Scott,

You can energize the FV relay (and FV) by doing the Fuel pump wire test we did Thursday. In the thread from last year we were trying to see if his car would die from other than the relay so we focused on how to cheat (bypass) the energizing part of the relay and take it out of the list of variables. - The energizing part of the relay is fed from pin 30 on the fuel pump relay.

For you, just do the red Fuel pump relay wire in the sockets exercise with the key on. Once the FP is buzzing, walk to the back of the car and grab or listen for the FV. If not working we can trouble shoot a much smaller list.

Either method will work - the FP method is way faster.

Bob, thanks. So form what I understand, I repeat the test I did thursday, but this time, i walk back to the engine and hold the fv, which should be buzzing/vibrating?

And just like on thursday, red relay removed and a single wire from 30 to 87a?

seems easy enough,
thanks for the help
scott

Determine the degree of your air leak/s........
 

Scott,

Not until you confirm the absence of a significant air leak/s in the system, we will all be guessing. It would take less than a minute to do the test after you applied a continuous supply of low pressure air into the system. I had posted pictures of the test several weeks ago in the technical forum. I would place my money on unmetered air as the culprit base from your description how the engine starts and stumble to die. This is a process of elimination and until it is tested, it would be my main suspect.

Tony

Alright, Ill get on this test first.

Thanks
Scott

tony, is this the thread that you put the pictures on?

http://forums.pelicanparts.com/porsche-911-technical-forum/622743-info-83-911sc-3-0l-back-dead-questions.html

if so, I get the general idea of the test (put soap everywhere where there possible could be an air leak) and pump in a little air and see where its blowing bubbles.

Where should I inject the air, and is there anything I need to plug up?

thanks
scott

Yep. Doubt it is the problem but let's get it out of the way.

I will let Tony answer the air input question. If you follow his instructions and you have time you may be driving the car real soon. Betcha!

Air leak detection in CIS........
 

Scott,

There is another post about where the injection could be made. If I recall correctly, Bob Contact asked that question too. BTW, I will send some pictures to your email. Remind me if you don't get them by tomorrow. Getting old too fast and forgets things.

Tony

Hello all,
Ive been busy and been doing some other work on the car (lowering to "euro height") since ive last visited this thread, or worked on the injection system. Anyways. I have the injection system out of the car, after finding it very hard to find the air leak with the system still in the car. I figure that if I seal everything off out of the car, than it should be easier because you can feel the whole thing on all sides for air, and dunk the airbox in water if needed.

Anyways, I am planning on doing that this weekend (testing for leaks), and I was wondering, say I take it into a shop to have them find and fix the leak (which I think it has been pretty much narrowed down to with the help of Tony and Bob), what do you think a reasonable price would be for them to charge. I havent had any work done on the car before, and hopefully I wont have to start now, but in case I cant find it. You always hear about everything Porsche, including repairs, costing a load, and I would like to know if I am getting ripped off or not. I would tell the shop first that I have already checked fuel pressure, so that should lessen the work load for them.

Thanks for the help everyone, I think I will have it back on the road soon
-Scott

Probably not what you want to hear, but it all depends on how long it takes them to find the leak(s). I had a situation like that last year when a customer brought me a car he could not get started. Only took me a half hour to find the root of the problem, but it took me another day and 1/2 to undo all his other mistakes and get the car running.

Haha, yeah, not what I was hoping for exactly. the local porsche guy said he could find it in about .5 to 1 hours and he charges $100/hr. After that, then comes the expensive part, I assume. EIther replacing parts, fixing parts, it will take time and money, and at a shop, time is money. So maybe if the fix seems doable, I could give it a try myself?

Hopefully I wont mess anything up.
-Scott

at a certain point, it would be cheaper to buy a new cis system used that was just pulled from a running car and put that in, which I could do without any trouble. and the way it looks right now, ill probably end up taking my car to the guy, hell find the problem, and then see whats the smartest thing to do from there depending on the problem.

thanks for the imput
scott

If he can find it for $100 that is money well spent. I would first go through the Tony test this weekend.

I agree with both statements there. I tried testing the injection on my car a couple weeks ago while on my car and found it to be very difficult. I couldnt find teh leak anywhere. today, i started testing it out of the car. THough I havent found a leak yet, if I were to find it, it would be out of the car IMHO. I have been blowing a lot of bubbles, and looking like a 3 year old while doing it, onto the injection system, a lot, so that some of the parts are getting coated with a thin layer of bubble juice, which I was thinking would start bubbling if it landed on the air leak.

I am going to try to reseal it more tightly, just to make sure Im not loosing much air though the bag or glove, though I dont think I was because the bag was pretty taut. http://forums.pelicanparts.com/uploa...1317426856.jpg
http://forums.pelicanparts.com/uploa...1317426867.jpg
http://forums.pelicanparts.com/uploa...1317426877.jpg
http://forums.pelicanparts.com/uploa...1317426891.jpg


Thanks for the help,
feedback appreciated
scott

just tested it again and i would pretty confidently say that there is no air leak.

That is good news.

I did the "full Tony" last week and found three leaks. Have to pull the air sensor off and replace the gasket.

You're making it too complicated.........
 

scott.k,

If I knew you would be taking the engine out, I would had advised you not to dismantle the CIS unit. What is important is checking the air leak/s when the unit is installed on the car. Just like I said before, it takes about a minute or less to do the test/inspection after you have injected low pressure air.

I wish you are closer so that we could test run the engine before putting it back. You have done a great job sorting the problem. Put them back together and repeat the same test.

Feel free to PM me or Bob. There's no need to buy any other CIS unit unless yours is bad or defective. This is not that complicated as you think!!!! You are doing very good than most other CIS troubleshooters I know in this forum. You'll be an inspiration to others and would assist you all the way.

Tony

Thanks for the encouragement and feedback!
I will give it another test tomorrow, I put the unit back in tonight. I will see how that goes and proceed from there. Having a nice reliable CIS system, which I now know is achievable, is my goal. And the motivation being the price of carbs, I wouldnt leave the CIS anytime soon.

Thanks for the help,
Ill keep the progress updated.
Scott

I would consider buying another CIS system just for parts alone. Having a good, not cracked airbox, good working valves and sensors, etc. would be good backup stuff. But chances are, I wont end up buying parts unless I need them.

Problem is CIS parts don't always take too kindly to sitting around. That is usually when the problems begin.

Thats good to know. Truthfully, I would have guessed the opposite to be honest.

Thanks for the help
Scott