Question about 1994 Volvo 850

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My compression is a little off at full throttle, I think it might be either that my car is in need of a valve adjustment, my throttle needs to be cleaned, or there is something blocking the right amount of fuel from getting out of my fuel injectors.

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Clean your throttle body with some carb cleaner and then check your egr valve it may be clogged as well if it is take it off and clean the bottom hole where the egr seats it fills up with carbon deposits and blocks the flow also the egr valve may be clogged as well so clean it out iwth carb cleaner or soak in some gas so it can breakdown the carbon deposits it may have built to the point where it cause the valve to stay stuck open or closed.

Posted on Dec 11, 2008

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MY 98 HONDA ACCORD STALLS AT IDLE. RUNS GREAT OTHERWISE. WHAT COULD IT BE?


It could be a dirty throttle body, clogged fuel filter or a bad throttle positioning sensor. Also check the ECM to see if it is setting any useful diagnostic codes.

Jun 08, 2015 | 1998 Honda Accord

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1999 Porsche 911 Careers, no compression in cylinder 4. 91,636 miles, 3.4L. Possible causes??


Likely either:

1) Valve issue (like a burnt valve(s))
2) Valve lifter issue

Other more outwardly obvious issue may be a head gasket?

I believe only a "Leakdown" test can determine which of these issues it may be, but that is a complicated, multi-step process. Next, I recall reading that If the compression test is done with the throttle plate closed, cylinder #4 may always be the lowest (which I think is normal). You likely would need a qualified mechanic to test and repair. Good Luck!

Aug 29, 2013 | Cars & Trucks

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Low idle dies


It could be a vacuum leak or miss adjusted idle stop.
I need the year and engine size, Please.

Jul 22, 2013 | Chevrolet Blazer Cars & Trucks

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84 dodge 318 sluggish and laks power at throttle up whats wrong?


If adjusting the air valves on the carb doesn't help. you likely need to have the carburater cleaned. The air adjustment needles are located at the base of the carb at the front. Turn them out until you reach high idle, and then in again, about one full turn. If that doesn't help, you'll have to put a carb kit in, and have it cleaned.

Mar 03, 2013 | Dodge Cars & Trucks

1 Answer

1.9 L starts just fine but will not keep running at idle. Stalls when coming to a stop (automatic). Just changed oil, didn't help. If I hold the idler arm just a tiny bit, runs just fine. Please...


With carbureted cars, the idle speed was set by adjusting a small screw that held the throttle open just a little. That screw rested on a sort of a disc with graduated steps on it, the fast idle cam. When the choke was partially or fully closed, that disc was turned a bit to present a higher step for that throttle-adjusting screw to rest on, providing a higher idle speed during warm-up.

With fuel injection, there is no choke, and the throttle blade almost completely closes at all temperatures and states of warm-up. When the richer mixture is needed that a choke used to provide, the Electronic Control Unit (or Electronic Control Module) simply flows more fuel through the injectors.

There also is a short (incha and a half, maybe?) air passage that opens onto either side of the throttle blade, a bypass passage. There is an electrically controlled valve in this passage.

When the engine is cold, the ECU opens that valve a little more to produce a faster idle, as the "fast idle cam" used to. When the air conditioner is turned on, presenting a load to the engine, that valve is electronically opened just a little to keep the idle speed the same even with the higher load. If the car has an automatic, when it is put into gear, that valve is opened a little to keep the engine running with the additional load the torque converter applies to the engine.

All of these idle-speed adjustments make use of a tachometer function in the ECU.

Now. These bypass air passages can become blocked, and the electrically operated valve (it is adjusted through a motor turning) can get enough accumulated crud on it to prevent its operation.

I would recommend first locating that bypass passage and its valve, disassemble that and clean everything carefully. Reassemble and see if all is well.

If not, I would think the ECU or its wiring is where the problem lies. Naturally, look for the connector that might have fallen off the bypass control valve, and so on.

