83 911 SC died won't restart

[911 Camper]

I have an update from last nights testing. I have ruled out the green wire, it looks good and continuity checks out fine on each side but not across. I checked the gound strap at the transmission and that appears fine. I jumpered the fuel pump relay, it hums great. I pulled the distributor to get at the green wire and cleaned the pickup coil connections. Charged the battery back up and the tach doesn't rise anymore on cranking, that appears to have been an the issue, unrelated. I checked battery ground and tested continuity in the entire front and rear fuse panels, all good. I pulled off an injuctor line on each sides of the engine(1 and 4) and I have fuel. Pulled the plugs, nothing irregular, a little wet from the cranking but normal. Please help with more ideas!!!

[elpresidente]

I know this sounds rediculous, but how's the fuel level? Sometimes with good reason, I don't trust the guage. Ask me how I know? Not trying to insult anyone's intelligence here, but it sounds like everything else checks out.

I have also simply removed the airbox cover and lifted the pop-off valve, then replace cover. For some reason that seems to have worked too.

[911 Camper]

No insult taken Mr President, I did think of that after reading another thread to that effect. and I have checked the pop-off valve and made sure it was seated. Thanks for the input.

Does anyone have a thought on this: Systems consulting seems to think the coil is bad. It is a silver Bosch coil. Any thoughts?

[Superman]

Wet plugs suggests absence of ignition.

Ignition is finicky. It is also......usually.......the cause of no-start problems. The most common cause. I would check the spark again. It needs to be blue, not yellow. And it is audible. SNAP. If you are getting fuel, and you are getting a snappy blue spark, then I would wonder about spark timing or something similarly wacky. Distributor jumped a gear tooth, or something like that. Static timing could be checked, to make sure the spark is happening around TDC. Except that.....with electronic ignition I'm not so sure the static timing test would work. No points to open.

Get out a timing light. Hook it to the #1 wire. See if the timing light flashes, and if it flashes at around TDC for #1.

Again, if you've got compression, and the proper fuel volume and air, and a hot spark happening at the right time.......then your engine would be running.

[Superman]

You can eliminate the coil suspicion if you verify a hot spark.

The popoff valve would not affect starting for the first few seconds. There is a cold start valve in the back of the air box that sprays during starting. It would cause the motor to vroom to life, but then if the popoff were a big hole, it would die as soon as the CSV stops spraying.

Remove the air filter and, while someone is trying to start the car, lift the sensor plate a bit. If this starts the engine, then perhaps your CSV is not operating.

[911 Camper]

Thanks superman and All,

I tried lifting the sesor plate during cranking and nothing. I am starting to point to a weak spark. When I tried it I had to basically ground the coil wire to get it to arch and it was not audible over the engine cranking.

Last night my wife expressed that she was baffled that I would drive a car that I need to tinker with; I am as frusterated as I have been in a long time but in some weird, warped, German way I think I actutually enjoy it. If I didn't I'd drive a newer VW.

[Walt Fricke]

Mike

It helps to have a nearby support group. Someone who will drive over and swap his coil into your car, and yours into his. If his car then works and yours doesn't, your coil is probably OK. Then you do it with the CD box to see if that is OK.

I agree with Superman - even with massive air intake leaks, as with a broken box, or a popped popoff, or a dislodged (or cracked) rubber boot, you ought to get at least some sign of life out of the engine when it is cold, via the cold start injector.

If you have air, and gas (enough pressure to make the injector inject, not just enough that something comes out a like with no injector on its end), you've pretty much got to have a spark problem.

One assumes that when you pull the distributor cap, all the innards look good, and when the engine turns over the distributor innards also rotate as they should.

Re: wet plugs. Have you pulled all of them and dried them out? While they are out you might disable the fuel pump (pull the relay) and spin the engine some. I don't hold out much hope for this, but who knows at this point.

You'll figure it out (eventually).

Walt

[911 Camper]

Walt, Superman and all the other great posters,

Tonight is coil night, ground cleaning and connector cleaning night and hopfully it will wake the beast.

Walt, one question, is spinning the engine to dry it out or just see if I feel anything abnormal?

Superman, in MT a support system is hard to come by, I have become faily self supporting. The one key piece to this puzzle I am missing is a spare CD box.

[AngM018]

If you have been cranking quite a bit, once you do get it started make sure you change the oil. too much fuel getting into the oil could dilute it enough to cause wear issues.

I would pull the plugs and let the cylinders dry out over night. this will give you a good opportunity to verify TDC on cylinder number one and double check the dizzy rotor position and re-do your static timing. I couldnt get mine started after a rebuild and found out I had the dizzy out 180 degrees.

[mca]

Just want to throw this out there as a shot in the dark.

What is the voltage at the battery?

I had a terminal come off of my battery. During the process of "coming off" it fried my Voltage Regulator.

I had intermittent experiences when the car would just cut off but this was always preceded by electrical issues (tach bouncing). The VR was fried but still working until it finally crapped out.

My battery was also blown in the process.

New battery and new VR fixed it ... been nearly a year now and not a single issueu since.

Just a thought! Would not hurt to have battery checked out.

