CIS and low compression...

Hi all. Any old time CIS nuts still hanging around here? It's been a long
time since I gave up my bad rabbit habit... guess I was overdue for a slip
: )
Question: Should a 1.8 CIS run (at least poorly) with 55 to 60 psi
compression?
STOP HERE if you like, or read on if your curious for more details and got
time for a long read! OK, it's not THAT long... but really I just need
imput on if it should still at least be able to fire up and run with
compression this low. THANKS!

I've got this 86 Wolfsburg Cabriol(toil)et with 1.8 CIS... basically a 500
buck car (mistake?) with no spark... but after chasing electical gremlins
finally got spark but then it still won't fire up... not even a cough! OK,
I think starter is tired from the last owner cranking the snots out of it...
so it doesn't spin REAL fast but with jumper cables attached it does at
least spin "fair", but only for a short while. But with an injector pulled
and laying on the valve cover, fuel pump running via jumper, and cranking
starter I can't seem to get enough air flow to lift the fuel distributor.
However, removing boot and grabbing the air flag and lifting it (quite
lightly... smooth and easy) gives good fuel. A good dose of starting fluid
sprayed into the boot also gets no combustion. Not even a cough or sputter.
HA! I thought a no spark condition would be an easy fix but that apparently
wasn't the only problem. Compression test shows only 55 on cylinder 1, and
60 on the other 3. Adding some oil didn't help. I believe the compression
gauge is accurate. It's an oldie but goodie... I'll try it on another
vehicle tomorrow to be sure. Even if compression is really that low,
shouldn't this engine still pump enough air to make CIS work? And shouldn't
it still be able to fire up and at least run like crap?

It just occured to me while typing this... I guess I gotta get under it and
maybe unhook the exhaust (or pull the 02 sensor) to check the possibility of
excessive back pressure. But I don't think that would make low compression,
but it sure might make the starter drag down. Anyway, the boot at throttle
body, duct, and boot on fuel distributor all look fine (will remove and
check them all again tomorrow). I'm puzzled that I can't make this thing
fire up some! Or at least deliver some serious fuel. If compression gauge
proves accurate, I'll probably pull the valve cover and at least check for
some valve clearance. There's no coolant in the oil or in the cylinders.
Timing belt is old but OK, cam timing is dead on where it belongs, and rotor
in the distributor pointing at the no 1 position, the distributor is tight
and the lock down bolt looks like it hasn't been touched in 25 years. The
no spark problem was just a bad ground wire from ignition control module.
This car "supposedly" ran pretty good before that, but I'm wondering if the
spark problem was induced from someone farting around with it trying to over
come this other problem?
I wanted to put this on the road cheap for someone... it ain't lookin so
likely now... definitely don't want to put a new starter in if the engine is
junk. Maybe I'll try towing it up the road and spin her up in gear! The
frequency valve ain't buzzing, so I know I got other electrical issues to
chase down. And the plug is missing above the 3mm rich/lean adjusting screw
so I'm sure that's been messed with... and now I'm wondering if that can be
the problem. Maybe I'll set that as rich as I can (without it dumping fuel
@ no air flow!) and go from there with a "tow start" ; ). Making it run
"right" is a horse of a different color! And may not even be possible given
how hard parts are to come by these days. (can you even get a cpr now?) But
I used to do damn good with these old systems. I've revived a number of
them in the past, but this is the first time I've ever had to resort to a
compression test on one, ever. Maybe I'll see if I can get the frequency
valve working. And of course, don't know what the cold start valve (5th
injector) is doing either. But I'd prefer to chase that stuff down to make
it "run better" and "start easier" after I at least get it to run. So my
question again (if you made it this far)... should it be able to run with
55-60 psi compression?? If so, I'll keep plugging at it. Body's good,
top's good, interior's good, haven't checked front end parts yet,... would
really like to hear it run and see what the clutch and 5 speed does! It
might be a lost cause (and I don't got a 2.0 for it, nor the time to do such
a transplant) : ). Thanks all!

On Mon, 26 Oct 2009 00:28:12 -0500, "In2hoppn"
> wrote:

>
>Hi all.

New plugs. Try starting. Check plugs for fuel contamination/smell.
That will tell you if you are getting fuel into the engine. If they
are clean, no fuel smell at all, then fuel problems still exist. If
they have some fuel dampness or smell, check spark.

Also try a non-contact timing light (inductive clamp on the plug wire
for a spark test if you have one.)

