Bob's LS Story

They most certainly are under valued. That is why I got one. This is my economy car. Who could ask for more at this price point. If you are a fair mechanic you can afford one of these. If not you better have deep pockets. It takes a lot of knowledge to make these cars feesible on a budget and I have learned so much. Thank you all. Finishing up a 300 mile weekend and so far so good. CEL is still on but no miss. I am thinking I am going to dump a can of Seafoam in the tank that only has about 3 gallons in it. Run it about 10 miles and let it sit overnight. Drive another six miles toomorrow let it sit all day then three miles to Costco to fill her up tomorrow evening. What do you think? Too harsh?
 
Last night I put a can of Seafoam on about 4-1/2 gallons of gasoline. I have about 30 miles on it now. The thought I have is my #1 fuel injector is dirty or leaking. That is a possibility for the miss. Also I think I saw something on my scanner about the EGR. Is there any way that could affect a single cylinder? The thing I am noticing is I have the miss only on cold starts after sitting overnight. Runs great after that. That leads me away from a broken wire which would likely be more random. Also it doesn't just go away gradually as it warms. It is there till it's gone and it's gone when it's gone. For those reasons I suspect the pcm is OK as well.
 
No on the EGR. I don't really agree with the other theories either. Electrical problems can be sudden on/off and temperature dependent. (I'm not saying that it is the PCM or the wiring, just that I don't think you can eliminate them as suspects yet.)
 
I am far from deeming them good but my experience has shown much more random behavior in electrical glitches. This miss is behaving like clockwork so I am leaning mechanical. We will find it...
 
UBI: The LS is multi-fire at idle. At some RPM threshold, it switches to single fire. I don't know if temperature or other sensor data factors into the PCMs decision on when to multi-fire and when to single-fire.
 
That is interesting. Definitely deserves some consideration. Some extraneous factors around my #1 cylinder miss are...

1. That plug well was spotless clean for cylinder #1

2. The COPs were all matched but only #4 was marked as new. Generic no marking.

3. Had the same miss before I changed the coils.

4. Connector and wiring appear to be in good condition.

5. Transmission shifts weird/mildly harsh into 2nd and 3rd medium throttle only.
 
Bob,for what it's worth,I was working on my son's Taurus which had a dead miss on cyl. #4. I switched spark plugs,spark plug wires.....all were good.
Bent down,tried to hear the clicking of the injectors.......needed a stethoscope. The #4 injector had a loose connection,the clip being broken. I attached it firmly and he now has his 6 cylinders back.LOL! Just loose injector wires.
Thought I would mention it anyway. don-ohio :)^)
 
It's worth a look. I plan to spend a little time on it tomorrow morning. We will see what I find.
 
So this morning I go to check out any problem areas around the number one cylinder. Finding none visually I disconnect The number one fuel injector pigtail wiggle it around and reconnect it and of course the tab broke as well as the wire loom on the connector above it the second I touched it. I fired up the engine and of course the miss is there so I grabbed my scanner and am going to do some live testing and record the results while it is warming up and losing the miss. During this process while at a stop light I cycled the ignition off and on five times rhythmically and low and behold for the first time I had a no start situation at the intersection. I put on my four ways and ended up spending one light cycle troubleshooting the no start. I had no new codes just the cylinder miss and rich codes so I cycled the key a couple more times and nothing just not starting as if no fuel or spark. I decided to go wide-open throttle and ease out of it and see what happened and it actually started to attempt to start at about mid throttle so I let off the gas and attempted a normal restart to no avail. After a couple more normal restart attempts it finally just lit off as normal And I drove off noting it still had the miss at idle. When I got to my destination about a half-mile away the miss is dissipating and low and behold and there is a first generation Lincoln LS in the parking lot. Anyway my leading theories on the No start are possibly I broke a wire or connection when messing with it this morning. Possibly cycling the key five times triggered a security feature and disabled the ignition or fuel. Anyway I thought I would just type this post while waiting to meet the driver of the other LS I think I'm going to leave now and try to record the last live data on the way home as the miss is about gone now.
 
bobsquatch said:
... Possibly cycling the key five times triggered a security feature and disabled the ignition or fuel. ....
Click to expand...

