Is my ECU bad? Fuel filter? Grounds?

[sjrobinson]

97 Accord Ex, 2.2L VTEC (F22B1) Manual 5 Speed 4dr sedan
I’ve posted with questions surrounding this before but heres more

So I think my problem is electrical as ive gone through everything else. I see that my radiator should be grounded but its not. I’m going to address that but I’m not sure if that could cause these problems.

Issues are: intermittent strength of throttle response and torque, fluctuating idle heard in exhaust, delayed idle when put into neutral (1000 rpm for a second, then drops to 700-750), occasional “misfire” at high consistent speed. No CELs. 1297, 0171, and 0170 were all fixed after changing o2 sensor and reinforcing main ground.

Mind you here are my mods
421 mid-high end torque open header
2.5″ performance exhaust with stock cat
f23 intake manifold swap
Cold air intake
throttle body spacer

I’ve checked for exhaust and vacuum leaks and there are none to be found. The battery and cables have been changed. Another suspicion is still the fuel filter.

All the mods are bolt ons but ive experimented with my car so the electrical may have some issues I cant find.

I just ran some tests. Heres what I get. You can see where I turn everything on. Here are the values recorded during an idle. I’m just looking for ideas of where to look, what pops out as unusual to anyone reading them.

I revved the engine a little at first, then idle, then turned on high beams, a/c, radio, hazards and rear defroster. Then I let it idle. I can tell when the car is acting especially funny cuz the exhaust will rattle against the heat shield meaning that the engine behavior has changed. On a good day, or trip really, theres no exhaust rattle and a nice sound deep and smooth sound coming from it. Towards the end where the rpms go to 699 is when the rattling really starts. Its not a loose rattling, its a shaking exhaust muffler rattling. Hope you guys can make sense of these readings. Let me know if you need more.

Sorry the seconds and data are kinda close, thats how it copied. Seconds are always on the left. Then space before the readings. All data is in closed loop mode.