Thanks Pete!
Plugs are like new. Not getting fuel. Using Snap-on timing light.
I take it you agree it "should" run at 55 - 60 psi compression?
I don't know how "good" spark is, but the timing light does continue to show
I have spark.
I'm just ready to go have at it again (for a little while).
I'll update at some point!


"PeterD" > wrote in message
...
> On Mon, 26 Oct 2009 00:28:12 -0500, "In2hoppn"
> > wrote:
>
> >
> >Hi all.
>
> New plugs. Try starting. Check plugs for fuel contamination/smell.
> That will tell you if you are getting fuel into the engine. If they
> are clean, no fuel smell at all, then fuel problems still exist. If
> they have some fuel dampness or smell, check spark.
>
> Also try a non-contact timing light (inductive clamp on the plug wire
> for a spark test if you have one.)

If you realy measured "only" 55psi then it must be leaking through the
valves. Normal value is between 140...180psi! Acc to vw it is due for
overhaul when it is dropped to about 105psi! You'll never get it started
with almost no compression....

First check what the cause is for that low cyl. pressure! If the oil trick
didn't make a difference then it must be bad valves or a very bad head
gasket (unlikely)

SFC

On Mon, 26 Oct 2009 10:59:37 -0500, "In2hoppn"
> wrote:

>Thanks Pete!
>Plugs are like new. Not getting fuel. Using Snap-on timing light.
>I take it you agree it "should" run at 55 - 60 psi compression?

I'm not sure it will. With 80 it would, but not well, never tried
something that low. Keep in mind that it would 'fire' with low
compression but might not start/run.

>I don't know how "good" spark is, but the timing light does continue to show
>I have spark.
>I'm just ready to go have at it again (for a little while).
>I'll update at some point!

Do so, and update us.

>
>
>"PeterD" > wrote in message
.. .
>> On Mon, 26 Oct 2009 00:28:12 -0500, "In2hoppn"
>> > wrote:
>>
>> >
>> >Hi all.
>>
>> New plugs. Try starting. Check plugs for fuel contamination/smell.
>> That will tell you if you are getting fuel into the engine. If they
>> are clean, no fuel smell at all, then fuel problems still exist. If
>> they have some fuel dampness or smell, check spark.
>>
>> Also try a non-contact timing light (inductive clamp on the plug wire
>> for a spark test if you have one.)
>

I think hydrolic lifters play a role...
I did finally get it running. Had to pull it up the street. Runs good,
too. But still won't start by starter. It's just not cranking fast enough.
The starter is just plain cooked and drawing way too much current. It's
cranking like about 1/2 speed... although my 83 will start at that speed if
battery is half dead (like after sitting all winter). So apparently it's a
combination of slow starter and hard starting from the typical fuel ratio
not ideal yet cis syndrome : ) I'm betting compression has come up after
running it and building some oil pressure, but never did check it again.
It had a coolant leak as well, so for all I know it's been cooked a bit...
maybe valve springs are weak now? I don't know, but it didn't want to idle
and I didn't dare let it run too long with the coolant leaking (hose off end
of head) so I didn't do anymore tinkering. But I did drive it around the
yard and out back and it runs smooth and strong... and I at least know now
that the clutch is good, as well as 1st, 2nd, and reverse gears... yard too
small for 3rd, 4th, and 5th : )


"SFC" > wrote in message
...
>
> If you realy measured "only" 55psi then it must be leaking through the
> valves. Normal value is between 140...180psi! Acc to vw it is due for
> overhaul when it is dropped to about 105psi! You'll never get it started
> with almost no compression....
>
> First check what the cause is for that low cyl. pressure! If the oil trick
> didn't make a difference then it must be bad valves or a very bad head
> gasket (unlikely)
>
> SFC
>
>

I was going to say that you need to start with the basics.
Make sure the timing belt is correct. I have seen sooo many that were many
notches off including my 1.8t engine when I bought it. Oh and it had good
compression (150 psi) even for a low compression engine that was 4 notches
off.
Yes the engine could run but might not run at full power or might be hard to
start.
Your compression, especially with Hyd Lifters, might be low until the
lifters pump up and the engine is warm.

THEN check the spark timing.

CIS usually needs that cold start valve to spray a little fuel inside the
intake manifold to make starting easier.

Glad you got it started! ;-)
Check out the main battery cable going to the starter and the main negative
cable to the engine.
I suggest taking them off and cleaning all surfaces.

