Have you checked fuel pressure at start and ever replace the fuel filter? I had that problem with my 83 SC.

I haven’t gotten the chance to get back to continued trouble shooting yet. Hope to have some time to spend with it tomorrow. Will report back my findings

You don't even have to wiggle if you use the screw driver method I talked about. Just be gentle. Try it on your test connector. It takes a millisecond ... anyway ... like you said back to the OP's original question.

I actually removed them all in situ prying out the spring clip and as Bob said I'm glad the large caliber weapon was not available. I learned the hard way when it comes to these plugs.

Plug removal.......
 

Gary,

Since you could remove this plug in milliseconds, I will give you an opportunity to demonstrate your technique. Try to remove the plugs for the AFS, FV, and CSV with the engine installed using your special tool. And I will give you 10 mins. to remove them. You could not even see these plugs with the engine in place. How could you even pry these tiny springs off?

These plugs were built and designed as push/pull plugs as a quick disconnect connectors. Keep us entertain. Thanks.

Tony

Was able to do some testing of my thermotime switch tonight hopefully my explanation below is clear enough. I removed the switch from the car and tested on a bench.

Large terminal on switch = red black wire on car (this grounds the CSV)
Small terminal on switch = yellow wire on car (power at cranking)

I grounded body of switch and connected my test light between large terminal of switch and + and my Test light comes on.

With the above still connected if I apply power to the small terminal of switch my test light goes out immediately.

So this seems to indicate the switch is bad. Shouldn’t my test light stay lit for approximately 3-5 seconds when I apply power to the small terminal? If I’m understanding this circuit correctly with the CSV then when my car is cranking at startup my CSV would not have a ground and thus not be giving my car the extra shot of fuel at cold start right?

who's the boss? tony is.

OK to settle this ... just tested both techniques on the spare.

Gazzerr,
The screwdriver method works like a charm, quick and yes millisecond indeed, a simple twist and the connector literally pops off. Tony's wiggling works too but takes a second or two. In addition, I like that the lever force is applied on the strongest side of the connector (see second pic) so yes, this lessens the possibility of these 30yr plastic pieces snapping off with all the wiggling, a little impatience and brute force.

Not in situ, of course.

Fun stuff, this forum is amazing, where no dog is too old to learn new tricks, right BK ? :)

http://forums.pelicanparts.com/uploa...1544412680.jpg
http://forums.pelicanparts.com/uploa...1544412689.jpg

Test results.........
 

Brian,

I read your test result earlier but was not in a good mood to reply due to the Eagles’ defeat in overtime. Anyway, I got your PM too. Your test shows that the TTS is switching off too early. My previous tests showed less than 5 sec. for the six (6) TTS tested before they switch off.

If your TTS is switching off immediately after you energized it, it is defective and time to replace it. But this is only half of the test you need to do. With a good TTS, you need to physically observe the fuel delivery of the CSV too. Make sure it is not leaking and delivering strong mist-like spray pattern. However, both TTS and CSV are very robust CIS components but fail too.

You are doing a good job troubleshooting your problem.

Tony

Troublemaker...........
 

Juan,

You are a provocateur and a troublemaker. You are not helping anyone by your immature posts. Instead of contributing in this Technical Forum to help and assist other people, you seem to enjoy making people get into conflict. What satisfaction do you get from your posts?

Tony

More testing this morning.

Ambient air 55 degrees

25 ohms - WUR resistance (used by he wiggle and pull method to get connector off)
1 bar - cold pressure
1 bar - 1 min
1.25 bar - 1:30 min
1.5 bar - 2 min
2 bar - 2:30 min
2.75 bar - 3 min
3.25 bar - 3:30
3.5 bar - 4 min

So colder temps are taking longer to build pressure. Still seems to be about .5 bar low at cold start but warming steadily to a within spec warm pressure.

Also retested my thermotime switch on bench a few more times and seem to be getting proper function. So except fo having numbers I’m right back where I started.

Looking more like I’m going to have to do a drop in order to test my CSV.

Anything else I can / should test before having to go that route?

Have you checked timing and ignition components and verified you're getting a strong spark? This would be an easy thing to check before accessing the csv.

the same satisfaction you get possibly by berating anyone who posts something you feel is not a technique of accomplishing something the way you see fit. nobody here doubts your extensive knowledge base. but on two occasions in this thread you belittled people, both pmax and gary with your replies as to how they are wrong IYO.

back to your regularly scheduled programming.

+1

Hope we get Wyatt straightened out.

WyattEarp,

Just want to confirm something to make sure we’re on the same page. You’re describing hard/no starting when the engine is cold, right? I’m just asking because I’m wondering why you’re repeating the fuel pressures test. No harm, and it shows consistency. Just trying to understand the logic. Understand the fuel pressures might not be perfect but the cold control pressure can be near zero (really, really rich) and the car will still start.

Your condition is crank, no fire. So likely culprits would be fuel starved, air starved or weak ignition. I’ve never tried it myself on a 911 but what about a little starting fluid? If it fires up that’s pointing back to fuel starved.

