1980 RoW 911SC cranks but will not start

[erio]

problem solved looking for 901-602-502-00 coil
Hello
Im out of ideas and need your help. (go to problem begins if you dont want to read full story)
I have a nice 911SC, that i purchased in winter,
It drives very good, and starts right up.
After purchase i cleaned the aux air valve becouse of reving problem on cold engine.
It hepled and the temperatures are much better now.

I had a very bad battery, but the car always started after 1 or 2 revs, so it didnt bother me.
2 times i needed the push after i stalled cold car, and it didn't restart till batery died, i assumed overfloded
after the push it started right up.

Then a week ago I went to electritian to fix long short beam switch, fixed the lamp connector, and changed some short beam cable that was fried under the dash.
The car needed some turning - but started, and then i got home.
Next day I wanted to drive the car, but it didnt start and battery died.
I had this for a couple of times before but after connecting charging for the night next day the car started right up. Its a inteligent impuls charger. I didnt disconnect battery while charging the car.
I got tired of it so i got battery form my other car

THE PROBLEM BEGINS

I changed battery for a new one,
It turns like crazy, The tacho shows 4000rpm while cranking
the car doesnt even try to start.
I belive I even burned a little insulation on red positive cable going to battery cranking it too long

I hear buzzing after iignition on, on left from ignition module

fuel pump runs (tried disconnecting fuse 16 to disconnect pump)
There is spark, on a spare sparkplug connected to the wire and put on the engineblock

spraying quickstart does not make any change

the k jet plate is hard when i connect fuse 16, to prevent it from fuel floding again)

i cleaned the spark distributor and cap, didnt help

The idea of friend electritian is that i have no compression because the engine is cranking very fast, and after being floded with fuel it washed oil from between the piston rings. So i should crank with fuse 16 out, and than insert the fuse and it shoud start.

we already removed the sparks and heated them up with a torch, no improvement.

Im out of ideas

I have a guy coming today with tools to check fuel pressure and stroboscope light to check spark timing.

[boyt911sc]

Norm,

Hook up an inductive timing light and find out if you have ignition sparks during cranking. Determine that your 'sparks' are good and consistent. Check your fuel pressures (control, residual, and system). Lastly, check for unmetered air. I won't even bothered about compression at this point. Keep us posted.

Tony

[erio]

We didnt succeed in finding the timing of the spark because it was to weak.
When we connected the sparkplug directly to coil the spark was white and strong.
When we connected the spark to spark cable it was much weaker and redish.

The timinglight device worked on coil HIgh Voltage cable and blinked ,but conected after spark distributor the spark was too weak and the timinglight device didnt glow.

The ignition finger and cup look ok. The finger(rotating part) has 4.96 ohm resistance.

Any ideas
Is it possible the module went dead?
How hard and expensive is replacemwnt of bosch module.
Where do i go from here.

Replace all sparkplugs couse they can be damaged irreversably by flooded fuel ?

One more thing
Todey i got 5 single coths out of the engine for 10 cranking ,im making progress

Still when fuel punp was connected i could smell gass. I start ome time wigh and one tme without fuse 16

[erio]

today i took oout the fuses 1-8 from the lights
And the spark seams strong
and the car tries to start, but its seriously floded i suppose.

i will put new sparkplugs and it should start.

Something is messed up with lights after the last electric job, thats why some cables near battery are fried

[erio]

No progress

I changed the sparkplugs, and it didnt even try to start
I gave my ignition module (silver box on the left) to check by another 911sc user, and his car starts

Than I put some oil in the cylinder, than cranked the engine manualy, than cranked with starter to clean the cylinder, than put in dry sparkplugs, and than try to start,
NO SUCCESS

All theories of 4 mechanics died.

fuelpump runs, and when i lift the air flow sensor in Kjet, i hear injectors squiking,
Is it possible that the fuel filter is clogged ?


Give me some ideas,

The spark is bluish, and to me its strong

coil works, module works

HELP

where do i take the car,

-electrician?
-old guy that knows Kjet and will check fuel pressures ?
-180km to porsche guy

[Walt Fricke]

It sounds like you have spark (even if there may be problems there).

So how is the distributor doing? Is the rotor OK? Solidly seated and pointed in the right direction? Can you use your timing light, just cranking, to see if your spark is getting there at about the right time?

You sure it won't try to start when you spray ether (starting fluid) in? take off the filter to help with this. If you have CIS problems which are preventing enough fuel from being squirted in, ether should get it started a little. Sometimes, after repeating this, it will stay running, and then run and start when warm enough. Still indicates a fuel supply problem.

Buy a leakdown tester. <$100. That will tell you what the mechanical state of rings and valves is. Not likely these went bad overnight, but good to know that part is OK. 4,000 rpm on the starter doesn't sound right to me, either. Not with the spark plugs in place, anyway. You do need a compressed air supply for this.

Buy a CIS fuel pressure tester. Again, <$100. That will allow you to measure fuel pressure (should be about 5 bar/75psi) from the pump as reduced by the fuel distributor. And something called control pressure (should be down around 1 or 2 bar cold).

When I recently had a similar problem, finding that my control pressure equaled my system (~pump) pressure was a pretty good clue as to where to go next.

Jim Williams has a great website with information and specifications and troubleshooting stuff for CIS. Google Williams CIS and you should find it. And, of course, a search here will come up with lots of discussion.

