1994 sti misfiring problem
17 October 2009, 02:50 AM
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1994 sti misfiring problem
hi everyone im new to the forum as i just bought my first subaru yesterday 
its an 1994 wrx sti. mods are a full exhaust system+decat and panel filter that i know of.
as said im havin a problem with it misfirin for about a second or so when the foot is to the floor then it will clear then go fine. i can give the car say half throttle boost will come in and car will pull fine with no problem its just when its under serious load that i have this problem. can anyone help me plz as im sure you will know.......i know nothin about these cars
since this is my first one. any feedback will be much appreciated 
its an 1994 wrx sti. mods are a full exhaust system+decat and panel filter that i know of.
as said im havin a problem with it misfirin for about a second or so when the foot is to the floor then it will clear then go fine. i can give the car say half throttle boost will come in and car will pull fine with no problem its just when its under serious load that i have this problem. can anyone help me plz as im sure you will know.......i know nothin about these cars
since this is my first one. any feedback will be much appreciated
17 October 2009, 09:04 AM
#2
Hi mate & welcome it sounds like the coilpacks are your problem take them off & pull the rubbers bacK to inspect & there more than likely be cracked there about 60 quid each though & you'll need 4, i'd also clean all boost hoses through with carb cleaner aswell
17 October 2009, 10:11 AM
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^as above really,but if you take the coil packs out,it would be sensible to replace the plugs while you are at it as old worn plugs can cause misfiring too, plugs should be ngk pfr6b's or pfr7b's set to 0.6-0.7mm. thanks bryan
17 October 2009, 06:49 PM
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thanks guys i'll check them out. is the misfiring damagin the engine at all runnin it like this? where is the best place to buy the coilpacks from if they are the problem?
"plugs should be ngk pfr6b's or pfr7b's" what the difference in the types of plugs mentioned? thanks again for your input.
"plugs should be ngk pfr6b's or pfr7b's" what the difference in the types of plugs mentioned? thanks again for your input.
17 October 2009, 07:00 PM
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Sure it's a misfire and not fuel cut due to overboost?
PFR7-B is a colder(think that's right) plug than the 6-B. 6-B's are recommended for standard cars with the cat in still.
PFR7-B is a colder(think that's right) plug than the 6-B. 6-B's are recommended for standard cars with the cat in still.
17 October 2009, 08:11 PM
#6
here's a guide on cleaning the boost solenoid aswell https://www.scoobynet.com/general-te...-what-maf.html as for coilpacks id try David at API Engines on here otherwise importcarparts.com there excellent had loads from them
Last edited by w13dle; 17 October 2009 at 08:14 PM.
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18 October 2009, 11:13 AM
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LOL sounds more like boost cut then.........
Even with a chip anything over 1.1bar will boost cut, its probs caused by the cooler weather we have been having.....
Mine sometimes does it too, mostly on cold damp nights.
I would check the ecu to see if its been chipped, if not lower the boost to std levels.
If it has a chip just lower it a little bit so you dont hit cut at these lower temps, its maybe prudent to do a RR run to check the fueling is ok too.
cheers
Even with a chip anything over 1.1bar will boost cut, its probs caused by the cooler weather we have been having.....
Mine sometimes does it too, mostly on cold damp nights.
I would check the ecu to see if its been chipped, if not lower the boost to std levels.
If it has a chip just lower it a little bit so you dont hit cut at these lower temps, its maybe prudent to do a RR run to check the fueling is ok too.
cheers
19 October 2009, 08:52 AM
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Well folks I don't think the misfirin will make nuch difference now as I manage to smash the car yesterday.
The car is now for sale if anyone is interest? Its the rear end that has took the impact and have pics if anyone is interested. Cheers lee
The car is now for sale if anyone is interest? Its the rear end that has took the impact and have pics if anyone is interested. Cheers lee
