sluggish acceleration when cold


roysleight
11-06-2008, 10:21 PM
My '93 Regal has developed an intermittent problem of having kind of a flat spot when accelerating only when first started. If I push harder on the throttle it will pick up but has a spot at low speed that it just doesn't want to respond. This doesn't happen all the time and once the engine has run for one or two minutes it runs fine. I'm guessing a sensor for fueling or ignition that responds to engine temperature. Any suggestions is greatly appreciated. I really don't want the dealer to charge me for a lot of parts while they try to figure it out. Thanks.

roysleight
11-10-2008, 10:45 PM
More info: Just happens when engine is cold and it hits the flat spot at about 2500 rpm. After running for a minute everything runs fine. Doesn't anybody have any ideas or similar experiences?

Scrapper
11-10-2008, 11:01 PM
whens the lastime you changed air and fuel filter,plugs,wires? try putting in some sea foam to. sounds like plug under power that does this and a wire can to. but sea foam will clean out your injectors.

good luck..

C man
11-11-2008, 01:21 AM
Or maybe it loses it voltage refrence signal on the throttle body at the position where the engine is at 2500rpm and it's only noticable when you first start because the computer compensates. For me most of my shifts are right at 2500rpm or below and you want reach that again until you get closse to 90mph if you're cruising.
...I could be wrong though

roysleight
11-13-2008, 10:01 PM
I change fuel and air filters regularly. Also recently replaced plugs and plug wires. Checked the TPS for flat spots with VOM and was fine. I will try some injector cleaner next time I get gas. I'll look for the Sea foam but I don't recall ever seeing that around here. Thanks for the suggestions.

Scrapper
11-13-2008, 11:06 PM
they got sea foam at most parts stores like a/d,a/z,rual king,even at walmart. they say lukas is good i disagree my nephew tryed in his bike and he said sea foam was better.he tried it in his truck lukas that is and his simi needless to say he went back to sea foam. but yah its anywhere for 5 something to almost 7 a can. they'll never convince me on lukas. some people say it's got water in it but hasen't tarnished up my carbs for the 3 years i been using it. i even put it in my oil before i change it on everything.

richtazz
11-14-2008, 04:46 PM
Check the IAC valve in the throttle body for carbon deposits. It could also be a sticky EGR, but check the IAC first and clean it and it's bore in the TB if it's carboned up.

roysleight
11-19-2008, 08:08 PM
Looks like it was the Mass Air Flow Sensor. I followed some advice from a mechanic that works at the dealership to pull out the MAF sensor and clean the tiny wire with some carb cleaner. The car is running fine now. A dirty MAF sensor will apparently make the engine run lean and now I notice that it idles better too. Hopr this will help someone else too. Thanks for all the help guys.

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