tune up for 81 240 DL

Dan N · Post by **Dan N** » 27 Aug 2006, 18:18

Hi
First time on here.
I'm trying to do a first time tune up and am dumb to the core.
Runs quite rough now misfiring upon starting, completely unreliable so belatedly I'm doing the tune up.
Distributor cap is ok, changed the plugs, rotor alright, points pitted so installing new one. Got that far, but, with Chilton now useless...
Question:
Is there a website / anyone out there who can lead me step by step through use of a dwell meter to set points gap?
if the tune up doesnt' work will have to go to replacing carbureator... any advice on this.
many thanks
Dan.

Post by **billofdurham** » 28 Aug 2006, 16:27

The points gap is initially set up using a feeler gauge and the dwell angle is a check to ensure it is correct. In my 40+ years of driving and maintaining my own cars I have never checked the dwell angle.

I would suggest that you do all the work you have planned, leaving the carb alone for the time being, then find an independent garage with electronic testing equipment e.g. Krypton, Sun and have them check all of your settings. This was what I always did when I had cars that, like yours, were designed for DIY maintenance. I had it done once a year and the outlay was definitely worthwhile.

Bill.

Sutek42 · Post by **Sutek42** » 28 Aug 2006, 19:00

Distributor cap might have a hairline crack in it. Change it. Cheap enough.

Dan N · Post by **Dan N** » 28 Aug 2006, 20:27

many thanks.
I'll give it a try

LaRy · Post by **LaRy** » 29 Aug 2006, 11:42

How do you know the rotor is alright? Change it, it has a resistor inside that could be worn out. Volvo is using an expencive rotor with mechanical overspeed protection. A normal driver will not need this protection and then you could buy a much cheaper standard rotor.
Change also the cables for the spark plugs.

So my suggestion is to change spark plugs including the cables, distributer cap including rotor. Change also the cable between the ignition coil and the distributer. Actually, those cables should definitely be changed every 10'th year. Then, if it is not working we could continue the discussion what to look for. I have good experience from Volvo's with caberuators.

A feeler gap should be just OK for adjustment. If the gap is correct, the dwell angel will be good. In a 4 cylinder max 6000rpm engine, the value of the dwell angel will not be sencitive. If it is to small, the affect will just come close to maximum rpm by missfiring, because the ignition coil will get to little time to recharge before next spark.

Describe also the problem, it runs quite rough. What do you mean? Is it missfiring at one cylinder or is it just bad. Listen to the exaust outlet, one cylinder or general pluddring.