I could have shot the bastard.....(long)

pookie · 10-30-2003, 02:55 PM

If my car were a dog I would have taken it out in the woods and shot it today. For those that don't know I have been having some issues with my car, to say the least. The car has had a irratic idle, and you cannot give the car any gas without it bogging down and cutting almost cutting out. But I thought today that I had them all sorted out. I finally got a chance to work on the car, I pulled the plugs and they looked a little light, so I figured I would richen up the mixture a little bit. I found on a previous post that my plugs were gapped too small for the MSD I have on my car, so I increased the gaps a little as well. I also checked for an unconnected hoses which may be causing a vaccum leak. After putting all the plugs back in and riching the mixture the idle smoothed out and the car ran. I mean really ran, I could give it gas in first gear, and I actually went for a 45 minute drive. I was in Porsche Nirvana. So I came home and parked the car. Wifey calls and asked me to run to the store to get some stuff for dinner. I am excited, figure I can go the long way and drive the car again. No such luck. I let the car sit for only 2 hours, when I went to go to the store all my old problems were back, irratic idle and if I tried to give it gas it only got bogged down an almost died. I couldn't even get out of the neighborhood. Its really weird, at idle you cannot even get the revs up without feathering the gas and catching the car just right, but as soon as you get the revs up and start moving, as long as you don't stop your ok. I am just about ready to give up. If any body has any suggestions, please let me know.
Thanks in advance
Ryan

Tim Walsh · Tim Walsh's Garage

Pookie,
I Have an MFI car so it might not be relevant but I had no compression on #6 and that was causing my erratic idle and lousy performance between 1K and 2K. For the 2 months I drove the car before the rebuild I just left my hand throttle up so it idled at 2K and I was ok.

pookie · 10-30-2003, 03:23 PM

I appreciate it Tim, but my car doesn't have a hand throttle. I guess what gets me is that it ran fine for when I took it out today, but after it sat it started acting up. I guess if it doesn't get sorted out I won't be making it on the NC fun run coming up. I hope ya'll have a blast though.
Ryan

john walker's workshop · 10-30-2003, 03:33 PM

you need to have the CO set on exhaust machine, to about 3.5%, first. do it hot. then let it get cold again, and see if it runs any better. if the bad running is just during the warm up period, for like 3 minutes or so, then the warmup regulator is likely running the engine too lean at first. they can be richened up by tapping the recessed pin down a few thousandths of an inch, which is tough to do precisely with a hammer and punch. usually you go too far, and the idle surges up and down. search WUR for the procedure. the WUR can also be erratic, where it changes it's control pressure all the time. in that case, replace it. a special CIS pressure gauge is used to check system and control pressures. pressure is the key to the whole system, so it needs to be correct.

sturco · 10-30-2003, 03:43 PM

Ryan, Is this a 3.0 SC setup ? The reason I ask, I went out cruising with my buddies this summer. One of the guys (79 911SC) had similar problems after a 2 hour ride. We had to push start the car to get it going etc. etc. When we got back he called one of our local mechanics who left Porsche about the time the SC run was over. He asked if anyone had ever put a drop of oil on the bottom of the distributor shaft or cap or something. According to him it was an absolute must on the SC setups that should be done when serviced. None of us had ever heard of this ! To make a long story shorter, the car now runs flawless. I don't know if this relates to your setup but it's something not written down anywhere. If you need the name of my buddy who had the work done, e-mail me direct and I'll get you his number also. Good luck, Steve. sturco1@twcny.rr.com

pookie · 10-31-2003, 05:06 AM

Mr Walker, thank you for the reply, could you tell me a little more about the CIS pressure gauge, and where I could get one?

Steve, I apprecitate the help and will send you an email when I get the chance.

I'm headed to the archives to look up the WUR. Any one know if there is a way to test the WUR? Hopefully it will be in the archives

Ryan

RickM · RickM's Garage

Possible vacuum issue?

Jdub · 10-31-2003, 07:21 AM

Ryan:

All the information on getting the pressure rig, etc. is in the archives: try a Search. Lots of information about this, specs, etc.

John

GenX Porsche · GenX Porsche's Garage

I had this exact same issue on my 1973.5 911t. I believe you have a CIS system since its an SC engine and if that is true these are my experiences. I took it to my wrench after it had all the same issues that you have described, rough idle and I couldnt give the car gas because it would bog down. His solution. The d@mn uber expensive fuel distributor. Mine had to be ordered from Germany. Apparently the little piston inside that setup is laser cut to a very fine tolerance. As you can image if that little piston gets stuck then it is going to get caught up and not return to its proper close position...ie its going to be continually dumping fuel into the cylinders even when you dont want to so when you push the gas in it actually adds to much gas and bogs down the engine. The test for this is that you pull the spark plugs, fire the engine to get all the fuel out of there, put the plugs back in and then go for a ride. It should run just fine but the second you turn off the car and try it again it wont work. It sounded like your car exhibited these characteristics. I hope my experience can help you get your car back on the road. You can e-mail me at David@thegravengroup.com or call me at (831)588-6010 if you need more info.
David

pookie · 10-31-2003, 04:43 PM

Thanks for all the replies guys...

GenX Porsche its weird that you mention the fuel distributer may be getting stuck. Before I actually drove the car the other day... I had whacked the fuel dist. a few times just out of pure frustration. Maybe that is what is wrong. I have to work for the next couple of days and won't get a chance to work on the car. I will check out all the suggestions and let you guys know what I find out.

Thanks
Ryan