Through a long strange series of events, I just purchased a 2003 Lincoln Town Car Executive. The car has some minor issues, nothing out of the normal though. About a week ago, the car died several times when idling or at a red light. so, I cleaned the MAP sensor and used Amsoil power foam to clean the throttle bottle. For about a week the car has run well except today it started acting up again. The engine began acting like it wanted to die/ran rough at idle.

So this morning, I added a half bottle of Gum-Out to the fuel when I filled the car up with 87 octane gas. I'm wondering if I should switch to ethanol free gasoline?? Or, could there be water in the gas??


BTW, I purchased this car so I could get down to business and finally fix the 1984 300D correctly which will take some time. Having the Lincoln will allow me to repair the 300D correctly which is priceless in my opinion.

Sounds like a bad or sticking idle air control.

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Satan creates nothing: he only ruins everything. He does not invent: he tampers. And his followers are no different ~ Archbishop Carlo Maria Vigaṇ

Interesting, a bad or stuck Idle Air Control Valve is what I was thinking as well. I've seen people pull them from wrecking yards for five dollars or purchase new for around a hundred dollars.

Try removing and cleaning it first.

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Jim

will do. when this problem first started, I used a MAP sensor cleaner to clean the MAP sensor. I then used Amsoil Power Foam to clean the throttle body although the amsoil power foam can was probably over 20 years old so the can did not fully empty.

After those two cleanings, the engine definitely ran better then after about a week the car began gagging at idle. I then threw in a half a bottle of Gum-Out into the gasoline when I filled up.

I am still considering switching to ethanol free gasoline though. I will try cleaning the Idle Air Control Valve as you suggested.

It is a nice car although there are some engineering features on mercedes that are still superior to any domestic car. I'm merely using the car to travel about while I have time to work on the 1984 merc 300D and chase parts.

Certainly sounds like an IACV. Clean it out and see how it goes -- Id also be looking for vacuum leaks (cracked hoses or seals) on the intake side. Throw a scanner on it and observe fuel trims at idle.

I wouldnt worry about switching from E10 to EF, I doubt you will notice any difference but also won't hurt anything.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

I had an '86 Town Car that had the same problem. Cleaning the Idle Air Control fixed it. Half an hour of my time and a can of whatever I cleaned it with.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

thank you for the advice, I will try cleaning the idle control valve. the scanner idea is a good one, any particular brand/model scanner you recommend?

There are a lot of OBD2 scanners that go through bluetooth or wifi. Pair that with torque app. Those apps allow you to view and log data as it comes in. You will want to observe fuel trims and upstream O2 sensor values.

For vac leaks, the old school way is to spray some starter fluid or carb cleaner (or propane from an unlit torch) around the engine bay and see if it stumbles.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth