1982 244dl 4 door 4 speed 4 cylinder

Nothing was changed in months then friday the car wont idle, now it stalls

Start it up and it idles at 900 then it will sound as if its missing and drop to 700 then back to 900 three or four times then it will drop almost to 0 then zoom to 1500-2000 then idle for a few seconds at 900.

It got a LOT WORSE after I installed a new fuel filter while trying to figure this all out

If you actually drive it, runs great, no problem, but wont idle for anything

18 months no problem then out of the blue this started happening.

 

1982 is an early year... is that K-jet aka CIS injection, or is it early LH-II electornic injection? I know next to nothing of volvo k-jet systems

if its LH, there's an idle switch on the throttle body, this has to click 'closed' when the throttle is completely at idle and click open when you barely bring the throttle above idle. when that swithc is 'on', the idle control system comes into play... under the intake manifold and throttle body is a 'IAC' or Idle Air Controller, this is an electrically actuated air valve that has a rubber hose about 1/2" in diameter to either side of the throttle body, and an electrical connector on top. with it disconnected, the engine fully warmed up, and all accessories switched off, the engine should idle at about 500rpm, whihc it plugged in, it should bring that idle up to the 700rpm spec, and hold it there, even if you turn on accessories (headlights, air conditioniiing, whatever)

probably the first thing to check is the condition of all the rubber hoses on the intake side of the engine. vacuum lines, the main air duct between the MAF (mass airflow meter, aka AMM), and this idle air valve. any air leaks drive the system nuts. if all the rubber is in good shape (replace what isn't with new!), then its a good idea to take the throttle body off, and clean it out with carb/throttlebody cleaner spray, to remove any sticky goo thats accumulated around the throttle plate, and make sure all the tubes that are on it are open and clear. next, remove and clean out the IAC too, again, hose it down with carb/throttle body cleaner spray. if you can rig up some kind of source of 12V to its two pins, it should open, and when you disconnect it it should close, briskly, not sluggishly. now, reassemble all that, using new rubber anywhere its old/hard/cracked.

hopefully everything is happy.

btw, changing the fuel filter was probably not required, unless it was seriously flugged up, and if it was, you probably need to flush out your gas tank and fuel lines, too.

 

Your car is k- jet or CI in volvospeak. Probably your top things to check are:
- leaking fuel lines (check those filter connections)
- leaking or continuously operating cold start valve
- air leaks
- control pressure regulator fault

I think your car has a CIS or constant idle speed system (not related to VW CIS)
It is displayed in the following k-jet link.

The other link shows the how- to of checking the system although it is for VW rabbit, so you would have to transpose some information from the k-jet pag



K-Jet.org | K-Jet In Detail

1983 Volkswagen Rabbit Poor Performance and Stalling


I'd check that filter connection first, as you said it got much worse after the change

 

I have seen conflicting information on whether your car has an auxilary air control valve or the CIS system with an idle air control valve. This link shows both:

SKANDIX Shop - Search: idle air control valve

Either one would be under the intake.

 

i think its a sticking intake valve

1- car idles fine cold and warm, you have to run it on the road and get it really warmed up, then it starts the idle problem, but I also feel an occasional HITCH while driving down the road

After its good and hot, sitting idling, it will drop rpm then surge up to 1500 OR just cut off

vaccuum gauge dhows good vaccum then it drops a tad still in the green but lowest part of green and it will either drop and recover or drop and stall

starts right back up

at the exhaust it has a miss when this happens, and i think it sucks my hand toward the pipe when it misses

 

 

FIXED

6 12 oz bottles of techron and 70 to 80 mph for 100 miles accelerating hard uphill to load it down and heat it up.

4th gear 4,000 rpm

idles like a kitten now

 

sidenote

PRIOR TO THE TECHRON SOLUTION

i started car dead cold let it idle, ran fine for 2 hours (let it idle never drove it, 2 hours), then once it got as warm as it was gonna, it started breaking down while idling

that convinced me it was not underhood stuff, but sticky valves when fully warmed up

 

ALSO
1 gallon of seafoam in oil fuel and vacuum did nothing to help

nor did marvel mystery oil

techron

 

after putting all that crap in there, when you've run a full tank of plain gas through, you should change the oil and filter.

I'm questioning the stuck valve diagnosis... a valve stuck open would have zero compression in that cylinder. a valve *can't* stick closed unless the valve stem and camshaft are badly damaged.