1990 corrado fuel system... how does it meter the fuel??

got this 1990 corrado...1.8... digifant?... supposedly WAS running this
way... supercharger has been removed and was running without it.
timing belt was quite slack and had jumped.
Replaced timing belt, aligned correctly (confirmed flywheel mark 0 is really
TDC) and distributor rotor directly at timing mark on distributor.
Started briefly, bog bog bog with throttle... couldn't get it fired up again
yet.
This was the extent that I ever saw this thing run before doing the timing
belt... bog bog bog and dead.
Not exactly sure where to go from here...
There is no hood sticker for timing specs. Not sure if base timing can be
left at tdc or what. I've tried moving the distributor since. It was
firing and kicking back on the starter at one point. Fired up a little here
and there.
I can't seem to find any information on how fuel metering is done on this
thing! It's not CIS, and there is no air door or anything except a temp
sensor / pot. in the boot to the throttle body...
Hoping someone can direct me to a good comprehensive site that shows how
this system is supposed to work, so I can hopefully figure out how to make
this thing run! It doesn't even have to run right... just be driveable /
moveable, as it's supposed to be heading for a VR6 transplant later...

Sounds like the timing belt was installed wrong! AND now the distributor is
timed wrong also.
The engine will be quite a bit slower without the Supercharger.
HOW did you set the camshaft timing?

http://vwrado.blogspot.com/
--
later,
(One out of many daves)


"In2hoppn" > wrote in message
news:-bidnUBaU4JDaHTVnZ2dnUVZ_hudnZ2d@metrocastcablevisi on.com...
> got this 1990 corrado...1.8... digifant?... supposedly WAS running this
> way... supercharger has been removed and was running without it.
> timing belt was quite slack and had jumped.
> Replaced timing belt, aligned correctly (confirmed flywheel mark 0 is
> really
> TDC) and distributor rotor directly at timing mark on distributor.
> Started briefly, bog bog bog with throttle... couldn't get it fired up
> again
> yet.
> This was the extent that I ever saw this thing run before doing the timing
> belt... bog bog bog and dead.
> Not exactly sure where to go from here...
> There is no hood sticker for timing specs. Not sure if base timing can be
> left at tdc or what. I've tried moving the distributor since. It was
> firing and kicking back on the starter at one point. Fired up a little
> here
> and there.
> I can't seem to find any information on how fuel metering is done on this
> thing! It's not CIS, and there is no air door or anything except a temp
> sensor / pot. in the boot to the throttle body...
> Hoping someone can direct me to a good comprehensive site that shows how
> this system is supposed to work, so I can hopefully figure out how to make
> this thing run! It doesn't even have to run right... just be driveable /
> moveable, as it's supposed to be heading for a VR6 transplant later...
>
>

Timing belt dead on... did it myself... same as any other 8 valve 1.8 I've
ever done... cam sprocket mark at front edge of valve cover, intermediate
shaft mark at edge of crank v belt pulley, crank at cylinder 1 piston top of
stroke (and flywheel zero mark is also correct... sometime they are not so I
always check by piston). Distributor was already loose (this whole car is a
hack job throw together to begin with, body and mechanicals) so I just
brought that around to align the mark with the rotor (will put that back
again this morning).

Also, meant to add to post... I've checked grounds and power at ECU.
Coolant temp ohms was at 3400. Ambient air temp was at about 56F so I guess
that's not too far off if at all? Also, I did find the 02 sensor unplugged.
Dirty plug but clean where it joins, so I think it was recently unplugged so
I tried plugging it back together.

So... question... is distributor supposed to be set at zero? Because that's
where I'm putting it back to for now.

And I'm definitely looking for info on how this fuel system works! I think
wrong mixture is the bulk of the problem to begin with. Owner had already
messed with timing and figured out timing belt needed replacing. It was
quite slack and worn. I never confirmed it actually jumped, just changed it
out and set it right with a new tensioner. That's what I was told to do...
but it still don't run. If I can figure it out and make it run pretty soon,
that will be great. Otherwise, it get's hauled back to him.

