I am unsure of the history of my EA 3.9 MPFI but in trying to sort out a heap of running issues I went to fit new injectors tonight. When I removed the old ones I checked the injector ports visually and found the No.3 port half blocked off on the upper side. I poked the blockage and it is very hard and if I'm right it is actually cylinder head material? The No.6 port is even worse although being dirty and hard to see I'm not sure.

I looked up online and found a tech bulleting talking about MPFI engines fitted with CFI intake gaskets but that suggests all ports would be partially blocked off due to the non-injector gasket. Which makes me wonder if someone has maybe fitted a CFI head or something in the past? (it has the original engine number though).

Strangely the car has had bad vibes when accelerating above say 2000rpm and this may suggest why.

Anyone advise if this is a head thing and why cylinder 3 and 6 might be this way?

No replies or ideas so I ripped off the intake manifold and have to say good old Geelong casting plant have excelled themselves on this one How this car got to 290,000km with this is beyond me.

After taking the manifold off I found the No.1 and No.6 ports partially blocked by the intake gasket. The gasket had shrunk in the section between ports/runners and in doing so pulled the gasket through ripping the bolt holes. No.6 was so far across it was blocking off the injector. Put this down to old age of 21 years on and off the road plus 290,000km which ain't bad for an original engine and head given what used to go wrong with EA head bolts and all that.

But the cake goes to No.3 where I found the head casting was defective. What I found was that the injector port was mostly non-existent, so the injector has been firing into a preverbial brick wall all these years. I got the round file and half round needle file out and made it right. Will post a pic when I get the camera charged up and work out how.

I am suspecting after this the old girl will gain a few herbies under the bonnet!

yeah be keen to see a pic of before and after
never heard of this before........

Just trying to attach the picture finally. Closest in view is a correctly finished port, second back is the casting showing how teh injector has been fiting into a wall for 290,000km!!!

 

 

Attachments:

File comment: Picture of badly cast injection port. DSC02911_35%.jpg [ 301.12 KiB | Viewed 158 times ]

xf was the same,check the head and intake to the new gasket,you will be

I use hi-temp grease on the intake gasket, helps to keep them softer for longer, and not to shrink too much......need to check the bolts every so often too.

Obviously the gasket is one thing, but casting the head like that and not noticing it during engine build is really poor form.

hmm as if it even ran at all , mine with a slight fuel pressure problem / injector clogged slightly wont even run right at all

your very lucky