[erio]

The
The ignition timing is too late about 2 cm.
On the picture you can see the 2 marks on engine are 2 cm to the right from mark on fan hausing.
How did they move
I will adjust it by rotating ignition thing with cap and finger

[Walt Fricke]

Sounds like a plan.

If getting the ignition in the ballpark doesn't work, you might pull out one injector and stick it in a bottle or something, and lift the plate and see if, in fact, it is squirting. Sounds like it is, but confirming fuel is getting to the combustion chamber is second only to confirming spark on the diagnostic tree.

[group911@aol.co]

Good plan. Fuel plus spark. Something should happen. Might want to pull all six injectors and stick them in bottles to be sure.

Originally Posted by Walt Fricke

Sounds like a plan.

If getting the ignition in the ballpark doesn't work, you might pull out one injector and stick it in a bottle or something, and lift the plate and see if, in fact, it is squirting. Sounds like it is, but confirming fuel is getting to the combustion chamber is second only to confirming spark on the diagnostic tree.

[Bob Kontak]

Regarding timing, reach down grab the distributor and see if you can rotate it without touching the locking nut. If it's not too tight you (anyone in there) could have bumped it and made it move a little.

Here is the very lazy man's way to check timing. Look at the locking stud and nut in these two pictures of different distributors. Notice the orientation is about the same between the two.

Does yours look like this approximately?

[erio]

Yes it looks exactly alike. The nut is firm and ok
Yesterday i tried pulling the car.
At 50km/h around 3000rpm on 2nd gear. Nothing not even a try to start.

[Bob Kontak]

You mentioned you had a real nice spark at the coil and a wimpy spark at the end of the spark plug wire. Then you said spark is ok. What did you do to make the spark improve at the end of the plug wire?

You mentioned the air sensor plate was hard. Have you tried lifting it a little with the key in the on (not start) position? It will scream like a witch that just had a bucket of water splashed on her. (this is a long shot since you tried starting fluid)

[Bob Kontak]

Here is an idea. Since you can take pictures, align your engine to top dead center. Remove the distributor cap, leave the rotor on, and take a top down picture from 18" away of the distributor. I would like to see where the rotor is pointing.

[erio]

The car was low on fuel. I added ofcourse and it has never been dry. I expect 5 literes minimum. I took the upper nut of fuel filter out and its spraying presure hard to hold with fingers. The pump seams ok. Today i will remove one injector and see it spray. Than i give up and take it on the lorry to mechanic

[erio]

To answer you ideas. Yes i tried cranking while manualy lifting the plate. Yes i could hear injectors and pump at that moment. I drive mercedes w123 280ce for 10 years.up to now I was yhinking of myself as a person that knows kjet
. When i connect timing light to this first cylinder wire i get flash when tdc is like on the foto above.
.

When the two scratches on belt wheel line up with the scrach on the fan housing so its T DC the rotor points right. I will make this foto. Points almost exactly to 1st wire going to 1st cylinder. The cylinder on the driver side(left) closest to rear bumper.
When i rotated distributor clockwise to the end. The timing light flashed near tdc and -5 marks. I tried starting the car bu pulling it . Didnt even try to start.
Im thinking its fuel.
Its like as if i refueld with diesel or water. All works but the car is dead
But its also dead spraying flamable starting fluid on throttle .

[pete3799]

Originally Posted by erio

To answer you ideas. Yes i tried cranking while manualy lifting the plate. Yes i could hear injectors and pump at that moment. I drive mercedes w123 280ce for 10 years.up to now I was yhinking of myself as a person that knows kjet
. When i connect timing light to this first cylinder wire i get flash when tdc is like on the foto above.
.

When the two scratches on belt wheel line up with the scrach on the fan housing so its T DC the rotor points right. I will make this foto. Points almost exactly to 1st wire going to 1st cylinder. The cylinder on the driver side(left) closest to rear bumper.
When i rotated distributor clockwise to the end. The timing light flashed near tdc and -5 marks. I tried starting the car bu pulling it . Didnt even try to start.
Im thinking its fuel.
Its like as if i refueld with diesel or water. All works but the car is dead
But its also dead spraying flamable starting fluid on throttle .

The distributor turns counter clockwise. Check that you have the plug wires in the proper order.

[erio]

I know it turns counterclockwise. Thank you for ideas. But Wires are ok. I turned distributor clockwise to advance ignition so it sparks pn 5 deg to tdc like on pelican tech article but it made no change

One more thing. I bet the failed part is going to be something related to electrician.
Something simple.
I promise to write at the end.
Car is going in 8 hours to classicporsche.pl 130 km from my place.

[erio]

the mechanic sais that after changing to another coil the car started.
I have a foulty coil that produces spark.

looks like im im the market looking for bosch 901-602-502-00 coil.
Anyone have one for sale ? with shipping to Chicago and payment via paypal ?

[Uncle Enzo]

I think you can pick up a brand new MSD coil from our host for under 60$.

[erio]

will it be safe to work with stock CD ignition Unit ?
is there any possibility that if i use wrong non original coil the cd unit will get damaged (cd unit is before coil)

do i risk only not starting or poor performance by getting aftermarket coil ?
i can buy coil that has the same parameters (like resistance)
what resistance has this fully operational stock coil ?

(40,000 Volts, 3 Ohms), ??