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-   -   I rebuild engine but it doesn't start, help !!! (http://forums.pelicanparts.com/porsche-911-technical-forum/598199-i-rebuild-engine-but-doesnt-start-help.html)

calling911 03-25-2011 01:48 PM

Popcorn is in the microwave... I wanna hear it start! :)

Im excited and its not even my car! :)

EDIT: when it "coughs" is it coughing into the intake or the exhaust? Enquiring minds want to know!

I've done the 180 thing on a VW Rabbit.. VERY LOUD pops in the intake..

Flat6pac 03-25-2011 06:14 PM

This is a 3.0 distributor and it does turn counter clock wise. I m showing the relationship of the rotor to the edge of the distributor. You need to check the #1 intake valve to see if its loose.
You need to set it up the way the book sets it up. You cant have your plug wires start anywhere on the cap, there is a complete relationship the book instructs you on.
Yon need to acertain TDC. Almost right will run but not well. Each cog on the bottom of the distributor represents 30 degrees. If youre 1 cog off it will run but with difficulty.
Bruce
http://forums.pelicanparts.com/uploa...1301105646.jpg

930cab89 03-26-2011 10:48 AM

Ok so now the distributor is ok, I'm pretty sure about that. I did what Moneymanager suggested: unscrewed #1 plug about 7/8 of the way and I heard the air come out & yields a sound you can hear when you turn motor clockwise to the firing point on #1 cylinder. Then I aligned the Z1 mark and put the distributor in place with the rotor facing the small groove. I also made sur that the rotor was right in front of the contact for cylinder 1 in the cap. This put the distributor in exactely the same location as before rebuilding the engine (I took pictures and notes).
Now when starting, the coughing and bangs are gone but the engine still does not run well. In fact, it dies after running about 2 seconds. Then if I try to restart it immediately, it won't start. If I wait a few minutes, I'm able to start it again for 2 seconds (during those 2 seconds, it runs fine). So I'm really suspecting the CIS now. What can I do to debug the CIS? Is there a way to check what's going wrong? Something I can bypass or do?
Thanks for your help.

calling911 03-26-2011 12:16 PM

Ok.. so HUGE improvement.. from what I read.. you are now starting!

So the delay indicates to me that maybe you are flooding? You know you pump is running now.. your mixture is going to be WAY off potentially with the new motor.. do you have an allen tool to do the adjustment? You KNOW you have spark..

I would lean it out 1/4 turn and see if it changes the situation.. if it doesnt start at all then go back 1/8 turn at a time.. but try and start it a few times between each adjustment..

I suppose your timing could still be off too.. so maybe tweak that slightly in each direction and listen...

this is what I would do anyway..

moneymanager 03-26-2011 12:19 PM

Well that's progress.
CIS has a lot of moving parts, especially the later ones with all the add-ons to fix basic design/operational problems. If the car ran decently before you pulled it apart, it's more likely that something you removed got replaced wrong, or you have a big vacuum leak or a bad connection, than it is that the startup valve died on the bench while waiting to be reinstalled. So go over everything you touched or moved with a fine tooth comb before doing anything else.

calling911 03-26-2011 12:22 PM

Quote:

Originally Posted by moneymanager (Post 5925692)
Well that's progress.
CIS has a lot of moving parts, especially the later ones with all the add-ons to fix basic design/operational problems. If the car ran decently before you pulled it apart, it's more likely that something you removed got replaced wrong, or you have a big vacuum leak or a bad connection, than it is that the startup valve died on the bench while waiting to be reinstalled. So go over everything you touched or moved with a fine tooth comb before doing anything else.

He could have had a bad vacum leak and the car was running fine.... so he needs to adjust the mixture.. and certainly crank the idle up for now 1/2 turn... you screw it OUT to make it go higher...

moneymanager 03-26-2011 12:35 PM

Sure... an easy thing to check.

calling911 03-26-2011 12:39 PM

You really want it to idle high when it starts anyway.. go 1 turn out.. I dont know what proper run in RPM is and for how long but you should know this before you proceed.. once it starts I think you want to run it for like 15 min or something like that at like oh say 2000 rpm.. something like that.. as I say.. I dont know the actual info..

But I really think you are rich... thats what it sounds like to me.. I can make my car do the same thing.

Flat6pac 03-26-2011 12:41 PM

You should be able to get a timing light on the pulley for a 2 second run if someone is turning the key.
Are the pumps running with the key on? or just when you move the air sensor.
Bruce

calling911 03-26-2011 12:45 PM

Quote:

Originally Posted by Flat6pac (Post 5925735)
You should be able to get a timing light on the pulley for a 2 second run if someone is turning the key.
Are the pumps running with the key on? or just when you move the air sensor.
Bruce


I think he is running the pumps manually based on a previous message.. even if his ignition timing is off its popping so it should run I think... I think his mixture is off.. although advancing it if retarded might help some....

This is just a 30 min tweak game he needs to play.

930cab89 03-27-2011 10:09 AM

Turning the mixture screw along with setting the idle higher changed nothing. The car still runs for 1 or 2 seconds and then dies. I pulled an injector out and no gas comes out so I think I've at least found that there is a gas shortage. But why? Also, when trying to start the engine without the intercooler in place, there was a big cough in the intake with a 10 cm flame coming out of the hole in which the intercooler goes on the injection. What does this indicate?

kodioneill 03-27-2011 11:04 AM

The intercooler has to be in place to start the car.

Tinker 03-27-2011 11:10 AM

As others have suggested, my guess is a vacuum leak.

Tinker

930cab89 03-28-2011 09:58 AM

Could it be that the fuel distributor is clogged and that the engine only starts and runs for 2 seconds by making use of the cold start device? The car hasn't run for 5 months now.

brads911sc 03-28-2011 12:50 PM

could be a variety of things. I would thoroughly clean and test as many of the CIS components that you can find. Have you checked your cold pressures?

930cab89 03-28-2011 10:51 PM

I will take the car to a Porsche specialist next week, I have had enough of it. Thanks for all the help and support.

cdrik915 03-28-2011 11:28 PM

Verifie ton distributeur , c'est lui en cause , a tous les coups.

J'ai deja eu cette panne sur une sc. (Neil)


Amities,


Ced'

930cab89 03-30-2011 11:10 PM

Hi Cedric, I've checked and rechecked the position of the distributor many times and I'm pretty sure it's ok now. I'll know more next week.

cdrik915 03-30-2011 11:25 PM

No , i talk about the gazoline distributor.

930cab89 04-20-2011 01:33 AM

Just to keep you informed: SHE HAS STARTED AND RUNS FINE !!!!!!!!!!!!!!!!!!!!!!!

In fact, it was a relatively simple problem (as always afterwards). I've changed the gaskets of the intercooler and it was relatively difficult to put it in place with those new gaskets. I didn't really bother as I thought it would just start, intercooler in place or not. WRONG ! The intercooler helps create (from what I've understood) a depression in the intake that helps move the metering plate which in turn activates the switch that's located near it and that meters the flow of gas. As the intercooler was not correctly positioned, there was not enough depression and the metering plate didn't move. As soon as my wrench corrected this, VROUM she went! By the way, after all these tries, my distributor was ok (and all the other things I've done on the engine). I can look at myself in the mirror again ;-)

Thanks for all the support.


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