[Walt Fricke]

Mike

I figured spinning a spark plugless engine would help dry it out. John's idea of just letting it sit overnight that way may be a better mousetrap.

As to alternators/batteries, if you still have 11 or so volts while cranking (with plugs in), I don't think any of that matters (excpet perhaps to the tach). That should be enough to get an adequate spark to the plugs.

And do test the spark at the plugs, not at the coil, if you haven't already. The coil was a good place to start, but you want to know you are getting spark through the distributor. Sometimes things go wrong in there, even though it seems a simple system with little that can go wrong. This is along the troubleshooting philosophy of checking for fuel coming out of the injectors, not just getting to them.

I would rate the chances of your distributor's timing being so far off as to have caused this problem as slight. This was an engine that ran fine, and suddenly quit and won't restart. If something snapped in the distributor system you should see uneven movement (or none at all) when cranking with the cap off. Though it never hurts to check.

Walt

[911 Camper]

First I want to thanks all of the Pelicans who help me with my dead SC. THANKS

So many threads end with out an update on progress or a solution explained so I vowed toalways post solutions when I figure them out.

1. The jumpy tach was caused by low voltage from cranking to much, a good charge solved that.
2. The weak spark is what caused the car start.
3. When I pulled the center coil wire from the top of the Distributor and held next to a grounf while cranking the engine it would only arch abut 4 mm. After reading more threads it should arch 15 to 25 mm. My deduction was that it was either a bad coil or a bad engine ground.
4. I found a not loose but not tight gound from the panel board that tha CD box and relays are mounted on. It grounds behind the fuel filter and accumulator, I cleaned and tightened. Now instead of a ohm test of .5 to .7 ohms between the engine and panel I now get .3 to .4. I also installed an additional gound strap from the engine to the panel and with that addition I an now at .1 or .00 ohms.
5. I also replaced the coil, mine tested fine on primary and secondary but the spark still wasn't up to par.
6. After all of this work it fired right up.

QUESTION: Could the weak gound have fried the coil?

Thanks again; now I have to takle a non-advancing distributor. I may need help but will start a new thread.

[Superman]

I'm told that a bad ground can kill a CD box. Get a spare. Poke around on the Parts For Sale forum. $50 is a great price. $100 is more typical. New ones are something like $1500!

At any rate, you showed some wisdom by chasing down those ground resistance problems and especially installing another new ground conductor. Bad grounds are common, and troublesome. Ignition systems are terribly persnickity. I consider caps and rotors to be worn out by 12K miles.

You did well.

[Gunter]

QUESTION: Could the weak gound have fried the coil?

Thanks again; now I have to takle a non-advancing distributor. I may need help but will start a new thread.[/QUOTE]

Sometimes just poking around can bring temp success but..................
You may still have an intermittent problem with the ignition.

Service your distributor the easy way:

http://forums.pelicanparts.com/showthread.php?threadid=333640

If you need a working vacuum can for an SC with advance and retard, I have one for sale.

[911 Camper]

Thanks Guys,

I printed your thread and will perform it tonight. When I had the ditributor apart I removed the screw under the felt and the shaft cam out also? Did I hurt any thing? The timing seems to be retarding fine but not advancing.

I was going to check my advance with a vacuum pump. How many pounds should advance and retard?

[Gunter]

Outch!
I mention in my thread to ignore the center screw under the felt.
The screw holds the top part of the shaft which moves in conjunction with the weights (Mechanical advance) and doesn't need to come apart.
Dismantle the distributor per my thread and check the top part of the shaft to ensure that it is installed correctly; it should rotate a small amount and move the weights on the bottom.
Clean and lube making sure that the vacuum advance plate moves freely!
Re-assemble everything but leave the cap off.
Check your vacuum the old-fashion way: put a short tube on the advance nipple and suck on it; it should move the plate a little.
Once installed, the ignition timing ranges to about 33 deg. (Make a white mark on the pulley at 32-33 deg)
Use a timing light, start with 5 deg BTDC, rev and watch the mark. It should max out to 32-33 deg after 4k RPM.

[2002M3Drew]

Check the plugs right under the dashboard right by your left leg...there are three or four of them, all round. They look like plugs that go into a foreign wall socket. They come loose sometimes. One is for the ignition (literally, the plug wire leads back to the iginiton switch/key), and if that plug jars loose but doesn't completely come out, the key may still get everything going (i.e. the fuel pump, the box in back, the idiot lights, etc), but it won't turn over. They come loose quite a bit!

Mine came loose at an autox last summer, and it was the last thing I checked (I checked everything you did in the pits), but boy what a relief when I felt that plug loose. Funny thing...two months later at a DE, a friend with a similar SC had the same problem, I reach in under his dash...same thing! Try it.

Based on your "car just died like someone switched off the ignition," I wouldn't be surprised... Good Luck!

[myfast911]

change your cd box.this happened to me a while back.i had spark whe i tested for it,but it turned out to be not enough.my tach alos went buggy.i put in a msd 6al and was back on the road that same day.good luckto you.

[911 Camper]

http://http://forums.pelicanparts.com/showthread.php?t=388019

I posted a new thread on the distributor issues, hope someone can help.