Ignition Coil Q

[bgd73]

Can an old coil defy the time to spark by delaying/elongating fire?

My tach gets a burp simultaneous to an engine burp lately. I have an exhaust fire noise out one head that goes away at about 1500-2000 rpm (I am certain it is #4 cyl).If timing belt, it would get both cyl's on one head.I have done all normal tune-up stuff (plugs, wires,rotor, cap). Before I buy, if it is problem, does a higher volt fire coil hurt the ea82? should I go with OEM equivelant coil?

I even steam cleaned engine to get rid of battery alkaline and other uknowns (causes similar aforementioned errors).

[[HTi]Johnson]

I've used Accel Super stock (8140 or something) coils for 4 years now, with no problems. Some people will say that it will fry some stuff. But with 4 years of nothing but good, I'd say it's safe and the "frying" was probably an error on someone's part.

[bgd73]

Great! ty. Another way to step up coil safely is with Bosch Platinum plugs (very small precise tip<--fantastic with aluminum heads). I will add stronger coil to my spring fix-up list....

I did get jumped by rusty coil with my socket wrench (just a few min ago!) . It's time to scrap it.

[tizzle]

From what I've heard, bosch platinums plugs should never go on a subaru

[bgd73]

really? Do you know why....?

My brother put some in his Nissan and killed it (head problems), I have had no trouble at all. They also saved my bro-in-laws stubborn 400ci GM with aluminum heads.I figured cast iron and aluminum together, it would be even better in all aluminum.

I ended up painting the old coil and wrapping it in electrical tape while paint was still tacky(experiment). It made no difference in how the engine runs. Prevented short circuits and crazy tach, temp guage isn't a slow yo yo anymore... 312 chores to go, and I'll be starting over like a typewriter.

[bgd73]

Ok, the platinum plug difference(from 2001 forum post about Subaru and platinum plugs):

 

Electrical Resistivity (ohm-meters):

 

1. Silver: 1.59e-8

2. Copper: 1.673e-8

3. Gold: 2.35e-8

4. Platinum 10.6e-8

 

Simply higher for platinum. A post claimed it triggered a CE light on an impreza, more than one claimed they worked just fine. I am at 22000 miles in less than a year with them, no probs.Maybe young engines and all thier cleanliness are sensitive to the resistance? I have no idea.....

[mikeshoup]

Platinum is just a poorer conductor than copper. If you have a weak coil, it could cause weak sparks.

[tizzle]

really? Do you know why....?

 

Just hav heard it a billiion times

 

http://www.ultimatesubaru.org/forum/showthread.php?t=29218&highlight=bosch

[Cougar]

Since a coil can't tell one cylinder from another I doubt that changing the coil will make a difference with the missing if that is what you mean by a burp. The trouble is more likely to solved by replacing the wires or the plugs. I would recommend you stick with any line of NGKs. There have been no complaints about those plugs but there has been with Bosch using them in the Soobs.

 

Sometimes using the Seafoam trick cures these kind of problems also. Sucking some into the intake to remove the carbon deposits.

[bgd73]

It was no doubt the coil. I was trying to tighten a cam casing bolt up top while engine was running while it was hot... *Zap* by the coil to cyl head via me.I noticed coil was rusted and flaking and unpainted in spots.I painted it to experiment and it now has no shorts, and 7000 rod throwing rpm

I saw aftermarket replacements with coils still just simply painted. I'll go with my hack job covered in electrical tape to the end. This could be the platinum difference (affects the coil built in resistance?)

 

A billion times to hear about platinum spark plugs being bad in Subarus must have at least one fact. I stated mine. Error free....:-\

[Cougar]

If you are getting zapped like that it means there is a "leak" somewhere. You should replace the coil or wire if that is the cause. The coil needs a good ground connection to work correctly.

[bgd73]

I agree. My expirement worked for now. Coil still on "to do" list. Why use a ground wire upon a complete route when it can take a detour ...called a short circuit. Unpainted metal baring suby coils aren't very friendly

[GeneralDisorder]

Basically the ignition system is designed to do one thing - ignite the fuel. If it does that, then it's working. There is really no sliding scale here. Different plugs, different coils etc are largely gimicks to sell you stuff you don't need.

 

I use the cheap NGK's and have no problems. I had a set of those platinum jobbies that came from a used engine I got (owner had just put them in trying to get it running ), didn't make a bit of difference. Besides that - weird slots or grooves, and strange metals on the plug electrode surfaces make it hard to clean and re-gap them later. Give me plain old plugs, a proper gapping tool, and some sandpaper any day.

 

Maybe they last longer or whatever, but they would have to last a REALLY long time to justify the cost. The NGK's are like $1 each :-\

 

I replace the plugs when I get a vehicle, and then NEVER again. They can be cleaned and re-gapped easily, and should be anyway at every few oil changes. I've never had to buy a new set of plugs for a vehicle that I have not just bought. Eventually (takes a LONG, LONG time), the electrodes will wear away to the point that cleaning and gapping is no longer possible, but I have not reached that point with any of mine.

 

The Accel coils used to be good but are now produced in mexico. The failure rate on them is extremely high lately. Junk. Napa sells a unit that is from the same plant that Accel used to use for theirs... do a search there is a whole thread about this.

 

The coil resistance is matched to the ignitor resistance - using a different coil for "more powerful spark" which is of dubious use at best anyway, is just asking to burn out your ignitor. The stock coil's work great, last nearly forever, and are cheap at the junk yard - what more can you ask for?

 

Get a universal V8 8mm plug wire set and make yourself two sets of plug wires from it. The stock wires are 7mm and I've had arcing problems with older wires. I just use the 8mm universal sets cause they are cheap, and the 8mm wires stand up a little better to time and fluids.

