hi guys
i got a problem that has got me completely stuffed..
its my ea with the au engine. it has started missing under load almost like a cyl is not firing and it will surge and backfires and crackles out the exhaust under load at or after 2500rpm and it shakes and idles rough.
but free revs fine.
so far ive changed.
leads=new
spark plugs=new
rotor button=new
dizzy cap=new
distributor=new and 2nd hand
injectors=twice
map sensor= 2nd hand
tps= 2nd hand
fuel filter=new
fuel pump=new
ive given the engine a compression test and all cylinders are strong.200 psi each cyl.

the only thing i havnt changed is the coil which i only thought about while typing this lol.
its now booked in at cms on thursday for a check over but if i can find the problem now i wont need to burn it later lol.
any ideas will help!!

Last edited by TROYMAN on Thu Dec 04, 2008 11:28 am, edited 2 times in total.

Yeh, its the coil.
First things to change/check are the leads,plugs, dizzy and coil. Most of the time it'll be leads or coil.

thanks
i bloody hope so lol.
thats what ill try tomorrow.
yea usually its leads plugs ect.
but this time the coil was out of site out of mind...

Last edited by TROYMAN on Tue Sep 09, 2008 6:08 pm, edited 1 time in total.

?woops double post

+1 for coil mate.

Hay Troy, ive got a few spare coils if you want to try one.

Run the car in the dark with the bonnet open.. when I did that I could see arcing in several places..

since I fixed them all my old girl has picked right up..

the missing under load symptom was exactly what I experienced..

cheers guys

im going to try a new coil today and see what happens.
i tell ya what if it is the coil im going to kick my self for not trying it first lol
to be honest afaik its still the original coil.
and when i did the engine conversion i used the same coil.
fingers crossed guys...........

well its still f**k

i changed the coil and no difference...
its going to cms to see if joe can find the problem..

im thinking it may have a blown head gasket?
but im not to sure as its not showing signs of coolant loss yet..
2 things that make me wonder is it warms up very quick and doesnt start backfiring untill its warm. but still misses all the time...

so at the moment if its got a head problem i might just wreck the thing out.
and buy something else..????

here is a vid link of how crap its running.
http://au.youtube.com/watch?v=4mn4GPyr-bU

Don't do that.. think of all the effort you've put into your beast..

Are any of your plugs a different color from the others?
I know they are new, but if one is steam cleaned and the others aren't, you'll have an answer.

When I had those exact same symptoms it was mostly the lead from coil to dizzy, but you've changed that with the leads I spose. I also had a loose intake manifold which sucked air.

you can't sell up.. you are one of my sources for inspiration on here...

im just p****d off..lol

im about to look at a eb replacement..
to get me around untill i fix it or wreck it..

what made you think it's a head gasket?

I still think it's somehow ignition related...
I've had a couple of blown gaskets, and the symptoms were not as you describe them either time. My thought is that any leak bad enough to cause what you are describing would be showing other symptoms.. water in oil or bubbles, hard starting, crankcase blowback etc etc..

One other symptom I had from the bad leads.. when you tried to start it sometimes, it would spin more or less normally till it got to one cyl in particular and it would f@rt and almost come to a stop, then it would spin up again.. It was cos of that that I briefly thought I had a blown head gasket.. (but plugs where new and all identically marked grey black) and had no other hg symptoms so went back to ignition.

Go to supercheap and look for a spark tester.. I bought one for 3 bucks and it found my problem straight away..

My plugs, leads, dizzy all looked good, but it still ran like cr@p when warm and f@rt and missed etc under load.

The tester has a light on it.. you put it near the lead and the light lights up via inductance.. and you can see the spark at the plug cap (I suppose an inductance timing light would work for this purpose also).. I found that every tenth (roughly) spark was missing on one lead.. and that was at idle. but you didn't notice the miss at idle...

later on I went out at night to use the tester again.. and discovered two more of the leads were arcing internally past internal breakages and the leads themselves where kind of glowing in that area.. so I didn't need the tester to see that, but for trouble shooting, nothing beats actually seeing the spark at the end of the lead...

Once I fixed the arcing, it's perfect....

i know it sounds ignition related but there is nothing left to replace..
all ignition parts are now new...
all the plugs are nice and grey..
there is no sign of coolant loss.
i was thinking the head gasket maybe leaking between 2 cylinders or a crack in the head??

all i know is its doing my head in.....

Bad earth somewhere.... not sure how to check that though?!

Thats a possible option, but wouldn't there be other symptoms with that too?