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Discussion Starter #1 (Edited)
I've been trying to figure this out myself for about a week before asking.

sysmptoms: My engine misses, worst at full throttle. It will miss sporadicaly at idle, and misses most often when going over bumps/ rattling (which sucks offroad). Checked for any loose connectors, found none, tried tapping/twisting injectors and other electrical components, no change. Checked timing and valve lash, both perfect (valves set to a tight .7 intake .11 exhaust). Tried a different (junkyard) coil, no change. Code said TPS, put in a good junkyard TPS from an 85 celica (before it was worse with the TPS connected , now its same either way). Check engine light will flash on while missing during driving, but no codes. Seldom the charge/brake lights will flash on when missing. Has missed so bad it died on highway. EGR works, makes no difference if driven with vac. hose disconnected from EGR valve.

Also I have to give it about a 1/4 throttle to start, makes me suspect a vacuum leak/AFM? I will ohm test AFM, though I doubt its bad.

Conditions: I have no fuel pressure VSV, just a vacuum line from intake housing to fuel pressure regulator. Exhaust is disconnected in front of cat. (insufficient backpressure?). Cheap remanufactured motor recently dropped in.

Possibilities: I still suspect fuel pump (since worst under load and at full throttle when it'd need more gas), distributor/wires/plugs (but they're still pretty new), vacuum leak a strong suspicion. I tried spraying starting fluid/WD-40 all around vacuum lines, no change. ECU also suspect. I will pull and ohm test it.

Anyone?? please.?..
 

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pull off 1 wire at a time while engine is running. good running cyl. will make it run worse. pull them untill u find 1 that doesnt change the idle. that is ur bad cyl. go from there. check that plug, or wire, or compression, dist cap? basic narorrow it down:p
 

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Discussion Starter #4
it isn't consistent to tell by pulling plugs. It really only usually happens at full throttle or going over bumps/rattling. I'll re-check wires and plugs anyway. Is there a way to check fuel pump?
 

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Discussion Starter #6
loose ground caused miss

While disconnecting the entire engine wiring, I found a loos ground.
 
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