JMHO
--
later,
(One out of many daves)


"In2hoppn" > wrote in message
news:B4qdnb27NM8WvXvXnZ2dnUVZ_tWdnZ2d@metrocastcab levision.com...
>I think hydrolic lifters play a role...
> I did finally get it running. Had to pull it up the street. Runs good,
> too. But still won't start by starter. It's just not cranking fast
> enough.
> The starter is just plain cooked and drawing way too much current. It's
> cranking like about 1/2 speed... although my 83 will start at that speed
> if
> battery is half dead (like after sitting all winter). So apparently it's
> a
> combination of slow starter and hard starting from the typical fuel ratio
> not ideal yet cis syndrome : ) I'm betting compression has come up after
> running it and building some oil pressure, but never did check it again.
> It had a coolant leak as well, so for all I know it's been cooked a bit...
> maybe valve springs are weak now? I don't know, but it didn't want to
> idle
> and I didn't dare let it run too long with the coolant leaking (hose off
> end
> of head) so I didn't do anymore tinkering. But I did drive it around the
> yard and out back and it runs smooth and strong... and I at least know now
> that the clutch is good, as well as 1st, 2nd, and reverse gears... yard
> too
> small for 3rd, 4th, and 5th : )
>
>
> "SFC" > wrote in message
> ...
>>
>> If you realy measured "only" 55psi then it must be leaking through the
>> valves. Normal value is between 140...180psi! Acc to vw it is due for
>> overhaul when it is dropped to about 105psi! You'll never get it started
>> with almost no compression....
>>
>> First check what the cause is for that low cyl. pressure! If the oil
>> trick
>> didn't make a difference then it must be bad valves or a very bad head
>> gasket (unlikely)
>>
>> SFC
>>
>>
>
>

> Your compression, especially with Hyd Lifters, might be low until the
> lifters pump up and the engine is warm.

Hmm, could you explain this one. When the lifters are drained from oil they
will not hold the valves open. Maybe after a head job when the springs were
removed....

SFC

Have you ever heard an engine with hydraulic lifters start after sitting for
a couple of months?
Sometimes there is a rattle/tapping as the clearance inside of the lifter
needs to be adjusted with oil or pumped up.
So it might be possible that the lifters have collasped not allowing the
valves to fully open and opening late & closing early.
Just a theory and I can not recall ever seeing this before.

NOW I have seen the reverse, where the lifters pump up too much holding the
valves open and engine loses compression. That was caused by an oil pump
that developed way too much oil pressure.

Wild thoughts I know but possible! ;-)
later,
One out of many daves

"SFC" > wrote in message
...
>
>> Your compression, especially with Hyd Lifters, might be low until the
>> lifters pump up and the engine is warm.
>
> Hmm, could you explain this one. When the lifters are drained from oil
> they will not hold the valves open. Maybe after a head job when the
> springs were removed....
>
> SFC
>

Yeah, and "the basics" with an old Rabbit far beyond about any other car...
: )

As soon as I new I had spark and could get fuel out an injector by lifting
the air plate, I had pulled the timing cover and turned her over to TDC and
timing was perfect. Of course, ignition timing at the distrib may still be
off a tad but does need to be running to tune that in. And the clamping
bolt still has a TON of ancient crud on it, so no-ones monkeed foolishly
with it as a wrench had definitly not been on it.

Anyway, before finally towing it up the road with truck and chain... I did
try checking valve clearance. At first, I didn't seem to have any at all
(checking the several that were obviously on the low parts of the cam
lobes). Then, after dismantling my stubby little feeler gauges so I could
get in there better... it seemed I could fit about anything anywhere... on
up to say 0.76 everywhere. THEN I realized I was actually moving the tops
of the lifters downward, which I then found I could do quite easily with my
finger. And here I was thinking this thing had solid lifters! So that's
when I got thinking about maybe lack of oil pressure and the slow starter /
limited cranking time... I had to throw it back together with the old
gasket (that was already leaking) so the cover's coming back off anyway.
I'll try checking the compression again at that time... after it can start
and run... but still cold engine, just out of curiosity... and post the
results.

I have yet to discover what the cold start valve is doing! All I did with
that so far was look at it through the throttle body with my bore scope when
I was doing an injector flow test. Injectors spray nicely (hope dealer
still has some seals but I doubt it). Nicely balanced too. Within specs...
about "Yay" much in each of the 4 Aquafina water bottles... : ) I still
don't know why I could get it to at least fire once with starting fluid,
though. I always thought that stuff would burn with zero compression.

The frequency valve is not buzzing, the throttle cable was totally adjusted
wrong and obviously being used to jack the idle up. So I need to chase down
the electrical side there and suspect if Lambda is dead, so it cold start,
hot start pulse, warm start fade 5 yards and punt,... : )
I'm sure none of the multiple relay diagrams in Bentley quite match up... I
really think VW used to use relays as toy blocks for the kids in the waiting
area and what ever configuration they happen to leave them in was the order
for that days assembly!

