I am trying to finish my 6 conversion, but have run into a few problems. I bought a wrecked 1983 911SC with the 3.0L engine with CIS. It ran great and everything worked in the 911. We carefully took the 911 apart and have been working for the last 2 months to put the engine and suspension in my 1974 914-4. I am trying to use the 911 engine completely stock including the CIS and CD box, etc. Yesterday we had everything back together and put oil and gas in it. We tried to run the engine, but are getting no fire. Most of the gauges, fuel pump, oil system, starter, etc. are working with no leaks. The oil pressure light works correctly and goes out as pressure builds, but we do seem to have a short in the oil pressure gauge. As soon as the ignition is turned on, the gauge pegs. We think that this is in the gauge itself and not connected to the firing problem. Are we wrong? Is there a connection? There is one major problem. We are getting only one small spark when we start to crank it. With the starter turning over the engine, there is no additional spark. We have checked our wiring and connections, but find nothing wrong. If we were to test run the engine on the bench, what would be the least number of wires to connect? We have tried to use a Haynes manual to follow all what we consider necessary circuits. As this is a track car, we did not connect up the a/c, heater fan, cruise control, power windows, etc.

Do any of you have ideas? Any help would be greatly appreciated as we are supposed to run it at the track next weekend.

Grady

Points. $7.00

Either some ignition component is dying or not enought coil saturation for a healthy spark.

Check your manual...see what gap is required, then check and see what you have.

Parts are so cheap, I'd replace everything in the ignitions system so that you know everything is fresh and healthy.

Then you can drive with confidence.

Good luck.

Roger

QUOTE (rogergrubb @ Oct 2 2005, 03:13 PM)

Points. $7.00 Check your manual...see what gap is required, then check and see what you have.

the manual will reveal that a 1983 911SC engine had a breakerless "Hall effect" distributor...

the oil gauge issue sounds to me as if someone mistook the gauge's "G" terminal for ground. (it's not - it means "gauge" and it's where the sensor lead goes.)

are you *sure* you have all 6 leads to the CDI box going to the right places?
could be dead CD box. the CD box must (IIRC) be grounded by the case.

but that's where i'd start - make sure you have a good signal from the dizzy, and make sure the CD box is triggering properly.

We just had the same problem on our 82 SC. We had the CD box rebuilt, and replaced the coil. The problem wound up being a bad coil, but because we had an intermittant short in the CD box ground, it wouldn't fire. New plugs & wires ($$), and it runs great. It took a while to trace it all down, but wound up being simple. IIRC, the Cap'n said the coils fail very rarely, so a dead one was a suprise.

Thanks all, we are trying the various suggestions. We grounded the cd box to chassis, but no luck. What is the procedure to check the coil without buying another one?

call Pat B. He put one in and had a sensor or two he had to kill and or fake out.

QUOTE

check the coil

pull a plug wire and hold it near the case while someone cranks it. Should have a bright spark that makes a snap sound every time it gets hit.

Wear a rubber glove, please. i still have plug wire shell shock...


KT

( my guess is the pulg wires are crossed or the timing is off )

This may be too obvious, but you are getting the high pitched whine of the CD box when your ignition switch is in the ON position, correct?

Good luck and I hope you find your problem soon.

Thanks all, major problem solved. CD box was not whining and therefore not powered up enough. Too much voltage drop in bad wire or relay. We bypassed them and it fires. Now if we can just find the short in the oil pressure gauge. It is wired right; we checked to make sure that g plug was not grounded.

Grady

QUOTE (shadygrady @ Oct 3 2005, 07:02 PM)

Now if we can just find the short in the oil pressure gauge. It is wired right; we checked to make sure that g plug was not grounded.

ok - are you sure it is connected to the pressure (gauge) transducer and not the idiot light switch?

QUOTE (rogergrubb @ Oct 2 2005, 11:13 AM)

Points. $7.00 Either some ignition component is dying or not enought coil saturation for a healthy spark. Check your manual...see what gap is required, then check and see what you have. Parts are so cheap, I'd replace everything in the ignitions system so that you know everything is fresh and healthy. Then you can drive with confidence. Good luck. Roger

Hard to find a place to put those points on an SC, since they don't have them. There is NOTHING cheap in an SC ignition system.

Check the power and grounds to the CD unit, check the voltage generated by the distributor (the green wire and the ground braid, right next to each other), check the coil wire, check the coil itself. They fail often. Just went through this on Mark Britell's GF's car. Bad news is the coils are currently NLA, but I have a new one available if you need it. DON'T EVEN THINK ABOUT RUNNING ANYTHING BUT THE CORRECT COIL!!!!!!! I also have a CD unit. The Cap'n

QUOTE (ArtechnikA @ Oct 2 2005, 03:19 PM)

QUOTE (rogergrubb @ Oct 2 2005, 03:13 PM) Points. $7.00 Check your manual...see what gap is required, then check and see what you have. the manual will reveal that a 1983 911SC engine had a breakerless "Hall effect" distributor... the oil gauge issue sounds to me as if someone mistook the gauge's "G" terminal for ground. (it's not - it means "gauge" and it's where the sensor lead goes.) are you *sure* you have all 6 leads to the CDI box going to the right places? could be dead CD box. the CD box must (IIRC) be grounded by the case. but that's where i'd start - make sure you have a good signal from the dizzy, and make sure the CD box is triggering properly.

The CD box doesn't need to be grounded by the case, but it's a good idea. In lieu of the typical Hall Effect unit we are used to seeing, the SC has a reluctor, and generates a current pulse. The coil portion and the wiring unit are available as spare parts. The Cap'n

A new problem. The engine is firing but won't run. We pulled the plugs and they are now fouled, so we will replace them this evening and maybe this will solve our problem. The Haynes manual and the Bentley 911SC service manuals both say that the direction of the distributer is clockwise. But my rotor is turning counterclockwise. Which is correct? Have I somehow reversed the wiring where I can't see it? Thanks again

Grady

Meanwhile my wife just laughs.

Could the rotor direction problem be that you took a tail dragger engine turned it around and put it in a mid-engine car and now you are looking at it backwards?

M

finally, it runs and starts great. Rich J, the muffler sounds great. the problem was a crossed wire to the tach. that purple wire. crossed on back of gauge under dash. all this time. oh well. duh!

Excellent! Great job!