Volvo RWD 200 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 10/2012 200 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

Idle is erratic while stopped. 200 1983

Howdy folks,
1983 240, 2.0 engine, 280000503 ECU.

Car was parked for the winter. I started her up last week and
she began to have an erratic idle. She drive well otherwise.
It is when I am at a stop, in gear or in park. She sits fine
for a few seconds then she begins to change her idle both and
increase and decrease. While I drive slow I can feel the idle
increase and decrease slightly.
Very seldom do I get a stop sign or light that is trouble free.
If I do not give her fuel she will eventually stall out.

I have check for any air leaks and fixed two small ones. Fuse 13
is good.

I have removed and cleaned the Air Idle Control, it seems to be
humming fine.

When I remove the hose that leads to the AIC I can
feel the suction in the hose both when I have the engine revving and
upon idle.

All the injectors can be heard clicking.

Both fuel pumps can be heard humming.
Fuel is fresh.
Could a plugged injector be my problem.?

Plugs, wires, dist. cap and rotor are new.

I'm in the thought that the ECU is going out?

Any advice is appreciated,

Joseph in New Mexico








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Idle is erratic while stopped. 200 1983

    Turns out my fuel pressure regulator was leaking.
    I pulled the hose off of it and fuel spilled out.

    All better now, after replacement installed.

    Thanks for all assistance.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Idle is erratic while stopped. 200 1983

      Hi,

      That is good it was the FRP, as it helps explains, what to me, was a either a lean mixture misfiring or an erratic idle speed cause by a gulp of fuel into the intake manifold from the hose.

      Thanks for the final report on the outcome!
      That will help everyone on the BB.

      Phil








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Idle is erratic while stopped. 200 1983

    Additionally:

    Sometimes while at a stop and idling she
    will purr like she used to and then about
    5-10 seconds later the skipping of the idle
    returns and I have to give fuel to keep her
    running until it's time to take off.

    Throttle Body was cleaned a year or two ago.
    I felt inside the throttle body with my finger
    and it is still clean.

    Engine is missing both when cold or hot.








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Idle is erratic while stopped. 200 1983

      Hi,

      Double check the accordion snorkel tube behind the AMM as there might be a pin hole in a volute or a loose fitting clamp. Put a fluorescent light tube up the middle and flex the hose in a darkened place.
      I found that to be the case, when I had an unpredictable idle shake or stall, at a stop light.
      I believe it was do to the engine twisting just enough while coming to a stop, that it opened up a crack temporarily.
      Sometimes there can be a partial crack around one of the nipples that go off to a hose. Either of the two hoses can upset the mixture and make it go into a lean misfire situation.


      Phil








      •   REPLY TO THIS MESSAGE    PRINT   SAVE 

        Idle is erratic while stopped. 200 1983

        Hi MachineMan,
        Thanks for the tips. I did find wear holes in the accordion hose yesterday and I repaired them.








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Idle is erratic while stopped. 200 1983

    Hi,

    I can say it's not good to let gasolines to age in a cars gas tank! There is a lot of air above the gasoline in a 16 gallon tank that will cause the fuel to oxidize or breakdown more quickly and the octane drops down with this aging because gas is not a wine!
    You can slow down the rate of decomposition if the tank was completely topped off when it was stored, in a garage, that keeps the temperature more constant.
    The same thing should be done with your gas cans, if they are used storing fuel for the same amount of time.

    So, You have new spark plugs in there and this engine is in a good tune up condition.
    Did you do the replacement of parts or did someone else do it?
    Do you know if their gap is set correctly?
    Some people are told by the parts counter clerks, that they come set from the factory in its little box if you are lucky. Bubble packs can get dropped from a hook and stuff found dropped on them to add insult to a possible injury.

    I never believe that they are going to follow quality control that close to each box! One heat range of a spark plug can go into too many different kinds of compression engines, using different ignition voltage methods, timing control algorithms and so forth.
    Each car maker can use different fuel minimum octane ratings.
    Volvo calls for a 89 minimum octane rating in any red block.
    OLD gas can be the issue for a while if the tank was left near empty.

    A misfire, even a slight one, will be picked up by the rpm drop.
    The misfire results in a quick mixture changes from the ECU and that affects the oxygen sensor to respond so it can be called a self-tuning fuel management system.

    What is the age of the oxygen sensor?

    Does your car use a only slight amounts of engine oil? High oil consumption creates more carbon deposits.

    Look at the colors on each plug to be the same across all of the cylinders?

    Of course, this is my armchair recommendation!

    Phil








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Idle is erratic while stopped. 200 1983

      Machine Man - I did the tune up myself and gapped the plugs at 28. By now I've refilled enough to where the fuel is all new. I replaced the oxygen sensor today, but it didn't help. She does not go through much oil.








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Idle is erratic while stopped. 200 1981

    At idle and you don't touch the gas peddle at all, is the engine missing or running rough when the idle is low and then runs smooth when the engine speeds up?








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Idle is erratic while stopped. 200 1981

      Hi 81 242,
      yes she is missing at low idle.
      And continues to miss until I
      reach about 15-20 mph. She runs
      smoother when rpm increases.







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.