Griff running very poorly...

[Painey]

My Griff has recently started running terribly and although it's booked in at Austec for three weeks time, can anybody give me any tips as to whether it's something simple that could possibly be fixed before then?

It starts fine and all dials seem ok. From the outside there's nothing untoward and I haven't messed around with anything at all. But it's started occasionally misfiring and also being very stop/start on light throttle. It's now also starting to pink above about 4k rpm and I've already had Austec knock the ignition back to sort this out. When it does start to do all this, and it is quite intermittent, the idle goes haywire too. Plant the clutch to change gear and the revs drop very low, 2-300, almost stalling it. Then when you engage the clutch once more it's very hesitant unless to pull away unless you really floor it.

I'm totally lost as to what it is. The plug leads are fine - magnecor ones less than a year old and it had its 34k service done when they were fitted. I haven't looked at the stepper motor as it's always ran perfectly so I'm reluctant to start mucking around with it. I've never had any problems like this with it before and although it's not going to cause me to lose any sleep, it's bloody annoying when it starts doing it!! Any ideas/recommendations would be greatly appreciated!

Cheers - Chris

[Ballistic Banana]

Stepper motor is the easiest thing to clean(just dont do it up to tight as they can break easliy) that gets dirty and sticks causing these sorts of problems. Along with the throttle butterfly in the plenum, which can be cleaned by taking the inlet hose off. No cost just time, and could possibly cure it.

BB

[Mark Adams]

This has the unpleasant cheesy whiff of a dud airflow meter to me.

If you are near to Austec, I suggest you call in and get them to try one of their known-good ones on the car.

[Mark Adams]

If you're not near to Austec, let me know and I'll tell you how to do a basic check with a digital voltmeter.

[Painey]

BB / Mark,

Thanks for your help. I think I'll check the stepper motor out this weekend when I've got some time on my hands. As for the airflow meter, Austec are quite local to me so visiting them isn't a problem. Mark, I was hoping to fit a new Bosch AFM next winter, plus ACT plenum etc etc and have you chip it at Austec anyway. Cant afford to do it just yet though so I hope that's not the problem!

Cheers - Chris

[GreenV8S]

Mark Adams said:

If you're not near to Austec, let me know and I'll tell you how to do a basic check with a digital voltmeter.

I'm nowhere near Austec and got a suspect knackered AFM - any hints on this basic test Mark?

[Ballistic Banana]

Hey Pete Check out the rpi site, the basic tests are on there www.rpiv8.com/carbs-2.htm#setting-up.. would have thought you'd have known that although that is testing to set it up!!

BB

[mongoose]

Ballistic Banana said:

Hey Pete Check out the rpi site, the basic tests are on there www.rpiv8.com/carbs-2.htm#setting-up.. would have thought you'd have known that although that is testing to set it up!! BB

what a coincidence.i posted that link on the chim forum earlier also.its a great site for v8 info innit.harry w has posted a little bit of usefull additional info on throttle set up as well.its all on the thread titled 'air mass meter adjusting screw'.

[GreenV8S]

Yes I know about the trimmer (although mine's the later 20AM meter) but that doesn't help me confirm whether the thing is knackered.

[tgriff]

Have to go along with Mark on this check your air flow meter , sounds duff, first check the multi pin plug is home. Its drastic so either fuel or air , not mechanical damage
next check fuel supply not put anything silly in the tank ?
good luck
Steve