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-   -   Cannot startup after rebuild (http://forums.pelicanparts.com/porsche-911-technical-forum/595233-cannot-startup-after-rebuild.html)

SorenDK 03-05-2011 01:46 PM

Cannot startup after rebuild
 
I'm frustrated here and hope that someone can guide me in the right direction...

The problem is that I cannot startup the engine after a rebuild - its a 2 liter E from 1969 fitted with Webers.

The ignition setup in short:
Crane XR700 optical ignition.
Blue bosch coil

The problem is that I cannot fire her up... cranking the starter producers the eventual firing or 2 in the odd cylinder but nothing consistent. Have been testing the coil and plugs. I have checked the coil for spark and it sparks but not only about 1 cm or so.

The plugs fires too but I dont know if the spark is strong enough to fire up.

The carbs is pretty much a mystery in it self... :-) - I have setup the Webers to the basic settings expecting a tune up when the damn thing starts :-)

Problems/questions

What are my options to improve ignition/spark power?
Is there any known problem areas with crane xr 700's?
The carbs are spitting...? Spitting probably means the carbs are lean - but I cant even start her up?? - they spits when cranking the starter..?? how to remedy this? - my startup settings are:
Idle mix: 5 half turns from light seated
Air: 1 half turn from light seat
Idle - barely touching ...

What would you do in my place? :-)


Thanks

mpetry 03-05-2011 02:17 PM

A lot of variables in this question, so I'll just toss this out there and see where it goes.

Are you sure the ignition timing is set properly ? Or even close? Since you need a running engine to use a timing light, why don't you try static timing it. This is an old trick from VW land.

Get a light bulb - a tail light bulb will do - and solder on 2 clip leads. Connect one to the cold side of the coil and the other to any convenient ground on the motor.

http://www.petry.org/pics/staticlite.jpg

Set the engine to 20 degrees before top dead center (Z1 mark to the LEFT of the case index mark)

Turn key to position 1 (Run not start).

Now slowly rotate the engine thru TDC, clockwise, using the fan pulley nut. (note, this is a 912 picture, but the idea is the same)

http://www.petry.org/pics/statictiming.jpg

Does the light go on at "about" TDC or shortly before ?

Adjust the distributor, roll the engine backwards, and try again. You want to set the timing - initially - to about 3-5 deg BTDC. At this setting you should be able to start it.

This procedure will get the timing in the ballpark so you can start the engine. I'm assuming all the grounds and stuff are OK.

Flat6pac 03-05-2011 02:31 PM

I d go to the Bosch CD, the set of points, and a 001 Bosch black amplifier (coil).
Pull the left valve cover, at Z1 make sure your intake rocker is loose and not on the intake stroke.
Make sure your rotor is coming up on the notch in the distributor to TDC

snbush67 03-05-2011 08:44 PM

Fresh Fuel?
Fuel Pressure (4-5lbs)?
Check the plugs are they wet? Too much fuel?
Turn your idle stop screws to touching and then 1/4 turn more.

Shane

SorenDK 03-06-2011 09:29 AM

Brillilant guys... thanks Mark for the very good description. I think the Webers are letting me down big time. The plugs are wet and fuel is even pouring through the manifold and out so its really being flushed.
I am removing the carbs to go through them again with extra attention to details - dont want to flush the cylinders more...

I'll let you know when she's running... thanks again... :-)

tompowers 03-07-2011 07:11 PM

I bet it is the webers. Take each and everything out and inspect and clean (slowly, one piece at a time). How long did those carbs sit? I had the exact same problem when I did the 1600 motor on my '67 Alfa Duetto. Finished it up and it would NOT run. Pulled my hair out over timing, spark strength, coil, went to an electronic ignition, put an adjustable fuel pressure regulator in it, (someone correct me, but the webers crave 3 lbs.) etc. etc. I was convinced I botched the motor work. In the end, it was the carbs.... the third time I disassembled and cleaned them did the trick. Boy, it runs great.

T77911S 03-08-2011 09:53 AM

Quote:

Originally Posted by Flat6pac (Post 5883994)
I d go to the Bosch CD, the set of points, and a 001 Bosch black amplifier (coil).
Pull the left valve cover, at Z1 make sure your intake rocker is loose and not on the intake stroke.
Make sure your rotor is coming up on the notch in the distributor to TDC

this is what i was thinking. take out the unknown and put in something basic that you know will work. make sure things are not 180 out and that the firing order is correct.
then i would turn to what sounds like the major problem, the carbs. get it running with the basic ignition, tune the carbs, then put the other (ill be nice) stuff back on.

5 turns out! wow!
carbs require a lot to get them working right. starting with good clean carbs that dont leak air. then fuel pressure, floats, initial settings. dont get me wrong, i love them, but unless they are "perfect" they are a lot of work and dont wrok right.

here is a good site for carbs

Performance Oriented

snbush67 03-08-2011 10:05 AM

T77 "5 half turns from light seated" that is 2 1/2 turns out. I thought the same thing when I first read it.

Shane

E Sully 03-08-2011 01:45 PM

Make sure to air out the cylinders to get rid of the excess fuel, hydrolock can do a lot of damage. It could also contaminate the oil. You might want to change it.

Zeke 03-08-2011 03:57 PM

Disconnect the fuel pump and use some starter fluid and see if it runs for a few seconds. If so, you have spark in the right order and you can blame the carbs.

The thing is, you have to quit fooling around because the cams need the 20 minute break-in, not a bunch of quick starts and stops.

SorenDK 04-04-2011 01:36 PM

Got her fired up... not really sure what was wrong to be honest... I just started all over again... basically resetting ignition and carbs and went through all the wiring again and suddenly she fired up on all cyls... smoked like hell though... :-)
Oil pressure is perfect and I got her warmed up and breaked-in on the safe side...

YouTube - First start in 20 years... Porsche 911E from 1969

Its quite amazing imaging that this engine has not run in 20 years and yet it sounds beautiful... disregarding the lack of adjustment of carbs and timing of course...

Thanks guys for all your help...

My next issue is the tach+crane... does anyone know how the tach is connected to a crane xr700?... keep in mind a have a 1969E. I suspect the black/purple wire from tach goes directly on (-) coil?
Also do I need a ballast resistor on my blue bosch coil in order not to fry the crane unit? BTW its a plain simple Bosch distributor??

jimbauman 04-04-2011 02:25 PM

Just saw the video - what a sweet looking car - sounds great and LOVE the color!!

JB

jpnovak 04-04-2011 02:26 PM

connect the black/purple wire to the white wire from the XR700.

DO NOT CONNECT IT TO THE COIL.

Do you still have the CDI unit? Is the XR700 connected to use the optical trigger for the CDI or has it been installed as a replacement for the CDI?

For reference, The 69 911E should have points triggering the CDI.

SorenDK 04-04-2011 09:31 PM

Thanks... Yup good Ole bahama gelb is nice...;-)

My setup is this... Crane unit is replacing the CDI - optical ign is replacing points so the flow is from dist. to crane to coil and finally to cyls.

Any knowledge about a ballast resistor ? No visible evidence that one was installed from PO...!

Thanks...

T77911S 04-05-2011 03:00 AM

go back to the original CD and dist and just get it running, then change out the ignition.

SorenDK 04-05-2011 04:36 AM

T77... i did get it running - and i think it goes OK considering the total lack of adjustment :-) so I would not go back to points etc. now. The ignition is fine so far. My concern is twofold:

1) Frying the Crane unit not installing a ballast resistor
2) Frying the tach ... however the solution seems to be to connect the black/purple to the white wire from the Crane unit.

Jamie... do you know about the ballast resistor?


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