Fuel related: If TTS is ok, then you have to check CSV. Check the plug to make sure it’s connected. Can you verify it’s getting 12v when cranking? That would rule out wiring problem to CSV.

Spark related: I’d pull the coil wire and check for spark quality.

Air related: Once you get the car running you say it runs fine. If you remove the oil filler cap does idle change? It should. If not you have a decent vac leak somewhere. Maybe not the root cause but probably not helping. AAV provides a little extra burp of air on start. AAR is designed to be open on cold start and closed when warm. If it was stuck closed on a cold start that would be a problem. Only way I could see that happening is if it seized.

I’m just trying to frame up how I would be starting to formulate a plan of attack to the problem.

My next stop would be the CSV.

CSV Pressure test.........
 

Brian,

Performing a CSV pressure test with the engine installed for ‘81~’83 SC’s is not as easy compared to ‘80 SC’s and earlier models because of the metal fuel lines. Those CIS engines particularly ‘80 and earlier models have flexible plastic fuel lines and easy to move the CSV with the fuel line connected. You can not do this with the metal fuel lines.

So to be able to do a visual CSV flow test for your late SC with metal fuel lines, you need a special fuel hose to be able to test it. Unless you have a CIS bench tester. Removing the CSV with the engine installed is not that convenient because of its location but you can remove the CSV without removing the engine. A partial drop will help access the CSV. Once you are able to get the CSV off from its mounting by removing the two (2) Allen bolts, connect the CSV with an extension fuel line back.

I will post a picture of the extension fuel line I built to do the test or you could improvise. The key is to be able to put the CSV in a container to collect and observe the fuel delivery of the CSV.

Do a mock up operation for removing the CSV and visualize the things you need to get the job done. For example, do you need additional space for access? What tools do you need? Is it doable at the current set up? How was this done by others? These are some of the things you should be aware off.

You have not done this before and could intimidate you. It is not difficult by very tedious and cumbersome to get the CSV off and test it. Don’t get frustrated or discouraged at the very beginning. It is doable and you will succeed if you think you could do it. I have more tips to share with you.

Tony

I was able to pull my 81 CSV out far enough to see the spray tip with the line on.

I am almost certain I did this without a partial drop. However, I should not have as just a few inches makes a world of difference.

I place rags all around and killed the ignition.

Rigged a tripod and video camera up to capture the spray event. It was working fine.

That said, this was in my younger days when I cared not for forearm scratches and bruises. I should have confirmed that each connection point carried voltage at the right time or interfaced with ground properly before testing a very robust, yet hard to access component. (Me thinks Harry stated this many posts ago)

Side not: Just tested ohms on my 81 (090). 27 ohms. 60F on the WUR body (laser thermo) with heat on in shop. Earlier this year tested at something like 45F and it was 10 ohms. There may be something to that stepped ohms business talked about in separate threads.

Sorry about the Eagles. Cripes, the Cowboys. You should be at least a little happy the Browns won.:D

Cold start valve removal.........
 

Brian,

This is how the CSV looks like installed on the motor. With your engine installed access is quite a challenge specially if you have big forearms.

http://forums.pelicanparts.com/uploa...1544583612.jpg

To get better access reaching the CSV you could do one of the following:
a). Remove the CIS boot “Pope”.
b). Do a partial drop. Or
c). Drop the motor. I don’t recommend this at this point.

Use a 4-mm Allen wrench to remove the 2 Allen bolts securing the CSV. The hollow banjo bolt for the fuel line requires a 12-mm socket or box wrench. Loosen the fuel line first before loosening the CSV and place some absorbent materials or rags to collect the gasoline that might drip during the process. Make sure you don’t lose the o-ring for the CSV.

Since you don’t have a fuel line extension you could improvise for the CSV flow test. I will update this post with the CSV installed backward for your test. For the meantime, I like to know if you could follow the procedure. We will go to the detail later.

Tony

I see where you are going with this. Outstanding.

Surely I stressed the metal lines to pull it out far enough to see. I would not have had to do this (with backwards procedure) but it was before Pelican that I ran this test.

So I think I may have found my problem. Still need to get a larger sample size (more cold starts) to be sure.

Weak battery may be the issue. Apparently the car is very picky about having a very strong battery at cold start (is this a CDI thing??). The car sounds like it is cranking just as fast but fails to start. Looking back now the fail to starts have been after the car was sitting for a week or more.

I have two cold mornings in a row now with reasonably quick cold starts (say two 5 second cranks). First morning I had the car on a charger overnight after having done pressure tests. Day two was after driving the car the day before so nice full charged battery. Car actually seems and smells a bit rich when cold but given the cold pressures I am getting that is probably correct. As sooon as the car warms up a little it runs perfectly.

So this may have been a CIS thread in error. Good news is I have learned a bunch about my car and CIS thank to everyone that took the time to respond to this thread.

Functioning CIS engines fire instantaneously.

The strong battery masks some of the symptoms.

Not sure if you are shutting down for the winter but, if so, pull your WUR and send it to Tony for a tune up.