Nope. The anti-theft feature(s) of the LS also disable the starter.

If the engine was still cold, it is possible that you flooded it with that trick (turning it off after a short run time).
 
Could have flooded it but when it did light off it ran normally without the brief stumbling/studdering you would expect. Who knows. Maybe the cam or crank sensor is failing. Miss is gone after warm up and it's running great...
 
So you have a miss and rich mixture codes? That's strange. If anything, misses cause lean mixture codes. (Why: If there is no combustion, no oxygen is consumed, so there is too much oxygen in the exhaust, which reads as lean mixture. It can't detect the raw gasoline.)
 
So it's running good now? So what do you think made it miss? Is your injector wiring dependable? don-ohio :)^)
 
Crazy thought...
Check the voltage on the positive terminal of coil #1 while it is running and missing.
 
I don't think it's missing every time when at speed, only at idle. So if it is missing intermittently or only burning a portion of the mixture it might show rich. Also, wouldn't the cat burn most of it up leaving some hydrocarbons for the sensor to read? Injector wiring seems dependable but not tested for sure. I will do a voltage test on coil positive tomorrow. Btw. Which is positive? I have a new job tomorrow so I am distracted. I will check in asap. Thanks again for your input.
 
No,like Joe said,a misfire makes it read lean because of the high amount of unburned air. don-ohio :)^)

bobsquatch said:
I don't think it's missing every time when at speed, only at idle. So if it is missing intermittently or only burning a portion of the mixture it might show rich. Also, wouldn't the cat burn most of it up leaving some hydrocarbons for the sensor to read? Injector wiring seems dependable but not tested for sure. I will do a voltage test on coil positive tomorrow. Btw. Which is positive? I have a new job tomorrow so I am distracted. I will check in asap. Thanks again for your input.
Click to expand...
 
My first thought was injector but it lasts too long for burning off leaky injector fuel puddles. I also ran a fairly concentrated dose of Seafoam through it so I doubt it's a partially clogged injector either. I am shying away from electrical connections because it's so predictable so... That leaves structural... Head gasket/head, valve train components, intake/exhaust manifold/gasket. Coil/Pcm... What am I missing? Pcm could be misidentifying the missing cylinder but the #1 plug was the only one fouling. After I test positive voltage at the coil I think my next move is to swap #1 and#4 injectors. What do you think?
 
The engine itself is actually pretty robust, so it's unlikely to be a hard failure. The wiring and the COPs, on the other hand, are NOT robust and are VERY prone to failure.

If you think it's a part failure, and #1 always shows failure, move the plug to a different cylinder, the COP to another cylinder, and the fuel injectior for #1 to yet another cylinder. If the problem moves, you know what broke because the failing cylinder should change. If it doesn't change, it's the wiring or the electrical plugs, which are known to fail.
 
don-ohio said:
No,like Joe said,a misfire makes it read lean because of the high amount of unburned air. don-ohio :)^)
Click to expand...

And the O2 sensors that read lean or rich are before the cats, so those two are not affected by what the cats do or don't burn. (The O2 monitors read that.)

If you move injectors around, you will need new o-ring seals for them.
 
I will order up some orings for the injectors before I swap anything around.

While I understand what Joe is saying. Completely unburned fuel/air charge has more oxygen in it to read lean on the upstream O2 sensor, it is counter intuitive. What else could cause a rich code?

So my car ran bad this morning. Standard cold miss an a stumble as I got on it to reach freeway speed. Did not clean up before I got to work. Still missing at idle in gear. It was very cold this morning. In the high 40's. Fired it up after work and purring like a kitten. 70+Degrees. I will check the codes after I get cleaned up.
 
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