What now? STILL running rough

MERCURY SABLE
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GOODHEART99362
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91 mercury sable/125k/3.8l--after complete tune up still rough, 3 scans gave me diff. things which i replaced--o2 sensors, heat temp sensor, etc. checked 4 vacuum leaks, cleaned egr valve, cylinders are EVEN. changed filters, wires, plugs, pc valve. ran fuel cleaner thru gas at least 3 times now. engine light comes on only sometimes but goes out after about 10 sec.I suspect one thing--bad spark plug wires, which would very much upset me-supposed to be lifetime and after all this money and work it turns out THIS? what else COULD it be? tired of getting ripped off and the results from it--see how it snowballed?
Apr 12, 2007 at 3:16 PM
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MERLIN2021
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On 91's it's usually the manifold absolut pressure sensor...MAP!
Apr 15, 2007 at 8:37 AM
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GOODHEART99362
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[quote:853508d7fd="merlin2021"]On 91's it's usually the manifold absolut pressure sensor...MAP![/quote:853508d7fd]
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After reading some of the answers I thought of that, but why didn't that show up on the scans? I don't want to by another part and have the same problem. How can I test for it? It's easier to test the wires--simple things first. I have a manual but it's basically the same thing: "it could be this or this or this". I work on cars myself and maybe that's why they are taking advantage of me (female). Also want to share info for huge savings on parts: PartsAmerica.com. You look up your part and they send you to a local affiliate, where you get up to or even more than a 50% discount. The site tells you if it's in stock, and the "affiliate" can't jerk you around. Only on a special order--like a custom/import part--can they charge you a regular price. Well thanx for the suggestion. Maybe I'm getting somewhere. Why the fuk did they put computers in cars?
Apr 16, 2007 at 1:35 PM
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MERLIN2021
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Yes if you have a code reader it may give you a fault code for the MAP The other thing you can check for is vacuum leaks, get a can of spray gumout, spray around vacuum hoses and intake manifold, see if the engine changes speed. if it does you've found a leak...
Apr 17, 2007 at 3:57 AM
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GOODHEART99362
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[quote:e928d04c7e="merlin2021"]Yes if you have a code reader it may give you a fault code for the MAP The other thing you can check for is vacuum leaks, get a can of spray gumout, spray around vacuum hoses and intake manifold, see if the engine changes speed. if it does you've found a leak...[/quote:e928d04c7e]
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I had checked for vacuum leaks but will try the gumout thing. Don't have a code reader--have enuf useless tools! A MAp sensor will cost me about $100-even at a discount price (PartsAmerica) so thanx for the tip. Will keep you updated until I find the problem. This should be a really good engine when I'm done! My last old beater won 2nd in a Demo Derby-it had a V-6 in it too. P.S. Cool name..that was my uncle's name too, only spelled Merlyn. (German)
Apr 17, 2007 at 1:42 PM
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