Engine surging at cruising speed
08-08-2007, 11:39 PM
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Engine surging at cruising speed My 95auto z28 was runnin fine for a little while after my new header install...... but now problems are startin up again. The car has a really rough idle, not just shaking but the rpms continually move from around 650-950 rpm. Once u give it a little gas to bring above 1,000 it calms down. The main thing i notice though is that when im cruisin around 45-70 mph the rpms will suddenly drop a grand and the engine seems like its choking out on me. When i push the gas in smoothly nothing happens until the throttle opens about another quarter then the rpms suddenly jump up a grand and the car seems like its runnin fine. I really noticed it tonight at the track. Before the headers, 52mm, bypass, bored MAF, new optispark, plugs, and wires i ran a 14.06..... I ran a best of a 14.1 tonight (also running a 14.5 and a 14.7 which i had an even better launch) my 60' is about a 2.06. My friend tells me im breaking up top end cuz he could hear it and every time it does, smoke blows out the pipes. ..................
Checked for burned wires or plugs and found nothing. Replaced the TPS and it just keeps gettin worse. I had a Jet Stage II chip on and tried disconnecting the battery and removin the chip. Didnt see any differnce in the way it drives. So im currently at a stand still. The car runs but it runs like ****....... Any suggestions???????????
Checked for burned wires or plugs and found nothing. Replaced the TPS and it just keeps gettin worse. I had a Jet Stage II chip on and tried disconnecting the battery and removin the chip. Didnt see any differnce in the way it drives. So im currently at a stand still. The car runs but it runs like ****....... Any suggestions???????????
08-09-2007, 04:02 PM
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Could this be a problem with deleting the AIR and EGR without tuning the car? I checked the O2 sensors when i did the header swap and they weren't black or anything and appeared to be fairly clean. Some one also told me it may be the MAF sensor going bad. Is there anyway to test for these things?
And another thing.... what does it mean when your car is in open/closed loop???
And another thing.... what does it mean when your car is in open/closed loop???
08-09-2007, 06:18 PM
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Come on guys.... someone out there has to have some suggestions. If i cant find out whats wrong im probably going to get a tune from madz28.com and i dont wanna waist the money if its not gunna help. -thanks
08-10-2007, 06:56 AM
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open loop is when the car runs on its preset setting in the computer (air/fuel, timing) and closed is when it starts reading data from the O2's and adjusting its air/fuel accordingly. there are other things but thats the most of it