 

GD

[bgd73]

I learned accels on a v8 , they are bad for the most part! I was shocked (pun intended) to know the suby coil had to stay painted- the *only* layer keeping it from taking a detour(for 13 years!).The platinum plugs I got for under 2 bucks a piece, I can't complain. I saw that precise node on them and thought "finally- why in hell don't all plugs stay this precise" . The version I got doesn't have a nub "glued" to it, it is the whole end staying strong (thier were bad ones a few years ago, by Bosch- I guess the ends on some even fell off into the chamber!).Regular spark plug ends have a regular wander - just change fuel and outside temperature and the one of many many other factors that try and "blow out the fire".Sometimes spark wander is good if your engine's design can go to piston-plug detonation,You wouldn't ever want the same spark twice .(soobs don't and won't ever- the aluminum heads are way to attractive to find an end to the spark.) Mass production has cheap contracts for thier mass volume. I will not only doubt many OEM parts, I will experiment to satisfy the "little" truths untold/unspoken.I believe plugs is only one of quite a few things found on my old soob:confused:

[GeneralDisorder]

One thing of note - Subaru just lays out the models of each brand of plugs that will work. Classically, the subaru being an import they were shipped to the dealer with no plugs (being on a boat from Japan, they didn't want the cylinders to rust). It was up to the dealer do decide which brand of plugs to use. My 86 sedan for example came off the lot brand new with a set of Champion plugs :-\

 

GD

[bgd73]

I wonder if they shipped them out loose....Mine did have the original NGK in 3 cylinders.

Anyway, I am still misfiring. I am at a loss.

if coil is just good or bad , and I've made old one better, I must have yet another problem.It seems like engine knocks a bit when it does it. Great idle, and really comes to life at 2800 rpm,slowly but surely, inbetween is still very important to me and local driving. I have no idea how to fix it.Spits and sputters and outright misfires, any type of plug.

[GeneralDisorder]

Perhaps a vacuum leak - spray some carb cleaner around the manifold and see if the idle increases or smoothes out. Easy test to rule it out.

 

GD

[bgd73]

Yes test was good. That was my no#1 problem a year ago. there were things so loose I don't know how car ran! I just recently tightened up oil pan bolts by much more than 1 full turn a piece. The cam case by half turns, the intake was leaking fluid, the spfi was also loose in certain spots.

The problem seems so much electrical related , ECM perhaps. There's as if to be a flim flam around max torque rpm. Sometimes it runs like a tractor trailer (very strong at lower rpms) other times it's like a dragster with fat cams rockin the engine in anticipation waiting for 10000 rpm at the green light to go.

My old DL did this just once for a few weeks. It suddenly stopped and I went another 6 years flawlessly... I don't see that happening on this SPFI. Maybe I go to junk and get old distributor and carb

[GeneralDisorder]

I'm no expert on the SPFI (just learning about it myself), but it sounds like a sensor issue perhaps. I know the O2 sensors get old and slow, and I've had one fail completely on a feedback carb once - original sensor - 150k on it at the time. Maybe check or try another MAF, and the coolant temp sensor is also a good one to check out... the TPS is sometimes an issue, but I would think your problems would be more pronounced. Just a guess.

 

Remember - it may *seem* like timing, but the fuel computer controls that....

 

GD

[Cougar]

If you are getting shocked by touching the case of the coil this means the case ground is not good. The case of the coil needs to be grounded properly to provide the ground to the plugs. If you make sure the ground is ok it will probably fix your problem. The high voltage of the coil will try to find a path to ground want ever way it can.

[MachineAgeVictim]

I'm currently having the same problem with my wagon

 

I've done all the same test and replacements too, I'm about to change my distributor from points to ele.

 

what part of the coil do ground better? the part that has the resister?

 

anyway I was just wondering if anyone has done an upgrading grounding mod on any of these old cars? I thought that it would atleast help the ignition flow smoothly

[bgd73]

There is one ground larger near alternator side of engine. That checks out good, things should be good. A sensor may just be problem... I forgot to mention on my old DL with similar problems, I had put in an ice cold thermostat.I *had to* put cardboard over the radiatior in winter to get heat for the sake of engine running very well. The intake was getting taken over no matter the decent electrical due to heat (never an overheat- just regular running temps showing good).As if to constrict what it needed. The SPFI is even more sensitive. After initial warmup, it is powerful and smooth. When thermostat is open, it does start going into the problems. Not using fluid (<1 gal in 13 months),I can rule out burn/leaks. I will drop thermostat to 160-ish. Even that changes electrical!

[Cougar]

To MAV:

 

Make sure that the coil bracket and body of the coil are clean and have good electrical contact to make a good ground to the engine.

 

To bgd73:

The heat problem sounds like it is due to a clogged heater core or the heater temperature control is not working correctly. Since the engine temp seems ok along with the coolant level those things should be good. Going to a lower temperature thermostat won't help this problem. If the engine temp reading was low I would say the thermostat is stuck open but since it appears normal that should be ok.

[MachineAgeVictim]

my problem is worst when the engine is cold, does that make sense? (sorry to highjack)

[bgd73]

mav:

Mine was same at cold. I did a bunch of stuff and it flim-flammed into bad at warm. Someday it will be narrowed down to the truth of it all....

I can only work with ECM and its abilities. the switch happened on mine when I finally gave engine air and less restrictive exhaust. Perfect when cool/cold. Keeping it cool all the time will fix mine, knowing electrical is good, it is the only thing left.When engine is cold it gets more fuel. more fuel needs more air.Once you have ruled out coil, etc. target these things.Is your idle good when cold? there is a screw you can tinker with on spfi unit to help it some.