Wtf is going on with this
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Staging Lane
Joined: Dec 2021
Posts: 64
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Wtf is going on with this What is going on with this? New to hptuners and just finished putting an lq9 into my 97 chevy obs. No codes, no miss fires, injector pulse starts at 5.3ms and then bank 1 rises to 7.9 while bank 2 stays the same. Wouldn't a vacuum leak affect both banks? I unplugged the maf and the idle changed for like half of a second but continued to run rough. Put into gear it runs even rougher and shakes the truck and its got no power when I try to drive it, like it would if it were starting in 3rd or something. Any suggestions
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
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bank 2 o2 sensor begins at 287 and climbs to 900 and slowly drops back down to 3 something and fluctuates from 3 something to 700 or so and bank 1 o2 hovers around 370 and drops down to 100s and fluctuates there. There aren't any exhaust leaks on either side, the only thing I can think of is the injectors being clogged since last time I messed with them at least 2 of them were completely dead. Also would a bad maf cause this? Or an intake gasket? Or would that affect both sides?
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Odds are that a dead miss on bank 1 is sending unburned air out the exhaust, and the trims keep dumping more fuel to try to correct the o2 sensor lean reading that all the unburned air causes. Pull your plugs and see if 1 looks clean and the others are almost fouled out on bank 1.
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Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Odds are that a dead miss on bank 1 is sending unburned air out the exhaust, and the trims keep dumping more fuel to try to correct the o2 sensor lean reading that all the unburned air causes. Pull your plugs and see if 1 looks clean and the others are almost fouled out on bank 1.
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Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Odds are that a dead miss on bank 1 is sending unburned air out the exhaust, and the trims keep dumping more fuel to try to correct the o2 sensor lean reading that all the unburned air causes. Pull your plugs and see if 1 looks clean and the others are almost fouled out on bank 1.
If you are maxing out trims on bank 1 and the plugs are clean, there are 2 options. Either you have no spark, or you have no fuel to the entire bank. Are you sure you don't have the bank 1 coil packs backwards from front to back?
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
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yes I verified that and injectors are all where they should be
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Staging Lane
Joined: Dec 2021
Posts: 64
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well, they may be hooked up right but you were right None of the coils on bank 1 are firing. I wonder why though
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Staging Lane
Joined: Dec 2021
Posts: 64
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I just checked grounds and they are connected unless its just not a good ground. I have each bank grounded to the cylinder head they're bolted to. I wonder if I need to add another battery ground to that head because I just realized there is no ground there besides the pcm ground at the back of the head.
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Thread Starter
Staging Lane
Joined: Dec 2021
Posts: 64
Likes: 2
Just figured it out. Theres a broken wire somewhere between the main connector on the coil harness to the coils themselves. I got it running good for a second and then went out and saw my spark plug test light flashing and plugged everything back in and decided to jiggle the wires and the problem started again. So I scanned it, got a misfire for coil 7. Started the truck again and moved the harness around and it started running good again, checked the short term fuel trim, looked good and got in to back it up and move it forward to see what would happen and spun the tires haha **** yes then I thought ok gotta find out why so I kept moving the harness trying to locate which side of the harness it's on and sure thing it is the harness behind the coils. Now where to buy a harness for the coils, im done messing with this thing haha