"dave AKA vwdoc1" > wrote in message
...
> Sounds like the timing belt was installed wrong! AND now the distributor
is
> timed wrong also.
> The engine will be quite a bit slower without the Supercharger.
> HOW did you set the camshaft timing?
>
> http://vwrado.blogspot.com/
> --
> later,
> (One out of many daves)
>
>
> "In2hoppn" > wrote in message
> news:-bidnUBaU4JDaHTVnZ2dnUVZ_hudnZ2d@metrocastcablevisi on.com...
> > got this 1990 corrado...1.8... digifant?... supposedly WAS running this
> > way... supercharger has been removed and was running without it.
> > timing belt was quite slack and had jumped.
> > Replaced timing belt, aligned correctly (confirmed flywheel mark 0 is
> > really
> > TDC) and distributor rotor directly at timing mark on distributor.
> > Started briefly, bog bog bog with throttle... couldn't get it fired up
> > again
> > yet.
> > This was the extent that I ever saw this thing run before doing the
timing
> > belt... bog bog bog and dead.
> > Not exactly sure where to go from here...
> > There is no hood sticker for timing specs. Not sure if base timing can
be
> > left at tdc or what. I've tried moving the distributor since. It was
> > firing and kicking back on the starter at one point. Fired up a little
> > here
> > and there.
> > I can't seem to find any information on how fuel metering is done on
this
> > thing! It's not CIS, and there is no air door or anything except a temp
> > sensor / pot. in the boot to the throttle body...
> > Hoping someone can direct me to a good comprehensive site that shows how
> > this system is supposed to work, so I can hopefully figure out how to
make
> > this thing run! It doesn't even have to run right... just be driveable
/
> > moveable, as it's supposed to be heading for a VR6 transplant later...
> >
> >
>
>

Also should have added... fuel pump runs... haven't checked pressure, not
sure where I need to hook in to do that yet and if I have the fittings to do
so. Thinking I might disconnect the fuel pump to prevent flooding and check
spark a little better than with just timing light! But plugs, wires, cap,
rotor, all look new and not damaged. Might even try a little starting
fluid... a little, just to see if it fires up. If I still have a can of
that somewhere! Then I'll focus on fuel delivery. The guy just bought this
thing. Who knows what's in the tank, but it smells like gas : ). Thanks
again for any and all input!

"dave AKA vwdoc1" > wrote in message
...
> Sounds like the timing belt was installed wrong! AND now the distributor
is
> timed wrong also.
> The engine will be quite a bit slower without the Supercharger.
> HOW did you set the camshaft timing?
>
> http://vwrado.blogspot.com/
> --
> later,
> (One out of many daves)
>
>
> "In2hoppn" > wrote in message
> news:-bidnUBaU4JDaHTVnZ2dnUVZ_hudnZ2d@metrocastcablevisi on.com...
> > got this 1990 corrado...1.8... digifant?... supposedly WAS running this
> > way... supercharger has been removed and was running without it.
> > timing belt was quite slack and had jumped.
> > Replaced timing belt, aligned correctly (confirmed flywheel mark 0 is
> > really
> > TDC) and distributor rotor directly at timing mark on distributor.
> > Started briefly, bog bog bog with throttle... couldn't get it fired up
> > again
> > yet.
> > This was the extent that I ever saw this thing run before doing the
timing
> > belt... bog bog bog and dead.
> > Not exactly sure where to go from here...
> > There is no hood sticker for timing specs. Not sure if base timing can
be
> > left at tdc or what. I've tried moving the distributor since. It was
> > firing and kicking back on the starter at one point. Fired up a little
> > here
> > and there.
> > I can't seem to find any information on how fuel metering is done on
this
> > thing! It's not CIS, and there is no air door or anything except a temp
> > sensor / pot. in the boot to the throttle body...
> > Hoping someone can direct me to a good comprehensive site that shows how
> > this system is supposed to work, so I can hopefully figure out how to
make
> > this thing run! It doesn't even have to run right... just be driveable
/
> > moveable, as it's supposed to be heading for a VR6 transplant later...
> >
> >
>
>

Make sure the plug wires are installed correctly. Often people switch
2 wires or more. Have someone else operate starter while you aim
timing light so you know at least one plug is firing at either the
correct spot or 180 degrees out. Or is it 360 degrees out as it fires
once every two revolutions?

