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-   -   Rebuilt Carrera motor trying to start but not quite making it (http://forums.pelicanparts.com/porsche-911-technical-forum/385087-rebuilt-carrera-motor-trying-start-but-not-quite-making.html)

preston_brown 01-01-2008 05:18 PM

Rebuilt Carrera motor started for first time!
 
I got my freshly rebuilt Carrera motor installed on Sunday, and today I hooked up the last of the connections and tried to fire it up. I cranked w/o the DME or plugs at first to build oil pressure and check for leaks, it built healthy oil pressure. Next I put in the DME relay and cranked for 15-20 seconds to check for gas line leaks, I can't see any. I put in the plugs and hooked up the wires, and it sounds like it is trying to start but it just can't quite make it. I've cranked it maybe 10 times for 10-20 seconds each time. I've got spark and fuel -- at least to the rails. Maybe I have an injector issue? What does it sound like to the experts?

Looking forward to having my car back on the road.

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Thanks for any ideas.

john walker's workshop 01-01-2008 06:11 PM

got the FI plug plugged in, by the top of the left shock? got the black plugs swapped for the crank sensors? got the plug wires arranged 162435 in a clockwise direction?

preston_brown 01-01-2008 07:13 PM

The motor wasn't even attempting to fire when I swapped the speed and reference sensors for the crank. With the way they are now, at least you can hear it trying to catch. The FI plug (assume it is the multi-pin connector on the front of the motor) is plugged in. Plug wires are properly arranged and are all getting spark to at least the ends of the wires - tested each one with a spare plug.

rsscotty 01-01-2008 07:26 PM

There are two multi pin plugs....a 14 pin by the left rear and a 6 pin on the shock tower x mbr. left side of engine.

Wayne 962 01-01-2008 09:37 PM

I'll bet 99% your plug wires are swapped incorrectly. Check them, check them again, and then check them one more time. I had this problem once - third time I checked the wires, I noticed that a few were switched. Very easy mistake to make...

-Wayne

ChrisBennet 01-02-2008 05:12 AM

Quote:

Originally Posted by Wayne at Pelican Parts (Post 3677635)
I'll bet 99% your plug wires are swapped incorrectly. Check them, check them again, and then check them one more time. I had this problem once - third time I checked the wires, I noticed that a few were switched. Very easy mistake to make...

-Wayne

It takes a big man to admit that. LOL.
Yeah, BTDT. When I did it, it was accompanied by loud backfires.
-Chris

mb911 01-02-2008 05:40 AM

Quote:

Originally Posted by Wayne at Pelican Parts (Post 3677635)
I'll bet 99% your plug wires are swapped incorrectly. Check them, check them again, and then check them one more time. I had this problem once - third time I checked the wires, I noticed that a few were switched. Very easy mistake to make...

-Wayne

100% agreed same thing has happened to me a couple of times in the past as well.

ischmitz 01-02-2008 05:41 AM

And then there are all these stories with stuck injectors after they have been sitting for some time. Do a search. There were several examples recently where the engine ran on less than 6 barrels....

911 tweaks 01-02-2008 05:45 AM

dumb question... how much "NEW" gas did you put in the tank? If tank has old gas, that will be an issue.
If tank emptied and you added 2,3 or 4 gallons, I believe it takes ~ 2 gallons to fill the fuel filter, lines, purge out all the air in injectors... AND your fuel pump may be lazy/partial working. Put in 10 gals of NEW gas.
Sounds simple but you would be suprised how often this is thought of as, ... yea I put 3-4 gals in and that is enough to get it to fire... probably NOT!
I am interested to hear what you find. You are almost there!!
Bob

JeremyD 01-02-2008 05:58 AM

I'd check Ed's thread - rebuilt injectors don't like sitting - little tap of the hammer and a 9v battery can test em and free them up.

I had my distributor at 180 degrees out of whack - and two plugs swapped.

preston_brown 01-02-2008 06:13 AM

Both multi-pin plugs are correctly inserted. The tank did have old gas, about 10 gallons worth. I haven't put any new gas in. I am sure that the old gas isn't totally helping but at the same time I don't think its the problem. I'll double check plug wires this morning (though I've done that already twice) and pull the injectors to test with a 9 volt and report back. I'm leaning towards an injector issue because I think spark is working OK.

john walker's workshop 01-02-2008 06:52 AM

got proper clearance on the flywheel sensors?

preston_brown 01-02-2008 09:03 AM

Success! It started.
 
