Can something in the pcm cause 1 cylinder to run different than the others?
08-09-2010, 12:04 PM
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Can something in the pcm cause 1 cylinder to run different than the others? I'm asking this because I keep breaking the ringlands on my number 7 piston. Second time in 6 months. My mods are in my sig, total timing is at 28* not even coming close to knock. I'm out of ideas, but I know that the car acts up every now and again (idle surging and mis-firing) and I was thinking maybe the issue is in the pcm itself. Is this possible? I just want to find the cause of this because I'm about to put a forged 370 and I don't want the same thing to happen again.
Thanks in advance.
Thanks in advance.
08-09-2010, 01:23 PM
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Rear cylinders seem to be notorious for running lean.
Some may be due to how silt accumulates at the ends
of fuel rails, some from airflow bias in the intake. If I
were doing the plumbing I'd feed the rails from the rear
with a Y-block, and take the return off the front through
another Y and blow the pressure off there. That way the
rear cylinders are fattest and any silt tends to get swept
through and back to the tank / filter, not collect at the
dead ends.
Some may be due to how silt accumulates at the ends
of fuel rails, some from airflow bias in the intake. If I
were doing the plumbing I'd feed the rails from the rear
with a Y-block, and take the return off the front through
another Y and blow the pressure off there. That way the
rear cylinders are fattest and any silt tends to get swept
through and back to the tank / filter, not collect at the
dead ends.
08-09-2010, 06:22 PM
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So it's probably more fuel related than pcm. Thanks for the input, I'm going to have the injectors flow tested (42 lb'ers btw) and put the fattest ones out back.
Thanks.
Thanks.
08-11-2010, 07:55 AM
#5
Maybe take a look in the filter basket[s] w/ your plug reading lite. See if you can detect the "trash" that's perhaps collecting at the dead ends of the rails.
Sometimes, you can see it, some not.
IE: Last set of 160's I cleaned, had really BAD flow on 3 injs. I did nothing except remove the baskets, and flow went to dead-on.[Have seen this on several sets]. Looking at the baskets, they were originally red, but looked like mud. However, I could not see "hunks", only the discoloration.
Sometimes, you can see it, some not.
IE: Last set of 160's I cleaned, had really BAD flow on 3 injs. I did nothing except remove the baskets, and flow went to dead-on.[Have seen this on several sets]. Looking at the baskets, they were originally red, but looked like mud. However, I could not see "hunks", only the discoloration.