On Mon, 6 Oct 2008 08:18:48 -0400, "In2hoppn" >
wrote:

>Also should have added... fuel pump runs... haven't checked pressure, not
>sure where I need to hook in to do that yet and if I have the fittings to do
>so. Thinking I might disconnect the fuel pump to prevent flooding and check
>spark a little better than with just timing light! But plugs, wires, cap,
>rotor, all look new and not damaged. Might even try a little starting
>fluid... a little, just to see if it fires up. If I still have a can of
>that somewhere! Then I'll focus on fuel delivery. The guy just bought this
>thing. Who knows what's in the tank, but it smells like gas : ). Thanks
>again for any and all input!
>
>"dave AKA vwdoc1" > wrote in message
...
>> Sounds like the timing belt was installed wrong! AND now the distributor
>is
>> timed wrong also.
>> The engine will be quite a bit slower without the Supercharger.
>> HOW did you set the camshaft timing?
>>
>> http://vwrado.blogspot.com/
>> --
>> later,
>> (One out of many daves)
>>
>>
>> "In2hoppn" > wrote in message
>> news:-bidnUBaU4JDaHTVnZ2dnUVZ_hudnZ2d@metrocastcablevisi on.com...
>> > got this 1990 corrado...1.8... digifant?... supposedly WAS running this
>> > way... supercharger has been removed and was running without it.
>> > timing belt was quite slack and had jumped.
>> > Replaced timing belt, aligned correctly (confirmed flywheel mark 0 is
>> > really
>> > TDC) and distributor rotor directly at timing mark on distributor.
>> > Started briefly, bog bog bog with throttle... couldn't get it fired up
>> > again
>> > yet.
>> > This was the extent that I ever saw this thing run before doing the
>timing
>> > belt... bog bog bog and dead.
>> > Not exactly sure where to go from here...
>> > There is no hood sticker for timing specs. Not sure if base timing can
>be
>> > left at tdc or what. I've tried moving the distributor since. It was
>> > firing and kicking back on the starter at one point. Fired up a little
>> > here
>> > and there.
>> > I can't seem to find any information on how fuel metering is done on
>this
>> > thing! It's not CIS, and there is no air door or anything except a temp
>> > sensor / pot. in the boot to the throttle body...
>> > Hoping someone can direct me to a good comprehensive site that shows how
>> > this system is supposed to work, so I can hopefully figure out how to
>make
>> > this thing run! It doesn't even have to run right... just be driveable
>/
>> > moveable, as it's supposed to be heading for a VR6 transplant later...
>> >
>> >
>>
>>
>

"In2hoppn" > wrote:

>got this 1990 corrado...1.8... digifant?... supposedly WAS running this
>way... supercharger has been removed and was running without it.
>timing belt was quite slack and had jumped.

>Replaced timing belt, aligned correctly (confirmed flywheel mark 0
>is really TDC) and distributor rotor directly at timing mark on
>distributor. Started briefly, bog bog bog with throttle...
>couldn't get it fired up again yet.

>This was the extent that I ever saw this thing run before doing the
>timing belt... bog bog bog and dead.
>Not exactly sure where to go from here...

>There is no hood sticker for timing specs. Not sure if base timing
>can be left at tdc or what. I've tried moving the distributor
>since. It was firing and kicking back on the starter at one point.
>Fired up a little here and there.

Timing with Digifant is usually set at around 2400 rpm.
Coolant temp sensor disconnected. 6 +/-1 degrees BTDC.

Borrow a workshop manual.

Remove and read the spark plugs.

>I can't seem to find any information on how fuel metering is done
>on this thing! It's not CIS, and there is no air door or anything
>except a temp sensor / pot. in the boot to the throttle body...

Digifant with supercharged engines (G40 and G60) uses a manifold
absolute pressure (MAP) sensor. The sensor is in the ECU box.
There's a pressure line (rigid plastic tube) between the manifold
and the ECU. The system is very sensitive to manifold pressure and
any leak will frustrate reliability.

Removing the supercharger messes up the whole air delivery system
as the idle stabiliser valve also acts as a boost bypass valve.

It's quite likely that Digifant has switched to limp-home mode as no
boost is being made. The car will run, but significantly worse than
a normal, 8-valve GTI.
--
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | Science is the belief in
X against HTML mail | the ignorance of the experts.
/ \ and postings | -- Richard Feynman

You can set the static timing at 8 deg btdc. There's a mark for that on the
flywheel. The distrb. finger should then point to cyl 1. This engine is not
sensitive in terms of timing any thing between 0 and 8 will work.
The fuel system is based on speed density so no airmeter just a pressure
sensor inside the ecu and a air temp. sensor in the tube going to the
throttle housing. The air temp sensor is combined with a CO pot. With this
CO pot you can adjust the mixture to correct the CO value. The pot is behind
that blue plug.
Be aware that there are two marks on the cam sprocket. Use the one on the
valve cover side no the outer.
Don't worry about the supercharger and the ISV. They won't have any affect
on the basic running of the engine. The ISV is only used to bleed of too
much boost but without the charger there isn't any. Resistance of the cool
temp sensor is normal for that temp. If you want to check fuel pressure you
can disconnect the line going to the fuel pressure sensor on the other end
of the fuel rail. This fp.sensor is used for the after run system to avoid
vapour lock.
No limp home mode. It's actually a very simple engine/computer.
This engine won't produce much hp with some boost, CR is only 8:1.

