no spark

Malc458 · Jul 30, 2013

My SC will not fire, yet: -

1) all fuses in box under bonnet are ok.
2) tank full of new petrol.
3) ignition lights are on.
4) engine cranks but does not fire.
5) full pump runs
6) can smell petrol from exhaust.

RAC man says that the coil has no input or output current.

Can anybody tell me why it wont start?

timbarber · Jul 30, 2013

Hi Malcolm

I'm no expert, but it sounds like it could be a problem with your spark box. It may just be connections, but I've had to replace mine in the past - unfortunately they're not cheap items [

]

Malc458 · Jul 30, 2013

Hi Tim. Thanks for the reply. I'm no expert either - so where /what is the spark box?

dij999 · Jul 30, 2013

Left side of engine compartment against inner wing panel behind the plastic cover.

There are reconditioned ones but still not cheap though considerably less than new - I
replaced the one on my (now sold) SC a few years ago.

Can only suggest doing a google search on it - I don't have the receipt from the company
who supplied as I passed on everything to the purchaser.

Dave Jones

930T · Aug 1, 2013

Hello, my 930 has the same issue at the moment, and the popular culprit is the spark box or Bosch CDI. The link attached will give you some background reading. I'm going to start having a look around at the weekend, one first thing to check is to open the engine lid, turn on the ignition, then head around the back and listen for a high pitch whine from the LH corner under the plastic cover. If you hear no whine then almost certainly there is a problem with the spark box or the relay that feeds power to it. I'll let you know if I make any progress.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/547032-sticky-common-answers-why-my-car-doesnt-start.html

dij999 · Aug 1, 2013

Further to my previous reply - it was John Speake of JDS Porsche (Google them) who repaired mine.

There are other options - mentioned in the Pelican website and probably by John Speake - with varying
impressions of suitability.

Dave Jones

Malc458 · Aug 1, 2013

Hi Dave.
Thanks for that; i will get in touch with them.

GeoffB · Aug 1, 2013

Might also be worth just checking the plugs through the bulkhead just above the pedal box. I recall on my old SC pulled up for fuel and would not fire, tried everything and then found I had dislodged one of the plugs with my foot. Worth just pushing them all home to make sure good contact
worth a try, good luck with solving the issue

dij999 · Aug 2, 2013

Lost wipers that way once but was not aware fuel or ignition connectors were on that side of the bulkhead.

Dave Jones

Malc458 · Aug 2, 2013

Spoke to Reg Sec and he thinks that if there is a noise from the box and no spark, it's possibly kaput! Also spoke to JDS Porsche and he can test for £30.00 and / or repair for £100 + vat + carriage. Sounds ok.

Cheers Malc.

dij999 · Aug 2, 2013

Big saving on Porsche supplied replacement.

Hope yours is repairable

930T · Aug 8, 2013

In case anyone is interested the problem was with my Spark Box (Bosch CDi Unit). I found a contact for repairing the original unit as follows:

http://www.911-hkz.de/

Google can translate the page if required.

The Engineer is Lutz Gerberding, and he seems extremely knowledgeable about these and other units associated with our cars. Lutz speaks good English if you want to email etc.

After looking at my spark box he emailed me as follows:

"your cdi-unit has been repaired and will be shipped back today.

The ignition capacitor (that holds the 400V ignition energy) was defective with a shortcut. The shortcut has blown several other components, that deliver the 400V high voltage.

There are 3 major reasons for a problem like this:

1. Usage of a newer ignition coil type Bosch 0221121001 with silver housing, Made in Brazil , charge number 908 on the bottom side. Use the Made in Germany historic original instead (black housing) or use BERU ZS-109 (without a resistor in series).
2. Burned noise suppression resistors (spark plug connectors, distributor finger, plugs on the distributor cap, plug on the ignition coil). The resistance of this components should not exceed 6000 Ohm, each.
3. Any other breaks in the secondary ignition system, like broken ignition cords, loose spark plug connectors, "¦

In all these cases the ignition energy can´t flow over the spark plug and hits back into the cdi-unit instead. After this has happened a few times, the ignition capacitor will fail.

So the repaired cdi-unit comes with an integrated overvoltage suppressor, but this only protects the cdi unit and doesn´t solve the problem.

If you can´t find any reason that was responsible for the problem, don´t worry to use the repaired cdi-unit. Then watch out for any sparks on the top of the ignition coil (don´t touch anything). If you can notice sparks, the problem is still not solved."

He returned the unit to me in 2days, cost Euro260. Well recommended.