93 940 Turbo - rough idle

[me]

Just bought a 93 940 Turbo from an auction: 131k miles.
The idle was cranked up to make it idle more smoothly.
I cleaned the throttle body and adjusted the idle per:
http://www.ipdusa.com/ProductsCat.aspx?CategoryID=511&NodeID=767&RootID=629

It still runs rough.

Could it be the idle switch?
It has 3 contacts, when I test it with a continuity checker it makes and
breaks between two of the poles. But there seems to be no action on any
other combination of terminals.

Any other suggestions.
Thinking of replacing the injectors but thats a few more $$$!

Thanks
Berk Ott

 

[Peter Milnes]

Try cleaning the Idle Air Control Valve. This is likely to be the cause of the
rough idle. We, on this side of the pond, follow the recommendation to
thoroughly clean the complete inlet tract every two years. This tends to negate
such problems.

Cheers, Peter.

: Just bought a 93 940 Turbo from an auction: 131k miles.
: The idle was cranked up to make it idle more smoothly.
: I cleaned the throttle body and adjusted the idle per:
: http://www.ipdusa.com/ProductsCat.aspx?CategoryID=511&NodeID=767&RootID=629
:
: It still runs rough.
:
: Could it be the idle switch?
: It has 3 contacts, when I test it with a continuity checker it makes and
: breaks between two of the poles. But there seems to be no action on any
: other combination of terminals.
:
: Any other suggestions.
: Thinking of replacing the injectors but thats a few more $$$!
:
: Thanks
: Berk Ott
:

 

[~^ beancounter ~^]

a fine auto...i got mine on eBay also...these leiile babys
fly when set up right.. ;-) anyway... 1st make
sure you have no leaking or cracked hoses...esp the large
turbo hoses...this will %$#@ the running BIG TIME...check
vacume hioses as well...(any craks, splits, etc.)..i am not
sure how to check the electrical swtich...that is when i am
visiting my volvo shop...i did learn how to read and dump the
error codes...that was quick and easy...i agree to look at the throttle
body...make sure that is workin'...then...there are a few electrical
sensors to check and verify...you may want to unhook the battery and re set
the computer...i know sometimes this will help my low idle...and poor
low end , off the lice accrleration settings...anyway...good luck w/the940t..
with some $$ (2-3k) you can get these older volvos to 0 - -60 in
6 sec or < ...

 

[Dan Harrington]

I would suggest diagnosing injectors, locating any vacuum leaks from
poor seals and O-rings. What about temp... sensors? 02 sensors? plugs
and wires? Do you have a manual that explains diagnostic procedures? If
no, recommend strongly that you invest in one. I have complete set of
OEM manuals for my 245 and if I hadn't invested in them I would have
been forced to unload my brick along time ago. Oh! what about the turbo,
is it running properly?

Hope I have been a little helpful

Dan
1987 244 DL 189,000KLMS
1988 245 DL 242,000KLMS
currently replacing squealing blower motors in both cars. Been doing it
for 3 days now, removing the entire dashboard, steering wheel, and 2
front seats makes the job easier, and found small window leaks in one
car and a broken defroster door actuators in the other. Plus removed
hordes of debris which had to have been blocking out fresh air entry to
the passenger compartment.

 

[Beast]

Check the spark plugs and HT leads as well.

Keith Beast
E14 4NS Docklands