Okay, so I've been dealing with this issue for a while now. I ran out of time 2 months ago, and unfortunately got an overdue inspection ticket. Let me start from the beginning, I bought this 1994 firehawk with the intention of fixing it. The whole exhaust system was shot on it as well. Anyways, when I finally got the money, I replaced the manifolds with a blown driver side gasket only where the number seven cylinder is with shorties paceshitter headers. The car continued to run rich and backfire. I figured it needed to tune, but it never got better. Sometimes it won't backfire at all and sometimes it does it like hell. My computer tells me that the long term is maxed out on bank two at 160. I took it to the DMV for the hell of it just to get the inspection fail letter and the hydrocarbon ppm is 8600 and carbon monoxide percentage is at 3.45 at idle and high idle. Those numbers are suppose to be way lower. My friend, being the genius that he is, knew that there was something wrong with the number seven injector because the gasket was blown in that location only. I got a used injector from someone who parted out a firebird for cheap just to test his theory. When we pulled the rail on the driver side, sure enough, there was no o-ring on the number seven injector. Also, the connector for the one and three was swapped. I don't even know how I drove this car around for so long without realizing that. We swapped the injector with the one with cheap one, but it really didn't improve anything. So far, we have done the plugs and wires. There is a new MSD ignition coil. If it helps at all, backfiring mainly occurs while cruising. For example, it will backfiring like hell at constant 1500-1600 rpm; it starts to clear up if I give more gas. This problem is obviously the car getting too much gas; you can smell it when it backfires. If you drive the car too long, your eyes start to burn from the fuel. My question is can a bad distributor, the infamous optispark cause one side to run crazy rich? Keep in mind, it can spin up to 5800 no sweat. My understanding has it that the optical part allows it to go up to high rpm and the cap and rotor part controls the timing essentially. Is it possible that just the cap and rotor is bad? You can tell it is definitely the driver side because all the paint blew off the header in a few days. The paint on the passenger side is still there almost 2 months later. Any questions that will help or suggestions are appreciated.
94Firehawk045
i doubt it's the opti.
could be a bigass exhaust leak, an injector problem (stuck open, injector ctrl wire shorted to ground, etc), or some odd vacuum leak.
also in a sequential system like this, if one cylinder fails to fire, that cylinder will be pumping pure oxygen and be reading LEAN, causing the other cylinders on that bank to run RICH. so if, for example you have a spark plug wire that's burned or totally failed, it can cause behavior like that.
a good first step might be to run it in open loop (unplug your o2 sensors or whatever) see if it still runs rich to rule out a bad or miswired o2 sensor or exhaust leak.
could be a bigass exhaust leak, an injector problem (stuck open, injector ctrl wire shorted to ground, etc), or some odd vacuum leak.
also in a sequential system like this, if one cylinder fails to fire, that cylinder will be pumping pure oxygen and be reading LEAN, causing the other cylinders on that bank to run RICH. so if, for example you have a spark plug wire that's burned or totally failed, it can cause behavior like that.
a good first step might be to run it in open loop (unplug your o2 sensors or whatever) see if it still runs rich to rule out a bad or miswired o2 sensor or exhaust leak.
missed that part.. that's totally incorrect.
the optical part provides a timing reference (so the computer knows what position the camshaft is in). this reference consists of a high resolution signal (for fine grained position) and a low resolution signal (basically tells it what cylinder it should be firing on)
the cap and rotor controls nothing, it merely distributes spark from the coil to the individual plug wires
it's the computer that controls WHEN the spark happens, and it does this based on input from the optical sensor in the opti (which consists of two signals) as well as fine tuning from some control signals from things like the coolant temp sensor and MAP sensor.
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