The fact that the engine runs would seem to argue that the tachometer function and the accompanying circuitry are working correctly.

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1 Answer

The first three speeds you get nothing....it only operates on high #4 speed and it is a little bit noisy


IF ITS AUTOMATIC TRANSMISSION. THROTTLE VALVE CABLE NEED ADJUSTMENT OR COULD BE THE GOVERNOR PROBLEMS LIKE VALVE STUCK GOVERNOR WEIGHTS BINDING. GOVERNOR DRIVEN GEAR DAMAGED OR.BURNED DIRECT CLUTCH PLATES.THE 1-2 3-4 SHIFT VALVES STUCK IN VALVE BODY. IF IT MANUAL TRANSMISSION SHIFT LINKAGE OR SHIFT FORK OUT OF ADJUSTMENT OR WORN DAMAGED OR I- 2- 3 GEARS AND BEARINGS WORN OUT.

Jul 09, 2010 | Cars & Trucks

2 Answers

On a 3.5 engine code reads low idle? any idea


LOW IDLE CAN BE CAUSED BY MANY THINGS.CLOGGED AIR FILTER. LOW COMPRESSION OR MISFIRE CONDITION.IDLE AIR INLET PASSAGE OR THROTTLE BORE IS DIRTY OR FULL OF DEPOSITS.IDLE AIR CONTROL VALVE FAILED.MASS AIR FLOW SENSOR COULD BE OUT OF CALIBRATION. THROTTLE PLATE THROTTLE SHAFT OR LINKAGE IS DAMAGED OR STICKING.PROBABLY HAVE REMOVE THROTTLE BODY ASSEMBLY REMOVE IDLE AIR CONTROL VALVE AND THROTTLE POSITION SENSOR.BUY CAN OF CARBURETOR OR THROTTLE BODY CLEANER SPRAY CLEAN ALL CARBON BUILT UP AROUND THROTTLE PLATES AND BORE.LET AIR DRY BUY A NEW THROTTLE BODY GASKET.

Jul 05, 2010 | Chevrolet Colorado Cars & Trucks

1 Answer

How do i adjust the idle? its running at 800rpm right now and dies if my foot is off the gas for too long


I don't think there is any adjustment for idle.
Sugestion:
Take idle control valve out and clean it with carb cleaner (you'll see black staff inside on turning door,you may spray a little bit of WD40 on the door after you clean it but blow it with compressed air after) also clean throttle body inside ,around flap and edges of the flap. Over the years , oil fumes create deposite of kind of gum substence which clogging up the idle valve and clearance between flap and throttle body , reducing amount of air coming through and bringing idle down.
For this job I usually take throttle body out , make sure to plug water hoses going to the T/B preventing coolant loss. Take extra care removing T/B , there is a gasket between T/B and intake manifold ,you'll have to reuse it , so try not to brake it as it will be stuck on either T/B or intake manifold or on both , use raisor blade to separate it on one side.

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2 Answers

Throttle sticks at times when starting out. Hear a popping sound and throttle moves easily then


there is a throttle-stop, this prevents the throttle valve getting stuck in the bore, put simply the valve is a perfet fit and if it fully closes it is liable to get stuck in that position, so a "stop" is employed to keep the throttle just a tiny bit open, but without increasing the idle speed, it is similar to an idle-control screw. tighten this a little, so it keeps the throttle a little more open - check this diagram to find the stop adjuster screw.09aa699.png

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1 Answer

Car will start but wont stay on


Idle adjustment. You didn't state the vehicle, so I will post two possible solutions.

Fuel injected engines typically have an IAC valve in the throttle body. This valve adjusts the throttle plate to be open to a certain extent. The computer can control this valve as need based on the density of oxygen in the air. Remove the throttle body and clean the IAC valve or replace it if necessary. Mechanical (gas engine) experience necessary.

Carb engines typically have an idle adjustment screw on the exterior that may need adjusted. Mechanical (gas engine) experience necessary.

Dec 30, 2008 | 1993 Chevrolet Suburban

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