SFC

"SFC" > wrote in message
.. .
> You can set the static timing at 8 deg btdc. There's a mark for that on
the
> flywheel. The distrb. finger should then point to cyl 1. This engine is
not
> sensitive in terms of timing any thing between 0 and 8 will work.

Thanks, I'll look for that mark and set it there!

> The fuel system is based on speed density so no airmeter just a pressure
> sensor inside the ecu and a air temp. sensor in the tube going to the
> throttle housing.

It's there. Just though of checking my Vantage meter for some specs for
that! Not sure if I have that coveraged... and it sounds pretty crucial to
be not too far out of range.

>The air temp sensor is combined with a CO pot. With this
> CO pot you can adjust the mixture to correct the CO value. The pot is
behind
> that blue plug.

Is the range enough to make it not run?? The blue plug is still in so
hopefully nobody's messed with it!

> Be aware that there are two marks on the cam sprocket. Use the one on the
> valve cover side no the outer.

Yes! Actually there are 3 marks. 2 outside and 1 inside. The 2 outside
ones mark the 2 teeth that the inner one resides between. Very handy to
locate it initially... but still a pain to sight for correct alignment, but
it's correct.


> Don't worry about the supercharger and the ISV. They won't have any affect
> on the basic running of the engine. The ISV is only used to bleed of too
> much boost but without the charger there isn't any. Resistance of the cool
> temp sensor is normal for that temp. If you want to check fuel pressure
you
> can disconnect the line going to the fuel pressure sensor on the other end
> of the fuel rail. This fp.sensor is used for the after run system to avoid
> vapour lock.
> No limp home mode. It's actually a very simple engine/computer.
> This engine won't produce much hp with some boost, CR is only 8:1.

Gee, sounds like maybe it should run every bit as good if not better than a
stock 1.7 8V then??
I guess there's not much excuse for me to not be able to make thing run
again... not know what the heck I'm doing is a good reason but poor excuse
: ). Thanks MUCH!
In2

Well trying to set cam and flywheel back to zero to reset distributor
yeilded no mark at flywheel? WHAT?? I KNOW I had this right (and it was
much easier to turn everything by the crank when the alt belt / tensioner
and pulley were all out of the way!)...

Remove plugs (sure takes the load off trying to turn it over by the cam).
Bringing her around and piston coming up. Then piston stops for about an
8th turn. Then continues coming up! Seems somebody put the sprocket on the
crank minus a key? ...or somethings gotten munched?? Never seen this
before!

I used to say the intermittents were the worse mechanics nightmare. Now I
move it to 2nd, with working behind someone elses work to 1st place! Now I
can take it all back apart and see what someone has done to this poor thing!
All I can say is it's a good thing it's an 8V non-interference... will
finish the story later if it ever ends... : )

In2hoppn (former bad rabbit habit)

On Oct 6, 1:27*pm, "In2hoppn" > wrote:
> Well trying to set cam and flywheel back to zero to reset distributor
> yeilded no mark at flywheel? *WHAT?? *I KNOW I had this right (and it was
> much easier to turn everything by the crank when the alt belt / tensioner
> and pulley were all out of the way!)...
>
> Remove plugs (sure takes the load off trying to turn it over by the cam).
> Bringing her around and piston coming up. *Then piston stops for about an
> 8th turn. *Then continues coming up! *Seems somebody put the sprocket on the
> crank minus a key? ...or somethings gotten munched?? *Never seen this
> before!
>
> I used to say the intermittents were the worse mechanics nightmare. *Now I
> move it to 2nd, with working behind someone elses work to 1st place! *Now I
> can take it all back apart and see what someone has done to this poor thing!
> All I can say is it's a good thing it's an 8V non-interference... *will
> finish the story later if it ever ends... : )
>
> In2hoppn (former bad rabbit habit)

Check the woodruff key in the crank for the timing belt sprocket, I
had a friend with a G60 that sheared that key off with similar
results. I've got another G60 in my garage that I suspect the same
thing happened to, but I have no time to mess with the @#$%^ POS.

nate