george44

Hi there, some trouble, don't knowe how serious. Car is a 911 SC '79 Euro (engine code 930/03). Replaced all plugs on Sat with Bosch silver tipped (WR 7 DS). Car starts instantly from cold (as usual) and then again as usual can't seem to hold steady while warming up, RPM goes up and down all the time (between close to 0 and approx. 1,800). Hold the foot on the gas pedal to stabilize it under 1,000, all is well as long as I keep my foot there, if I take it off the engine will die. Again, it's been doing this for a long time (years) but eventually it warms up, idle steadies and it runs beautifully. This time takes a bit longer and actually have to re-start it a few times while stopping at intersections, the idle won't hold. Eventually it stabilizes. After approx. 20 minutes I pull off from the highway remembering that oil is probably under the Min mark (it was very hot and very humid near Toronto this past Sat and I thought there should be at least enough oil to avoid surprises). Top it off, try to re-start, car won't start for anything in the world. I did experience this problem in the past, sometimes (not always!), it is very hard to start when hot and after sitting for a few minutes (5 min or more). What I do in such cases is crank while at the same time keeping the gas pedal floored and it will eventually start. Not this time, it's dead solid, engine turns, no abnormal noises or anything suspect but it will not even try to start (well, in many attempts, it tried once but did not go). My battery goes away (it was very weak anyway), jump start from another car, and then another after one hour or so, and then another, nothing, engine turns, but will not even attempt to start. I remove the spark plugs to ventilate the cylinders, open the pop off valve, try to start without the air filter, nada. Eventually bring the tow truck (big shame, had to swallow my pride) and take it home. Was sure it will start when cold but unfortunatelly it did not, same, it turns fine but no attempts to start. There is spark (I've turned it by hand with a wrench and took one ignition wire from each side and put a spare plug in it and grounded it) and judging by the smell there is gas (and I've also seen gas on the plugs when I removed them). The gas pump is working, I can hear it, the CD box has the high pitch noise, all seems OK. I'm not 100% sure but I believe the engine has been updated to the automatic chain tensioners, the previous owner had a catastrophic failure (back-fire) and all the engine had to be rebuilt. I'm at a loss and don't know where to start, I have the Bently, looked in it, unfortunatelly either I did not find the correct information or it's not there, what it says under 152 and 200 did not help much. Any advice on where to start and what to do? I've actually had a very similar problem several week ago, I started it in the garage, then wanted to take it out for a ride, did not accelerate hard enough to get out on that downward sloping driveway of mine, engine died, impossible to re-start (this after the engine has been running for a few minutes). I put it back in the garage (the slope obviously helped this time), tried again a few hours later, it won't start. Then I left for vacation, when I came back two weeks later the car started right away but was smoking (black smoke) and the engine did not seem to run properly (like now it fires on all cylinders and next minute it doesn't). Took it out for a spin, pulled OK, nothing noticeably wrong. But this is what made me decide to replace the plugs (I wanted to replace them anyway).

If all fails I would need to tow it to a shop. Is there any way to pull it from the rear, the car is now in the garage with the front facing the wall and the driveway is downward sloping, I would have to somehow hook a cable at the rear to pull it to the street so that the tow truck can load it. Thank you very much to all for help and sorry for the long post but I've tried to describe the symptoms as best I could,

George

Brett San Diego

How are your fuel pressures (hot and cold control pressure and the system pressure)? How is your mixture adjustment (%carbon monoxide (%CO))?

This is where you should start with diagnosing the CIS system. Plenty of reading all over the web.

What about the age of your distributor cap and rotor and spark plug wires?

Brett

sww914

I think that the erratic rpm at idle was as a result of a too rich mixture. Later, when it was puking out black smoke, a sure sign of too much fuel. I'd start with fuel pressures as Brett suggested, and when if you get it started again, adjust the mixture. I don't know if a '79 euro had an oxygen sensor, but if it does, measure the voltage it's producing when it's warmed up. The too rich for a long time might have killed it, especially if it was old anyway.

george44

Thank you guys, no, I have not checked the fuel pressure and I don't have the tools to do that in my garage but as you say Brett I know there is info available so I'l dig into that and should be able to buy or borrow what I need from the local Canadian Tire (the Canadian equivalent to Pep Boys, Auto zone in the US). NO idea on the age of the distributor cap, rotor and ignition wires, bought the car in 2000, I have not changed them but I do not drive a lot either, climate here is a bit cold and there is salt on the road in winter time. And it does not have an O2 sensor or an air pump. Thank you,

George

theiceman

George

I think you should have a rubber plug in the rear bumper , this pops out and you should be able to screw in the eyelet from you toll kit. This would allow you to pull it out of the garage. Cold fuel pressures etc are always a good start but I am not sure if you can get the type of pressure tester you are looking for at crappy tire. Sounds like a trip to Mantis to me. Replacing the cap and rotors are simple starts but the problem definitely sounds like fuel delivery. What about a clogged fuel filter ? These are all PM things anyway and changing these are certainly not going to hurt and should be done anyway. There is always the fuel pump and the fuel pump relay. I know the pump is running but is it developing enough pressure. There is always the warm up regulator , mine was stuck when I took it out of storage this year and the car would not idle under 1700 rpm. Eventually it settled down though. Depending on your level of expertise a trip to the shop may prove cheaper than shotgunning parts.
I have a 78sc and if there is anything I can do to help pm me . I am in Cambridge and visit Burlington qite often. In fact I was just at Spencer Smith Park yesterday .. too bad, I could have swung by and had a peak..

