|24/02/2004 08:29:06||Steve||Dear Saabers,
I've recently purchased a Saab 96 from my father and it runs very nicely at speed and under load, but when it is left to idle the engine misses intermittently. This is made worse when you rev the car and then take your foot off, it almost cuts out before settling to idle. The car has just been serviced and has new plugs, points, air filter etc... I tried increasing the idle speed but it has really only masked the problem.
Any help would be appreciated.
|24/02/2004 11:33:08||Senor Burt||Check fuel idle mixture & timing.
If you have a spark tester (thing that goes between end of lead and plug, lights up when it sparks)use that on each cylinder in turn to see if it is sparking intermittently on a particular cylinder. Could be a dodgy HT lead maybe.
Was it doing this before it was serviced? Could be a faulty plug or something else that was replaced.
Have you replaced rotor and disi cap?
Just guessing really, could be something else mechanical, but fuel/ignition problems are usually favourite in cases like this.
|24/02/2004 13:37:57||steve h||yet another steve. What were our parents thinking!
I agree with senor burt. It could be one (or a combination) of many things. Start with the things that cost no money like idle mixture and carb float level, then move through new leads, electronic ignition (Aldon ignitor is fine) to eventually end up at new carb.
I would put my money on the ignition if it has just had new points as they can be a bugger to get right. If the car is a long term proposition, fitting electronic ignition is a good idea as you never have to adjust it again and the car always runs at peak timing. Havent touched mine for 50k.
But still, it could be any of the other things as well.
|24/02/2004 16:47:14||Steve||Thanks guys, this is a big help.
I like the idea of using a spark tester to check each plug - I'll do that tonight.
Although the car was serviced I'm not sure what was done, the plugs look quite new but things like the oil filter look old, so it's quite possible the distributor and points need attention.
By the way I've been reading old discussions about electronic ignition which is something I would like to do, so Ive been comparing the 'Lumenition kit' with the 'Pertronix kit'. I understand that one is optical and one magnetic. But the Pertonix kit seems simpler and cheaper and has less components than the Lumenition kit so why would I go for the more expensive option ? - am I missing somehting ?
|24/02/2004 17:06:07||Senor Burt||I've got a Lumenition on my 95. Bought it at an auto jumble. Took me 10 minutes to fit. Ran perfectly first time.
Don't know about the Pertronix.
It's essential for the rotor and disi to be in good condition. If they look old, replace them anyway. They are an off-the-shelf item at any car parts shop, and cheap. If the points are old, replace them as well.
Who serviced it? If it was a garage, it's fairly safe to assume that something has been messed up in the process. Unless it was a mechanic you know to be trustworthy.
|25/02/2004 13:53:01||steve h||I have two v4s. One has luminition, the other Aldon ignitor (magnetic in the dizzy). The only differnce is the Aldon is £50 cheaper and is completly contained in the dizzy, where as the luminition has a external box to fit somewhere. Im sure there must be a performance benifit with the lumintion, probably over 6000rpm, but i'll be dammed if I can tell the difference. I only bought the luminition because the Aldon wasnt available then. Luminition now also do a similar magnetic system.|