It was the injectors. I tapped them all lightly with a small hammer and then it fired right up.

Here's the moment of triumph! Thanks again to all who have helped me out. I only see one very minor oil leak after 30 minutes, and that is at the joint of the hard oil line behind the motor and the large line to the thermostat. That was a bear of a line to remove for me initially and I may have slightly damaged the nut. One drop after my initial break-in.

The white stuff you can see flying around in the video is the packing from the M&K muffler flying out. It sure did eject a lot of the stuff. But it sounds good! You can also see a lot of oil and paint cooking off the motor. Smelled pretty crappy.

I'm off to change the oil and then take my first drive in almost a year. What a great New Year's present!

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mca 01-02-2008 11:08 AM

Congrats! I hope to be able to do the same thing to mine next year!

Did you rebuild yourself or did someone in NC do it?

peppy 01-02-2008 12:19 PM

Way to go!! This board is really a great help, I can't wait to get started on mine.

preston_brown 01-02-2008 09:21 PM

Quote:

Originally Posted by mca (Post 3678396)
Congrats! I hope to be able to do the same thing to mine next year!

Did you rebuild yourself or did someone in NC do it?

MCA:

I rebuilt it myself, with tips from everyone here on Pelican Parts BBS. Most of the rebuild threads are in the Engine Rebuilding forum. Here's a link to one of the threads:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/361688-carrera-3-2-top-end-rebuild-4.html#post3679679

ZOA NOM 01-02-2008 09:50 PM

Quote:

Originally Posted by preston_brown
I rebuilt it myself

Those words feel great rolling off the tongue, don't they.

Well done, Preston, and isn't it a great feeling of accomplishment and confidence? I felt like I could do anything when I finally fired up my rebuild. It is truly a life changing experience.

Welcome to the club :)

al lkosmal 01-02-2008 09:56 PM

Nothing like that feeling, when it 1st fires up.

preston_brown 01-03-2008 01:41 PM

I've got 60 miles on the car in the past two days, it's driving GREAT. No oil leaks...this can't be a real Porsche motor! I even fixed the little leak at the hard line junction at the rear of the motor by tightening it a bit more. When can I take it past 5000 RPM? Really now? I'm itching for redline.

mb911 01-03-2008 02:11 PM

Quote:

Originally Posted by preston_brown (Post 3678175)
It was the injectors. I tapped them all lightly with a small hammer and then it fired right up.

Here's the moment of triumph! Thanks again to all who have helped me out. I only see one very minor oil leak after 30 minutes, and that is at the joint of the hard oil line behind the motor and the large line to the thermostat. That was a bear of a line to remove for me initially and I may have slightly damaged the nut. One drop after my initial break-in.

The white stuff you can see flying around in the video is the packing from the M&K muffler flying out. It sure did eject a lot of the stuff. But it sounds good! You can also see a lot of oil and paint cooking off the motor. Smelled pretty crappy.

I'm off to change the oil and then take my first drive in almost a year. What a great New Year's present!

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/JVcrzDCkaS0"> </param> <embed src="http://www.youtube.com/v/JVcrzDCkaS0" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

Yours still had packing in it?? It must have been the last one we made like that Glad it is running well though

ZOA NOM 01-03-2008 03:00 PM

Quote:

Originally Posted by preston_brown (Post 3680867)
I've got 60 miles on the car in the past two days, it's driving GREAT. No oil leaks...this can't be a real Porsche motor! I even fixed the little leak at the hard line junction at the rear of the motor by tightening it a bit more. When can I take it past 5000 RPM? Really now? I'm itching for redline.


Check Wayne's rebuild book. In the back is a good procedure for breaking it in.

In general, I would say to "set" the moving parts with conservative RPM's for 50 miles or so, and then change the oil to the good stuff. Once that's done, warm it up and let her rip! With a properly lubricated motor, there is very little metal contact, as you well know from your teardown. Once rings have seated and seals are all snuggled in, she should be ready to run, and as we know, oil pressure rises with RPM, and higher pressure keeps the film of protection in place. It is the low pressure of idling in traffic that kills these motors.

paulgtr 01-03-2008 03:45 PM

my motor has never leaked.
knock on wood.
lol
just jinxed myself


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