Impala LS 3.8 loping at idle since backfire
#1
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This POS is hard to start sometimes. It backfires (actually a heavy HUFF thru the intake) and dies on the 1st try at medium warmup. It did it over the weekend and now it lopes ( gallops) at idle both in gear or out. Out of gear it will get so low as to knock slightly when it tries to kick the idle up to compensate. It was a heavier than usual HUFF this time. Any ideas what blew up or off? It runs fine at speed at least I don't notice anything.
This car has been a real pain in the azz. The tranny went out at less than 50k and left my mother stranded on the freeway (it was her car until she passed). I had to replace an axle, the front wheel bearings are going out so ABS and TRAC is always on and it stutters on turns. The radiator just cracked a can, there is an electrical gremlin in the dash that doesn't let the radio, cruise and overhead panel come on unless I rattle the fan speed switch back and forth. There are squeaks and rattles in the dash as well.
This was a top of the line Impala purchased new and taken care of.
Anyway...any help on the stutter, loping, galloping thing?
There is no engine light on.
Thx
JohnF
Phoenix
This car has been a real pain in the azz. The tranny went out at less than 50k and left my mother stranded on the freeway (it was her car until she passed). I had to replace an axle, the front wheel bearings are going out so ABS and TRAC is always on and it stutters on turns. The radiator just cracked a can, there is an electrical gremlin in the dash that doesn't let the radio, cruise and overhead panel come on unless I rattle the fan speed switch back and forth. There are squeaks and rattles in the dash as well.
This was a top of the line Impala purchased new and taken care of.
Anyway...any help on the stutter, loping, galloping thing?
There is no engine light on.
Thx
JohnF
Phoenix
Last edited by johnfl; November 7th, 2011 at 1:32 PM. Reason: left out info
#2
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OK, it finally threw a code after 2 days. P0171. According to what I read online these engines are prone to intake manifold gasket problems so I was expecting the worst. I was lucky, it had split and blown off the large vacuum line on the forward side of the throttle body. The one that has 2 smaller lines out the end, one goes to the fuel pressure regulator and the other to something else..I didn't pay any attention to where the other line went.
Runs fine now.
JohnF
Runs fine now.
JohnF
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