Page 1 of 1

misfiring EA81

Posted: Tue Oct 16, 2007 1:52 am
by roach
hi everyone, i picked up an 85 subaru wagon with the EA81 carby motor for free the other day and its got a misfire. i can see the spark leaking out of the coil lead, so im going for a whole set of leads and plugs. but i also have sparks jumping from the low tension terminals to the high tension terminal coil. i replaced the boot over the coil lead and it made no difference. i have never seen this happen on any coil before and cant figure out why. any ideas?
I did a dry compression test today and got 145psi to 150psi with the motor cold, can anyone tell me what the normal pressure should be?

and one last thing, can anyone tell me where the redline is for one of these motors (1985 EA81 with carby and electronic ignition)

thanx for any help

Posted: Tue Oct 16, 2007 5:47 am
by littlewhiteute
Your coil has a crack in the coil tower or some form of residue which alllows the hign tension spark to track down the tower to ground. Or maybe your leads are really bad, but by then the engine probably wouldn't start.

Compression pressure should be 160, what you have is fine for a cold engine.

I'd also like to know the answer for redline.

Posted: Tue Oct 16, 2007 9:13 pm
by roach
i put the new lead set on today with a little bit of electroguard grease on the terminals and everything was ok, no more sparks jumping from any terminals. so all thats left now is the redline question.

thanks for youre help littlewhiteute. now i know i got a half decent motor, i can justify spending money on the car :)

Posted: Tue Oct 16, 2007 9:39 pm
by Matatak
redline possibly 5500 rpm...rev limiter i cant say i never tryed that high lol.

but i onyl think5500 coz my dash beeps at me when it goes above 5500 rpm and orange lines light up on it lol

Posted: Tue Oct 16, 2007 11:10 pm
by steptoe
electroguard grease eh ??

I'd consider a new coil soon though, just in case the grease ain't a permanent fix. The old leads may have caused chain of events of coil tower sparking.

Posted: Tue Oct 16, 2007 11:17 pm
by roach
thanks matatak, i had a tacho and shift light sitting around so i put it in the subaru. thats why i needed to know the redline :)

steptoe: yeah its a grease i use on the boots of leads, it stopps water getting in and stops the boots sticking to the ceramic insulators on spark plugs. i have never had any sparks tracking through the grease so i guess ok to use.
there was a little bit of dirt around the tower of the coil, so i cleaned the top and couldnt see any cracks and the engine seems to be ok at high revs while under load. but i will keep it in the back of my mind if i have any more probs with it

Posted: Wed Oct 17, 2007 8:36 pm
by Reg Brumbys
I thought I had seen somethingin the Subaru manual that I found on the forum but it was just the following

Ea-81 Stock Engine
Max Output - 85hp @ 4800 rpm
Max Torque - 13kg - m @2400 rpm

Posted: Wed Oct 17, 2007 10:12 pm
by Gannon
Rev limiter on an ea81.... non existant!

They will rev until valvebounce.

Posted: Wed Oct 17, 2007 11:03 pm
by roach
suparoo "Rev limiter on an ea81.... non existant!
They will rev until valvebounce." hahaha

thanks for the help and info guys, everything is sorted out and she runs fine now :) do these motors have adjustable rocker arms or hydraulic lash adjusters? what are the clearances if the rockers are adjustable? cause im thinking about checking valve clearances too

Posted: Wed Oct 17, 2007 11:16 pm
by Matatak
roach wrote:suparoo "Rev limiter on an ea81.... non existant!
They will rev until valvebounce." hahaha

thanks for the help and info guys, everything is sorted out and she runs fine now :) do these motors have adjustable rocker arms or hydraulic lash adjusters? what are the clearances if the rockers are adjustable? cause im thinking about checking valve clearances too
im on about nothing dun worry

Posted: Wed Oct 17, 2007 11:32 pm
by 90brumby
wat r u on bout mat

the ea81 has adjuster rocker arms for hydraluic or solid

Posted: Wed Oct 17, 2007 11:37 pm
by Matatak
90brumby wrote:wat r u on bout mat

the ea81 has adjuster rocker arms for hydraluic or solid


why does Hydraulics need adjustment...

Posted: Thu Oct 18, 2007 12:25 am
by 90brumby
it doesnt but for some reason there still there on the ea81