PS let us know if you get the presure tester.

theiceman

one thing I just noticed ... probably just my interpretation but thought I would ask. You said you topped off your oil and it wouldn't restart. You do know you are suppose to be checking your oil with the engine running and warmed up and at idle right ? If you are topping up then restarting could you be competely oil fouling your plugs ?

theiceman

Not sure if you have seen this but it may be helpful.

http://www.pelicanparts.com/techarti...warmup_reg.htm

Brett San Diego

A CIS fuel pressure gauge is around US$100 (maybe cheaper if you look around). If you intend to DIY on this job, it's worth it. It's a small price to pay vs. taking it to a shop, and you'll have it for next time. Definitely put in a new fuel filter and distributor cap and rotor, and I'd recommend new spark plug wires, since you apparently don't know the age of any of these routine maintenance items. Now is a good time for a routine maintenance.

Brett

theiceman

George I have some parts for testing if you like. When i got my car it was running fantastic so I kept the parts I took off. I also have a spare rotor ( sorry no cap ) and a set of wires. I don't think it is the cause but it is nice to help eliminate things.

george44

Hi, wanted to respond from work but could not log on (did not have the password with me). Found the rubber plug in the rear bumper and found the eyelet, boy, this car is all original, the eyelet even has the little carton sticker with a sketch on how to install it. So this is solved, I was actually thinking as an alternative to lift it on the hoist and then slide a two wheel dolly under the rear wheels and move it like this. Now to the plugs, you are correct, I did shut down the engine, poured almost two liters of oil (two quarts) and then it won't start. What you say (fouled plugs), on one hand I would be in the 7th sky as this means there is nothing really serious with the engine, on the other hand if this is indeed the case I will never be able to forgive myself for doing such an idiotic thing (for lack of better words). I will go right now in the garage and replace all plugs with the old ones and see what happens. I know and have thought at these myself, cap, rotor, wires, but the engine does not make any attempt to start, it just turns. Died like this on a clear, hot and humid day. Would be more inclined to the gas filter. And wish I knew you're in Spencer Smith Park while I was running around scratching my head what the heck to do and where is all coming from. Oh well, will keep you all posted and many thanks for taking the time to help me with this!

George

theiceman

..er you may want to drain som oil out first ... and take the air filter out and inspect your intake and look for oil . If you have overfiled your engine oil would have gone in. I am surprised you didn't see oil billowing out .. but then again it never started. You should be mid way between the min and max with the engine running ... you may have to suck it out the tank with a suction gun . lots of funny stories of guys trying to let a little out of the tank... myself included.. either way don't sweat it .. lots of help around. If you PM me your address I can drop by some time in my car and have a look with you . I know Burlington pretty well as I lived there for 20 years.

george44

Ahem, put the old plugs in, car started after a little hesitation and not firing on all cylinders; some whiteish smoke for a couple of minutes, never seen something like this,if it were water cooled I would have said the head gasket gave way; then some black smoke for a few more minutes but less and less; now runs fine, no smoke and fires on all cylinders, have not taken it out from the garage but you can say when it's running on all 6. Same problems, rough idle and stalls if I don't keep my foot on the gas pedal (or my hand on the linkage in the engine compartment). Thank you very much, guess I won't forget this that easily.

George

theiceman

George now that it is working ( sort of ) it might be a good time to get it checked out before it leaves you with a tow bill. Mantis is good and I think there is a tech centre in Burlington somewhere run by Marc Plouffe.

george44

Yep, you're 110% correct, I need to do something about it and I've been procastrinating for a couple of years now (how typically Canadian is that, eh?), you see when it runs fine when warm and only occasionally gives you a bit of trouble by making difficult to start when hot there is not much incentive to spend the $$$$ to fix this little annoyance. But this has been a major annoyance so I'm going to take it to a shop. I spoke with Marc a few years back and he sent me to Auguste in ST. Catharines, had the car there once, all went very well, the problem is that I would have to leave the car, come back to Burlington, then go back to take it. Mantis is much closer and more convenient, can easily take the Go train or even a cab, it's not that expensive from there to Burlington. I'll have to decide where I go but I know I have to.

George

theiceman

If you go over to Mantis I can run you back .. Just let me know when .. Ps I PMed you

Ice