Anybody know their old Vauxhalls?

[VAN with a PLAN]

I hope you don’t mind me posting a non T25 question on here but here seem to be lots of knowledgeable, hands on ‘old school’ bods on here so I thought I’d try and pick your brains!

For my sins I have been driving a Chevette for the past six years or so. At the start of the year I treated the Shove-it to a Powerspark electronic ignition module:

http://www.simonbbc.com/

Oddly it was then a little harder to start but, once running, idled much more smoothly and pulled much better and more cleanly, particularly in the low/med rev range. Overall I was chuffed – best £30 I’ve ever spent.
About 8 weeks ago it began to run very poorly - hesitant and occasionally backfiring under power but still idling nicely and revving cleanly if stationary. I spent almost a month trying all sorts of things looking at spark and fuelling. In the end I found it was running weak and tweaking the mixture made a noticeable difference. Swapping the coil cured the problem completely and for the last month or so it has been running better than ever. A few days ago the problem returned in a big way, again the car idles and revs beautifully on the drive but is almost undriveable once underway. I have not had the opportunity to try a third coil.

Does anybody here have any experience of the Powerspark module? I cannot fathom why I am suddenly consuming coils!

Any bright ideas gratefully received.

[pirate-pete]

Have had a couple of chevettes and a viva many years ago. Never had a problem with the coil but remember problems with worn out distributer shafts. I fitted some kind of electronic ignition (Luminition perhaps) which did improve things over the original breaker setup and made it a lot easier to set the timing with a strobe.

I think with the Strombergs the mixture setting is done at idle and then it relies on the needle profile being unworn to keep the mixture correct throughout the rest of the range. I think you are going to see at least some visible wear on the needle if you check it but I'm afraid I don't know how to tell if it is excessive and causing problems. Check the diaphragm too while you are at it. I had one tear once but can't remember the symptoms.

[ewenmaclean]

Hello,

I (very briefly) owned a 73 Victor which I loved, but it seemed everything I did made it worse (not the car's fault - I was just being incompetent). I fitted electronic ignition to it when the distributor needed replacing, and I seem to remember getting a higher rated coil but I knew nothing about it and went on the advice of someone else who knew - powerspark recommend a higher rated coil - did you already get one of these the first time?

http://www.simonbbc.com/ignition-coils" onclick="window.open(this.href);return false;

just a guess. Good carburettor advice from pirate-pete - I suppose the other question to ask is to check nothing do to with the HT system is getting wet...

hope you track the problem down

Ewen

(btw - I would be proud to drive a chevette )

[VAN with a PLAN]

Thanks for your replies. I have checked the diaphragm a few times. As you say, I'm not sure that I would be able to tell if the needle is worn but at 30+ years old I guess it is quite likely and I will look into the availability of a replacement.
Due to the somewhat intermittant nature of the fault I keep coming back to it being an electrical issue. I am going to try swapping out the coil again to see if that solves my problem but I would love to get to the bottom of why they are suffering!

The 1st coil to fail was supplied by Powerspark and matched to the module, this lasted around 9 months. I swapped in my original coil and all was good, but only for about a month and now the problem is back...

[bigherb]

Vauxhalls of the period used a ballast ignition system normally with a round ballast resistor bolted onto the + terminal of the coil. I may be wrong but later models like the Chevette used a resistive wire to the coil instead or that could have been Ford. Your problem sounds like you have the wrong coil fitted for the system. Check the voltage at the coil + terminal with the engine running if around 6V then you have the resistor still in the system and need a coil for that system. It could be the power spark coil was a 12v one which would explain the bad starting.

[VAN with a PLAN]

Thanks Bigherb. The original setup was exactly as you say - with a ballast resistor strapped to the coil and connected to the +ve terminal. The ignition module requires a non ballast 12V supply. I ran all the checks that Powerspark recommend prior to ordering the kit and was confident that the primary and secondary resistance were OK, and with the resistor removed my original coil met the requirements. For the sake of an extra £10 I thought I'd play it safe and order a coil with the module. I have not yet had a chance to try a third coil - This employment lark gets in the way of fun times a little too often doesn't it!

[VAN with a PLAN]

Many thanks to all who offered suggestions I finally tracked this fault down to an iffy low tension circuit. I have run a new feed from the ignition switch and all is great agiain - no matter which coil I try
I also took the oportunity to add a hidden inhibitor switch.

[faggie]

my friend has just fully rebuilt his chevette now fitted with a rover 3.9 and bike carbs it can been seen on u tube

[VAN with a PLAN]

Sounds very cool, I shall try looking that up