Lloyd Cimprich

I have a 1990 2.3 Mustang that suddenly started a solid misfire with loss of
power. When I asked if there was and unusual bang, crunch, clatter, etc.
just before the loss of power the answer was no. When I went to drive the
car home I am quite sure that for a brief second it ran on all four.

When I pulled the plugs all were fine except #3 which had large (not oily)
deposits on the centre and side electrode.

I replaced plugs with new with no improvement. I quickly removed the plugs
and tested compression, throttle closed and engine cool. This showed # 3 at
30 and rest at 90. Adding a bit of oil to #3 gave 40.

At the suggestion of a local rebuilder I removed rocker cover and checked
cam. Sure enough the lobes were very worn, looked like about 1/16" had been
worn off all lobes. When I reported this to the rebuilder he was quite
confident this (cam wear) was my problem and suggested I install a cam kit
(about $200) or bring head in for rebuild/cam kit.

Any advice/insight would be appreciated, especially as to why the cam would
have been so severely worn.

Thanks

Bob

You need to do a cylinder leakdown test. I don't think your problem is a
worn cam, I'd be more inclined to think you burned a valve.
Bob
"Lloyd Cimprich" <haffacre@echo-on.net> wrote in message
news:67eb4$435af1f8$cf706e22$1162@PRIMUS.CA...
>I have a 1990 2.3 Mustang that suddenly started a solid misfire with loss
>of
> power. When I asked if there was and unusual bang, crunch, clatter, etc.
> just before the loss of power the answer was no. When I went to drive the
> car home I am quite sure that for a brief second it ran on all four.
>
> When I pulled the plugs all were fine except #3 which had large (not oily)
> deposits on the centre and side electrode.
>
> I replaced plugs with new with no improvement. I quickly removed the plugs
> and tested compression, throttle closed and engine cool. This showed # 3
> at
> 30 and rest at 90. Adding a bit of oil to #3 gave 40.
>
> At the suggestion of a local rebuilder I removed rocker cover and checked
> cam. Sure enough the lobes were very worn, looked like about 1/16" had
> been
> worn off all lobes. When I reported this to the rebuilder he was quite
> confident this (cam wear) was my problem and suggested I install a cam kit
> (about $200) or bring head in for rebuild/cam kit.
>
> Any advice/insight would be appreciated, especially as to why the cam
> would
> have been so severely worn.
>
> Thanks
>
>

Lloyd Cimprich

I suspect a valve as well and almost had the head off but had to stop as it
was to cold and rainy to continue. I hope to get it off today.

Due to the severely worn cam I was wondering if there are alternatives to
the stock cam and followers (rollers maybe)?


Thanks.
"Bob" <bob@n0spam.net> wrote in message news:OgD6f.683$xk2.569@fe06.lga...
> You need to do a cylinder leakdown test. I don't think your problem is a
> worn cam, I'd be more inclined to think you burned a valve.
> Bob
> "Lloyd Cimprich" <haffacre@echo-on.net> wrote in message
> news:67eb4$435af1f8$cf706e22$1162@PRIMUS.CA...
> >I have a 1990 2.3 Mustang that suddenly started a solid misfire with loss
> >of
> > power. When I asked if there was and unusual bang, crunch, clatter, etc.
> > just before the loss of power the answer was no. When I went to drive
the
> > car home I am quite sure that for a brief second it ran on all four.
> >
> > When I pulled the plugs all were fine except #3 which had large (not
oily)
> > deposits on the centre and side electrode.
> >
> > I replaced plugs with new with no improvement. I quickly removed the
plugs
> > and tested compression, throttle closed and engine cool. This showed # 3
> > at
> > 30 and rest at 90. Adding a bit of oil to #3 gave 40.
> >
> > At the suggestion of a local rebuilder I removed rocker cover and
checked
> > cam. Sure enough the lobes were very worn, looked like about 1/16" had
> > been
> > worn off all lobes. When I reported this to the rebuilder he was quite
> > confident this (cam wear) was my problem and suggested I install a cam
kit
> > (about $200) or bring head in for rebuild/cam kit.
> >
> > Any advice/insight would be appreciated, especially as to why the cam
> > would
> > have been so severely worn.
> >
> > Thanks
> >
> >
>
>

Lloyd Cimprich

Finally got the head off and found, as suspected, a bad valve on #3. The
exhaust valve actually has a small triagular chunk out of it!

The bottom end looks good but it is dark out so I will check more closely in
the daylight.

Unfortunately I sheared a head bolt leaving about 1/2" sticking out of
block. Any suggestions on the best way to remove it would be appreciated.

Thanks.


"Bob" <bob@n0spam.net> wrote in message news:OgD6f.683$xk2.569@fe06.lga...
> You need to do a cylinder leakdown test. I don't think your problem is a
> worn cam, I'd be more inclined to think you burned a valve.
>

Bob

"Lloyd Cimprich" <haffacre@echo-on.net> wrote in message
news:7cf5a$4362cf67$cf70179f$14782@PRIMUS.CA...
> Finally got the head off and found, as suspected, a bad valve on #3. The
> exhaust valve actually has a small triagular chunk out of it!

Yup, that's what a burnt valve looks like

> The bottom end looks good but it is dark out so I will check more closely
> in
> the daylight.
>
> Unfortunately I sheared a head bolt leaving about 1/2" sticking out of
> block. Any suggestions on the best way to remove it would be appreciated.
>
> Thanks.

Soak it down with penetrating oil and let it sit overnight. then clamp a
vice grip on it and try to break it loose.... wiggle it back and forth and
keep lots of penetrating oil on it. Patience is your friend, don't break
that stud off or your job will get much worse.
Bob
> "Bob" <bob@n0spam.net> wrote in message news:OgD6f.683$xk2.569@fe06.lga...
>> You need to do a cylinder leakdown test. I don't think your problem is a
>> worn cam, I'd be more inclined to think you burned a valve.
>>
>
>