1984 245 GLT Rough Idle Problem

My 1984 Volvo 245 GLT wagon has a rough idle. I replaced the plugs, cap,
rotor and tried a bottle of fuel injector treatment to no avail. I recently
purchased this for a second car at a local charity auction for $500 USD and
did not have an opportunity to drive the car first. There were no records
or books with the car but it looks fairly well cared for in and out.

This is my first Volvo and I'm not very familiar with them. Other than the
rough idle, the car runs and drives beautifully with approx 210K miles, no
warning lights, odd noises, or problems with the turbo etc... The dash tach
says it is idling about 850 rpm or so, and will smooth out briefly after a
run on the freeway. Any help is greatly appreciated.

Thanks,

Stacy
Puyallup, WA

 

Rough idle is a tough one. Can be caused by vacuum leaks, low
compression, clogged/dirty fuel injector(s), clogged ports in the
throttle body, and other things. If you're new to Volvos, I strongly
suggest finding the 240 FAQ (google should come up with it) and go
through that. Clean or replace the flame trap, clean the throttle body,
pick up a Bentley 240 manual, these are great cars, but being 25 years
old it'll need a few things to get it into shape.

 

Try pulling off each plug wire one at a time to find the cilinder
missing, maybe put it on a scope or do a compression test. Does it
have 4 coils maybe one is bad, mine has one bad. One bad injector
maybe.

 

No, nothing from 1984 has four coils, it uses a conventional ignition
coil and distributor having mechanical vacuum advance with an electronic
box to drive the coil. I had missed that this is a turbo, GLT is a trim
level, the cars that said GLT on them are essentially the same as the
turbo model, but without the turbo motor. At any rate, 240 Turbos all
had K-jet mechanical injection which is very sensitive to vacuum/boost
leaks and fuel contamination.

 

A good source of information for Volvo owners is
http://www.volvoforums.org.uk/

More specifically for owners of 200 series ( I have 2 ) is
http://www.volvoforums.org.uk/forumdisplay.php?f=11
The message archive for 200 series goes back years and is searchable in
Forum Tools.
The forum is run by Volvo Owners Club ( UK ) though there are international
users too.
If you sign up to the forum ( it's free and you don't have to be a member of
VOC )
you could post your query there and there are lots of helpful and
knowledgeable forum members to call on.

It's my first port of call if I have a problem that I can't resolve myself,
I pop in once or twice a week anyhow.

I don't remember the forum being mentioned on this newsgroup before but I
highly recommend it.