So I tried to remove the EGR valve and got stuck because I couldn't remove the tube under it.
I do remember back a few months ago I was pulling codes and the EGR code had been thrown at one point in time, but ever since I reset the ECU, the code has never shown up in my car.
__________________
-Jason (8/23/07-Present) 1995 Subaru SVX LSi (197k) Polo Green (#1102) 03/95 Mods: DDM Tuning 4500k 35w Low Beam HID, 100w H3 Bulbs, Extra Ground Cables, 15 minute $12.96 mod, svxfiles designed transmission mount (), sporting a "new" tail light bar, silver BBS rims, custom power steering cooler (one that doesn't dump ATF constantly), new negative lead cable, no more third or fourth gear (1977-Present) 1977 Chevrolet Corvette (81k) Silver (12/01/2011-Present) 2005 Subaru Outback 2.5i Limited 5MT (97k) I have a bad feeling about this. -Obi Wan Kenobi |
#15
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Quote:
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"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin blk 92' LSL w/ average mods pics here http://s306.photobucket.com/albums/nn277/yourconfused/ Cash68: "Hmm, I wouldn't brag about beating Escorts. That's like saying you tricked a retarded person." |
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