Still sluggish at start

jbjs40 · Post by **jbjs40** » 27 Feb 2013, 10:31

I posted awhile ago about the same problem. I just had the brakes done and they are working great again. I just replaced the plugs and the engine seems to like them. But the sluggishness at start up is still there. It goes away after a mile or so but it is really annoying since the car itself looks great. After it warms up its great. But I moved to Florida and I do not get as good MPG's as I did in Georgia. I use only Shell Premium. 93 octane or better when I can find it at the track. I was wondering if this could be a fuel filter related issue? Open to any and all suggestions. The engine is throwing a code about the cat but I am looking into that as well.

jbjs40 · Post by **jbjs40** » 18 Sep 2013, 21:40

Ok months have passed and no reply. Maybe I am not clear? Anyway the idle control valve is now the main culprit. The coolant sensor may be out too since the fan has been coming on AFTER I turn the car off, and the fan runs for a long time. It is possible it is draining the battery. The sluggishness is no longer the problem. If I can only get this thing to idle. It stalls at the light after the rpm's drop to nothing. It starts right up every time. It idles very LOW. and when I lift OFF the gas pedal the car idles down very quickly to the point of stalling. Very dangerous. Traffic is murder here.

Post by **jblackburn** » 19 Sep 2013, 04:56

Clean the idle control valve with carb cleaner. This will unstick any stuck flaps if there are any.

That coolant temp sensor sounds bad if the fan is running real often after you shut the car off. My car has done that twice in its whole life. Would explain a lot of the starting/idle/MPG issues as well.

jbjs40 · Post by **jbjs40** » 19 Sep 2013, 08:27

Thanks I am cleaning the IAC (idle control valve) right now. The sensor I will have to order as local parts stores do not carry any. I think I found one ( meyle) for around $20.00. If so then I am buying it. Anyway thanks for the response. I spoke to a Volvo mechanic and he said pretty much the same as you. These cars are great by the way. I have had a Honda civic in the past that I hot rodded back in my youth and I dumped money into it only to be blown away by some guy in autocross competition with a stock VW GTi. In total around $20,000 was spent on this Honda. What a waste. I really believe that this Volvo is a keeper. And I only spent $5,000 on it. I am the second owner and it was maintained religiously.

jbjs40 · Post by **jbjs40** » 19 Sep 2013, 10:54

OK I just spent my morning getting the idle control valve out and cleaned. Put it back in and still does the same thing. So cleaning the idle control valve did nothing. At least I know it is clean, right? Next option? Could that coolant sensor problem cause idling issues?

Post by **matthew1** » 19 Sep 2013, 12:00

I don't know much about the 40 series, and don't know the liklihood of the coolant sensor as the cause.

Have you looked at this: https://www.matthewsvolvosite.com/what-is-stage-0.html

Comparing what's there -- as it relates to fuel/spark/air -- to your S40 might give us ideas.

jbjs40 · Post by **jbjs40** » 19 Sep 2013, 12:34

My S40 is at stage zero. Oil and trans fluid and brake fluid along with radiator fluid have all been done this year. New spark plugs and always the use of premium fuel. Synthetic oil (Castrol) only is used. K&N filter. OEM oil filter. Fuel filter, and some new fuel lines and radiator hoses.
The stalling at idle problem occurs now always. And when engine is ice cold the fan continues to run for a long time. I can turn the key to the on position and the fan will start and not stop for a good 5-10 minutes after turning it back off. Can this coolant sensor be the problem all along?

Post by **matthew1** » 19 Sep 2013, 12:44

Did you get the code?

jbjs40 · Post by **jbjs40** » 19 Sep 2013, 14:51

cannot drive it to get the code. car parts store will not loan the reader. last codes this car threw were catalytic converter p0420 code. Got that resolved.

Post by **matthew1** » 19 Sep 2013, 15:02

Code readers are $16.77 on Amazon. I've had that model for years, it's rugged and simple.

It'll save you from throwing parts at this problem.