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Missfire under hard acceleration. Please hellp!!!!

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Old 04-23-2006, 08:55 AM
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Default Missfire under hard acceleration. Please hellp!!!!

I did a cam swap and valve springs, push rods, timing chain ect. in March. Car was running fine. Ran about 3 tanks of gas. The other day it sounded like I blew up the motor. It backfired and shut off at around 4000 RPMs Started back up and drove ok untill I hamer down and it backfires and sputters and shuts off sometimes. I have no SES lights. So I am assuming it is a misfire. I checked all the plug wires, valve terain, 4 of the spark plugs, (they were just changed 1000 milse ago). Every thing looks ok. Could I have a bad coil pack or fuel injecter? If so shouldnt I get a SES light? How do you check a coil pack or fuel injector? What the hell is wrong with this car? Please help.

Car has SLP headers and y pipe, MAF, lid, and custom tune by Texas speed. Cam is 228,228 on 112LSA. Cheap Flowmaster exhaust. I aslo get codes for the front 02 sensors the rears are deleted. Thanks for all the input so far. Do mass air flow sensors go bad? Is there a way to test them??

Well I got new 02 sensers. Took a ride with the snap on scanner. No missfires at all. MAF seems to be working fine. No other codes? What the hell is wrong with this thing???? Somebodys got to know???

Take the 2 seconds and disconnect the MAF. Those bitches get dirty and do the same thing you are describing. When mine acted up I was going nuts trying to figure it out.

Easy to check. Disconnect and go for a ride.

I had it disconected and it had a hard time idleing and finaly got to the point where it would idle and I did not even get around the block and seemed to be doing the exact same thing. Should I drive it farther with it disconected?
Old 04-23-2006, 08:59 AM
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Sounds like it's in the tune. Did you go there and have it tunned, or mail order a tune?
Old 04-23-2006, 10:32 AM
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Mail order custom tune from Texas speed. It has been runing fine before.
Old 04-23-2006, 02:20 PM
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bent pushrods,cracked, broken or weak valve springs
Old 04-26-2006, 08:40 AM
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Headers melted crank sensor wires. Fixed.




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