Question about 1988 Cadillac Sedan DeVille

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1988 de ville

Thank you for your help, I will check egr valve asap!! Would you know why my engine idles high?? I mean I can be at a stop light and take my foot of the brake and the car goes by itself, and it gets good speed like that???

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  • thomas thompson May 11, 2010

    check the air idle controler it maybe stuck or you have a vacuum leak



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If your EGR valve is stuck open its adding "false" air into the cylinders.  (just like a vacuum leak)  the engine will raise its idle speed to prevent the engine from stalling at idle.  the EGR should not be open at idle.  

Posted on Feb 01, 2009


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2 Answers

My car engine has start run for a few second with high throttle and then stop it, is this can cause by ecu failures?


I would check for vaccum leaks first - vaccum leaks cause RPM fluctuations.

I hope this helps

Oct 28, 2017 | Cars & Trucks

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How do I correct high idle problem

Year/make/model??? Applying vacuum to the EGR and making the valve open will not be the correction. Once opened, this valve allows unburned exhaust gas back into the combustion chamber resulting in a rich mixture. The computer sees this rich mixture and reduces the injector pulse allowing the idle to slightly lower. If the vehicle were at proper idle speed and this valve is opened, it would run rough snd possibly stall

Jan 20, 2016 | Cars & Trucks

1 Answer

Diagnose 1988 ford e150 fault codes 12, 21, 34, 44, 13, Engine overheating, throttle high on idle, and while driving

Based on the codes you gave the high idle is because of the EGR valve. (12,13 and 34)
21 is a temp sensor code, and I don't have a 44 listed. I hope this helps.

Feb 23, 2011 | Ford E-150 Cars & Trucks

1 Answer

Code 15 ignation output car runs good when cold gets warm check eng light miss.lacks power not hitting on all cyl. suspect bad ignitor..

Check the EGR valve. Look up on the internet where on your car it is located. Find the vacuum line connected to it. Start the engine cold and as it warms up and starts to miss and stumble, pull off the vacuum line from the EGR. If the car idles fine, replace the EGR. Ignition system problems are more likely to occur at idle or lower rpm. Besides, testing the EGR is free, easy and do fail in high mileage vehicles.

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3 Answers

Will a faulty E.G.R.valve on a 1988 Olds.Cut.Sup.FWD cause a hot engine to stall when stopping at corners?

well it will casue it to stall if the egr is stuck open and you stop at a light or stop sign,due to it beinge stuck open the open egr valve acts like a vacum leak,,,,ive also seen bad fuel pumps and fule filter to cause a stall while hot and cornering

Oct 07, 2009 | 1988 Oldsmobile Cutlass Supreme

1 Answer

I have a 1999 Buick Lesabre Custom and in the last few days the engine revs higher than it should while stopped or parked. I also notied that it is a little harder to stop while driving. I took it to a...

You could have one of three problems or The idle control valve could be bad or you have a digital EGR valve not closing Gm has two EGR valves one Mechanical and one electric so without knowing the size of the engine I can't help you much more, except that you may pull the EGR valves off and clean the pintal's off, and lube the pintal shaft with graphite dust, for the mechanical one you would have to **** on the tip of the vacuum hose and see if the pintal valve does not move then the egr valve is bad, if you look at the pintal valve and there is a gap then it has carbon buildup on it. And you year of engine can have as many as three different egr VALVE COMBANATIONS. So let me know the size and I will try to help you more, the EGR valve is located on the exhaust manifold. If it has a digital stepper EGR Valve you will have to see if the pintal valve is closed, when you remove it the engine cold it should be closed if it is not then it has carbon in it or the stepper motor mat be defective. Use berrymans Carburetor Cleaner spray type it cleans the best and buy a wire pipe cleaner brush made out of brass to clean with. You can get at a Wal mart store or any gun shop store but a little more expensive. If this helped please rate this free question and thank you for using Fix-ya.

Aug 20, 2009 | Buick LeSabre Cars & Trucks

2 Answers

1988 Ford Ranger Super 2.9L V6 Hesitating and Stalling out

Check EGR valve this controls idle speed it might have carbon build up hold the valve open. All so check fuel pressure.

Jun 26, 2009 | 1988 Ford Ranger

1 Answer

1988 Jeep Cherokee

Please check the EGR valve, located on driver's side of engine below intake manifold. Inside of the EGR valve is a diaphram pushed out by a spring. The spring rusts away, leaving the diaphram in the wrong position for idling. I have stretched out the spring, or just replaced the valve and had good luck thereafter. Valve is round about the size of a pop can (diameter) and shaped like a UFO.

Oct 23, 2008 | 1988 Jeep Cherokee

1 Answer

Timing help

Have you tried to replace the IAC (idle air control) valve?

Another probable cause could be a stuck EGR solenoid. If this solenoid sticks open, it will send vaccuum to the EGR valve, which will open the EGR valve and flood the system with too much air and "snuff" the engine out. This problem only shows up at idle. The engine should run fine when driving. Please let me know if this helps.

Jul 06, 2008 | 1988 Chevrolet C1500

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