Walk away for a few days if needed but I still feel the cold start system needs attention.

Winter around here is the best driving weather. WUR tune up might be something for the middle of the hot humid summer. I will continue to try and get this sorted a bit more as I would like to have a car that starts instantaneously in all conditions. Testing the CSV is still on my list of things to do but I may save it for a 'while I'm there" task.

Cool beans. Yes, it's definitely in there.

We all learned a thing or two. Merry Christmas.

Tony no that was my point. I DID remove them all insitu removing/prying the spring clip and it was a NIGHTMARE. And I ended up breaking a couple of the plugs. It took me probably 2 hours to remove all those damn plugs contorting myself back behind a loose airbox still sitting on top of the engine only attached by the harness. I was able to roll it around to get to the plugs but it was very difficult.

I discovered later on that all you have to do is use a TINY little bit of leverage with a screw driver on the base of the plug and it pops right off quickly and safely. I'm still kicking myself. Learning the hard way is a virtue. Like you said they are only springs. They don't need to be removed at all.

I always laughed at the service manual advice for testing the CSV. How do you pull it from the back of the engine and then test it in that space with the hard lines? I think the best advice I saw was to pull the pope's hat and watch it spray from looking down the throttle body (I think this was a Tony tip). Pull the plug on the coil first or you might lose your eyebrows. :).

I took no offence from your post. I think you misread what I was saying. I think opinions should be challenged. That's what makes this forum valuable.

G.

Pretty sure the later SC's have runners inside the airbox to lessen the airbox explosion. The runners block the view. Maybe 1980 they started?

So doing more investigation today and I found that my pop off valve was loose. Epoxy was no longer holding. So I took it out, cleaned everything up and re-epoxied it.

Don't know if this is all of my problem but could certainly be a contributor I guess.

Oh yeah that will cause a massive air leak that can lead to a backfire and blow up your air box anyway.

I can also be a small leak from fatigued (cracked) epoxy. Flopping in the breeze is one thing, a fissure/tear is another.

My bet is the as OP nails these various cooties with reading and hands on work, his car will transition to warm much more smoothly and he will be amazed at the difference in the car's operation.

I still say send the WUR to Tony for a tune up. Remove that variable.

And, of course, the probably CSV issue. Two starts at five seconds duration is too long.

This is what I am hoping for.

Persevere. There are only so many variables.

You're not selling? You have years to nail it.

I describe my SC ownership experience as BT and AT. Before and after Tony with respect to CIS. Advanced search will deliver lots of goodies.

Nope. Not selling. ... Driving

Yes, added in the 80.

I haven't had the pleasure of observing the CSV operating in situ closeup with the hat off but even with the runners, can't you smell the gas or hear it working ? Ignition disabled of course !!!

Revised and improved CIS airboxes.........
 

Originally, the ‘76~’79(?) CIS air boxes came without the “spider plumbing” found in the late SC’s (‘81~’83). Subsequently, the new replacement CIS airboxes both 34-mm and 38-mm ID now have the “spider plumbing” installed already. Not exactly sure when it was first introduced because I have a couple ‘79 CIS airboxes with the spider on them.

My ‘78 SC still has the old original airbox without the spider plumbing. And will replace it next time I have the motor out. So when you decide to replace your old air boxes, make sure you get the one with the “spider plumbing”.

However, you cannot perform a CSV flow test to airboxes with “spider” in situ. The CSV has to be removed from its mounting for visual test.

Tony

All factory replacement air boxes since '81 contained the spider plumbing. So if you encounter an earlier 911 with the plumbing, it just means the airbox had been replaced.

Cheers,

Joe

Got the pop off valve re-epoxied go to start the car this morning and no start. Crank crank ... nothing. Since the top of the air box was off I decided to just do the check with air sensor plate to see if fuel pump was running. Turn the key to the on position and lift the air sensor plate a bit and can just hear a bit of a click click towards the front of the car. Hmmmm. Pump was running fine when I did my pressure tests and car has been running since. So I pull the pump relay and hook up my jumper wire/switch like I was going to do tests. Turn ignition to on and pump runs fine (just ran it 1 sec at most). Hmmmmmm. Put the relay back in. Try to start car and it fires up almost immediately first crank. Little short drive turn it off and as usual car starts right up after its been running. Take the air box cover off again just to make sure I'm not crazy, turn ignition to on and lift the air sensor plate and yep pump immediately runs. So..... flakey fuel pump relay??

Try gently spreading the male prongs on the relay with a small screwdriver. Sometimes they get smaller as the relay is wiggled in/out for the jumper. Its also possible the male connectors on your jumper are slightly larger than the relay which may enlargen the female side of the plug. Of course, the relay itself could be going bad but some things to try before buying.

Good to keep a spare relay in the glove box. Yeah, keep a jumper wire and thin blade too for above purpose.

Try start it again on a cold engine without doing the jumper test prior.

The leaky toilet seat valve can cause your original problem.

http://forums.pelicanparts.com/porsche-911-technical-forum/976754-pop-off-not-pop-off-4.html