Hi all

My 1018SR starts good, runs good but it idles high. I don't have a tach but it sounds high. The car sat during cold months in MD. It didn't have this issue when I first got it. I need help. Thank as always.

No codes; 111 ran the test three times
New spark plug, cap, rotor and coil
Thermo paste on
Cleaned throttle body (clicks) & idle control valve carefully
No leak on intake hose & elbow hoses
New fuel pressure regulator; fuel leaked

Runs good & starts good
Fuses looks good
Ground points are good
Intank pump is working

Sprayed CRC cleaner to check leaks; fuel injectors, most of the hoses

I read the thread below & the set screw height and linkage length are good.
http://www.brickboard.com/RWD/volvo/1548016/220/240/260/280/high_idle_111.html

With MAF/AMM unplugged, the car runs rough but idle better and threw 121 code

Previous 1018SR maint. history
http://www.brickboard.com/RWD/volvo/1555089/220/240/260/280/re_93_245_auto_previous_maint_history_1st_owner.html

If everything is as air tight as you say it is then it is getting excess air from where it is suppose too!

To explain, I mean from the throttle plate being to far open or the IAC is sticking open or not closing the way. I like a one-third turn up only after touching the stop lever. If you screwed it too much then you will have to reset the swithch to just click when it wiggles open or you may have hesitation on take off.

Two places your checking did not mention was an air leak from the cabin side controls or the brake booster line or a cracked check valve grommet. Actually I have seen the body of the check valve crack. Probably from a stiff or too short of a line to the engine.

Disconnect, plug or squeeze off what ever you have to slow it down as a start.

Phil

Hi Phil

"Disconnect, plug or squeeze off what ever you have to slow it down as a start."

Thank you for advise. This is what I did today.

Swapped an intake hose; didn't change.
A cracked hose found, one that connects flametrap to oil separator, wrapped with silicon tape & still no change.
No visible cracks on check valve grommet.
Applied pressure/pumped brake, started the car & the brake pedal dropped 1 to 2 inches.
Unplugged IAC; no change, how do I know if this is bad?
How do I check for air leaks in the cabin?

The throttle body plate/butterfly is closed, I didn't have to make any adjustment.

Like I said before, the air must be getting in at or behind the throttle plate. Also please remember I do not have a 93 model, only a 91, so things I say may not be so!

My car has an EGR does yours? You might need to look for pins holes in the intake pipe or loose connection fittings down at the EGR.

On the flame trap idea, there is thumb sized hose that goes in front of the throttle plate and connects to the intake hose. That should not cause a problem but we know it screws up the AMM and overall run mixture of the engine.

I do believe that there is a small vacuum hose that tees off the flame trap screen and goes to the intake manifold. Was that one good? I think it could leak enough "free flowing" air to raise the idle slightly but there is an orifice diameter that meters that amount of air from the flame trap circuit.


The cabin supply vacuum hose can be removed and the port on the intake plugged. This should eliminate and tell you if there was a problem in that direction.

Same thing goes for the brake booster hose. Just do not drive it that way.

The evaporative fuel canister hose would allow air in through another metered port right at or very near throttle plate. I think there is a check valve built onto the canisters top. It vents gas tank fumes, at certain times, into intake. I have found this hose connection, down at the canister, can come loose while yanking and pulling with the intake hose. If the end on it gets old, it can be pulled off. Might worth checking up on. The can is below and at the bumper level of the divers side fender.

On the IAC, of the nineties cars, they have a return spring that keeps or should keep it closed, until starting. The ECU powers it open.
If the ECU was telling the valve to open it up, above the closed shut range, when you unplugged it it should have slowed the engine slightly. Of course, if its getting to much air around the IAC the ECU would be already letting it close. So nothing should happen.

I think the recommended method to stop air from going ther is to put a plastic bag loosely over the end of the hose and put in back on the connection. That will stop all or any air through it. It should be harder to start since the only starting air would have to come from the foot opening the throttle slightly. The engine should not be able to idle without the IAC. At least that is the purpose I perceive it to do. (:)

If you take it off it can be powered by a nine-volt battery to see if it response is smooth.

Phil

Hi Phil,


"My car has an EGR does yours? You might need to look for pins holes in the intake pipe or loose connection fittings down at the EGR."

No, this car doesn't have an EGR system. She spent her entire life in MD.





"On the flame trap idea, there is thumb sized hose that goes in front of the throttle plate and connects to the intake hose. That should not cause a problem but we know it screws up the AMM and overall run mixture of the engine."

I replaced it with new hose. The old one was in bad shape




"I think the recommended method to stop air from going ther is to put a plastic bag loosely over the end of the hose and put in back on the connection. That will stop all or any air through it. It should be harder to start since the only starting air would have to come from the foot opening the throttle slightly. The engine should not be able to idle without the IAC. At least that is the purpose I perceive it to do. (:)"

Good idea!




"On the IAC, of the nineties cars, they have a return spring that keeps or should keep it closed, until starting. The ECU powers it open.
If the ECU was telling the valve to open it up, above the closed shut range, when you unplugged it it should have slowed the engine slightly. Of course, if its getting to much air around the IAC the ECU would be already letting it close. So nothing should happen."

When I took it out for cleaning, the valve wasn't closed all the way... Can I just hook up to a 12v battery for valve opening/closing?



The car caught fire yesterday, I really didn't have a chance to look at closely but I will do a write up & post up pictures later. Maybe you can help more. Thank you.

Yes, you can use 12 volts from the battery. I agree that it is more convenient.

I recommend using the nine volt as the action will be a tiny bit slower and it allows me to observe any dragging. It also mimics the conditions that its will be under when the car starts because the system voltage drops when cranking.

Sorry to hear about that fire. Looking forward to the story.

Phil

Hi Phil,

Thank you. I am not happy that she caught fire but it could have been a lot worse. I can't ask for more. I will write more as I take a closer look.

Last winter, one of my friend broke his ribs, his doctor was able to find "hard to find" pancreatic cancer during his treatment. He went into a surgery very next day and he now has more time to ride bicycle with us. I felt bad in the beginning but I also think he's very fortunate. He's in his 70s. :-)

Yikes and sorry about the fire!

I was going to say I was chasing a high/rough idle and similar symptoms on my 945. I cleaned the IAC well, cleaned TB, checked vacuum lines, etc. Finally, I replaced the IAC and the car now idles perfectly. I opened up the old IAC and found a chunk had broken off on the valve that I couldn't see when cleaning. That spring mentioned above also didn't look to be functioning properly.

If you've got someone with a known good IAC it might be worth testing it out to see if that's the problem.

Hi Nick,


Thank you! That's very nice of you. She and I did survived, thanks to my wife. LOL!!! Please read my write up, will be doing later.

I will look into my IAC as you have suggested. Thank you.