But first, I'll need to replace the starter. And since I slipped leaning
over it and broke my nipple... the one that the little expansion tank hose
goes onto... I'll be needing a new radiator, too. Doesn't that just SUCK!
And while I'm in the suck department... one sloppy rod end in the front end
is the extent of trouble there. Clutch works great but the pedal is slid
over half off the pivot point and rubbing against the steering column. You
guys know, down there at the bottom of the steering column where the bottom
bearing has fallen out and is sitting on the little u-joint. All this (and
the last paragraph) just part of "the basics" for an A1. But the wheel
bearings sounded good via "chain drive" up the road : ). Brakes all sound
and feel good. No 4 ways, heater blows one speed only, switch in the OFF
position!, no wipers,... didn't try the aftermarket cd player yet... there's
an undersized wire from under that going out to the battery that I won't be
reconnecting out there... did I mention this is a Rabbit... but the battery
terminals were already nice and clean (new one on the ground side) and I got
all the extra ground wires hooked on nicely... including the one that had
dissappeared under the fuel distributor... comes from ignition module... was
the original "no spark" culprit..., who knows what the lights are doing, no
horn either, so I got plenty to do. Oh yeah, and the stupid buzzer and oil
light was going off, too! False alarm, I'm sure... as I've seen this on
about a dozen Rabbits so far. Of course, I'll pipe up my oil pressure gauge
to be sure, then bypass it. SOOOOOOO, it's sure nice to know it will run
and drive before thinking about all the rest! Hopefully I'll at least have
it starting and yard driving easily before it snows!

(VW repairs... make for interesting conversation... if you got nuthin to
positive to contribute... just flame a Honda... )
In2hoppn

"dave AKA vwdoc1" > wrote in message
...
> I was going to say that you need to start with the basics.
> Make sure the timing belt is correct. I have seen sooo many that were
many
> notches off including my 1.8t engine when I bought it. Oh and it had good
> compression (150 psi) even for a low compression engine that was 4 notches
> off.
> Yes the engine could run but might not run at full power or might be hard
to
> start.
> Your compression, especially with Hyd Lifters, might be low until the
> lifters pump up and the engine is warm.
>
> THEN check the spark timing.
>
> CIS usually needs that cold start valve to spray a little fuel inside the
> intake manifold to make starting easier.
>
> Glad you got it started! ;-)
> Check out the main battery cable going to the starter and the main
negative
> cable to the engine.
> I suggest taking them off and cleaning all surfaces.
>
> JMHO
> --
> later,
> (One out of many daves)
>
>
> "In2hoppn" > wrote in message
> news:B4qdnb27NM8WvXvXnZ2dnUVZ_tWdnZ2d@metrocastcab levision.com...
> >I think hydrolic lifters play a role...
> > I did finally get it running. Had to pull it up the street. Runs good,
> > too. But still won't start by starter. It's just not cranking fast
> > enough.
> > The starter is just plain cooked and drawing way too much current. It's
> > cranking like about 1/2 speed... although my 83 will start at that speed
> > if
> > battery is half dead (like after sitting all winter). So apparently
it's
> > a
> > combination of slow starter and hard starting from the typical fuel
ratio
> > not ideal yet cis syndrome : ) I'm betting compression has come up
after
> > running it and building some oil pressure, but never did check it again.
> > It had a coolant leak as well, so for all I know it's been cooked a
bit...
> > maybe valve springs are weak now? I don't know, but it didn't want to
> > idle
> > and I didn't dare let it run too long with the coolant leaking (hose off
> > end
> > of head) so I didn't do anymore tinkering. But I did drive it around
the
> > yard and out back and it runs smooth and strong... and I at least know
now
> > that the clutch is good, as well as 1st, 2nd, and reverse gears... yard
> > too
> > small for 3rd, 4th, and 5th : )
> >
> >
> > "SFC" > wrote in message
> > ...
> >>
> >> If you realy measured "only" 55psi then it must be leaking through the
> >> valves. Normal value is between 140...180psi! Acc to vw it is due for
> >> overhaul when it is dropped to about 105psi! You'll never get it
started
> >> with almost no compression....
> >>
> >> First check what the cause is for that low cyl. pressure! If the oil
> >> trick
> >> didn't make a difference then it must be bad valves or a very bad head
> >> gasket (unlikely)
> >>
> >> SFC
> >>
> >>
> >
> >
>
>