Battery
Time(seconds) Volts
5.997282 14.1
11.428214 14.1
16.470890 14.1
21.675770 14.1
26.750520 14.1
31.975686 14.1
37.231145 14.1
42.683460 14.1
47.652967 14.1
52.442358 14.1
56.877603 14.1
61.022916 14.1
64.851678 14.1
68.306096 14.1
72.225936 14.1
75.672856 14.1
79.066324 12.7 <---Turned on all electrical components 82.332788 12.8 85.771717 12.9 89.170983 12.6 92.516202 12.5 95.882672 12.4 99.361067 13.9 <---Turned off all electrical components 102.759472 14.1 106.132946 14.1 109.533715 14.1 112.908612 14.1 116.322677 14.1 119.613610 14.1 123.005277 14.1 126.459216 14.1 129.832741 14.1 133.203385 14.1 At the same time here are my rpms (I revved the engine a lil at 18 seconds) Time(seconds) rpm 2.448508 697 8.215018 696 13.421576 764 18.532101 1630 23.703783 680 28.828844 682 34.109839 702 39.352358 704 44.699753 697 49.388105 704 54.149016 691 58.550535 701 62.758271 682 66.608184 708 69.962330 701 74.030712 703 77.399529 709 80.738376 742 84.153800 759 87.509380 776 90.875482 779 94.243496 781 97.670850 777 101.107722 768 104.446242 752 107.913459 695 111.282016 694 114.594193 677 118.037183 703 121.394458 694 124.778205 699 <---Muffler starts to rattle constantly 128.167646 693 131.532149 699 134.982052 699 Timing advance: Time(seconds) relative to #1 cylinder 3.234721 15 8.929452 14 14.084521 34 19.214055 33 24.352838 16 29.490086 15 34.774836 14 40.318197 14 45.298622 15 50.017272 14 54.475131 14 58.882236 14 63.082280 14 66.935437 14 70.941517 14 74.364036 14 77.729949 14 81.045255 14 84.477693 15 87.840576 13 91.207251 14 94.568271 13 98.000712 14 101.431957 11 104.777388 13 108.221201 15 111.605548 14 114.927559 14 118.359934 14 121.698636 15 125.112817 14 128.496122 14 131.870760 14 135.307788 14 Upstream sensor voltages Time(seconds) Volts, % 4.799804 0.155, -5.47 10.326264 0.835, -7.03 15.404645 0.135, 7.81 20.558779 0.955, 8.59 25.658182 0.935, -7.03 30.830250 0.195, -8.59 36.099494 0.875, -7.03 41.608622 0.585, -3.91 46.575056 0.680, -8.59 51.301157 0.780, -3.91 55.756079 0.740, -7.81 59.874365 0.250, -4.69 63.729599 0.820, -7.03 67.591670 0.175, -5.47 71.604762 0.875, -7.03 75.002044 0.155, -6.25 78.394162 0.895, -5.47 81.684476 0.155, -5.47 85.134137 0.505, -2.34 88.499887 0.195, -1.56 91.870322 0.820, -2.34 95.191731 0.800, -2.34 98.661432 0.780, -2.34 102.065373 0.895, -2.34 105.437516 0.955, -2.34 108.860197 0.935, -5.47 112.267641 0.895, -8.59 115.621818 0.230, -7.81 119.001287 0.740, -6.25 122.360124 0.410, -7.81 125.764457 0.895, -5.47 129.139503 0.800, -8.59 132.513555 0.390, -6.25 Percent Load Time(seconds) % Percent 0.440799 24.31 6.461805 23.53 11.798366 23.53 16.914282 27.84 22.064195 23.53 27.168049 23.14 32.420472 23.53 37.699677 23.53 43.055334 23.53 48.071659 24.31 52.805476 24.31 57.294306 24.31 61.437388 24.31 65.295293 24.31 68.673149 23.53 72.674735 23.53 76.070201 23.53 79.439250 32.16 82.806106 34.12 86.185793 35.69 89.545481 34.90 92.939987 34.90 96.326358 33.73 99.810194 32.16 103.175070 24.31 106.555616 23.53 109.933148 24.31 113.298296 24.31 116.732403 23.53 120.060446 24.31 123.424182 24.31 126.834206 23.53 130.308993 25.10 133.681524 24.31 and absolute manifold pressure Time(seconds) kPa 2.039279 24.0 (Absolute) 7.882281 24.0 (Absolute) 13.091476 24.0 (Absolute) 18.201645 30.0 (Absolute) 23.357996 24.0 (Absolute) 28.530283 25.0 (Absolute) 33.775267 25.0 (Absolute) 39.022407 25.0 (Absolute) 44.375607 25.0 (Absolute) 49.054661 24.0 (Absolute) 53.798419 24.0 (Absolute) 58.242169 24.0 (Absolute) 62.424291 25.0 (Absolute) 66.281258 24.0 (Absolute) 69.632951 25.0 (Absolute) 73.698709 25.0 (Absolute) 77.067580 24.0 (Absolute) 80.406224 37.0 (Absolute) 83.830033 37.0 (Absolute) 87.178772 37.0 (Absolute) 90.542626 35.0 (Absolute) 93.911201 34.0 (Absolute) 97.339888 34.0 (Absolute) 100.782064 34.0 (Absolute) 104.113873 24.0 (Absolute) 107.581799 24.0 (Absolute) 110.947386 24.0 (Absolute) 114.265784 24.0 (Absolute) 117.704282 24.0 (Absolute) 121.064243 24.0 (Absolute) 124.446635 25.0 (Absolute) 127.844372 25.0 (Absolute) 131.216302 24.0 (Absolute) 134.653875 24.0 (Absolute)

Topic

[EricTheCarGuy]

When confronted with performance problems it’s important not to make assumptions or get too complicated. I’ll also say that any alterations you’ve made to the engine are suspect so be sure to verify their operation as well. Here are some videos that I hope will give you a good guide to start with. Note that an ECU problem is NOT likely so put that at the bottom of the list of suspects until you’re able to gather more evidence.

Solving Performance Problems 1

Solving Performance Problems 2

Re Performance Problems

[sjrobinson]

Thanks for the videos. It turned out a $20 grounding kit solved almost all the problems. My throttle response is 10x better and the overall performance and fuel consumption is great.

[college man]

thanks for the update.

[EricTheCarGuy]

Thanks for the update and for using the ETCG forum.

[Author]

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