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new engine troubles...

  • Thread starter Thread starter 1991vert
  • Start date Start date Oct 7, 2006

1991vert

10 Year Member
Feb 27, 2004
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7
69
Ludlow, MA
Oct 7, 2006
#1
  • Oct 7, 2006
  • #1
well i finally got the engine running and the car drives around. it's not running how it should though. for a 347 it seems to have crap for torque down low. the other night i had trouble spinning the tires in the rain on DR's!

i noticed when setting the timing before the timing light would cut out so i set it to 10 real quick and tightened it down. well the car ran like butthole. i replaced the coil and it seemed to be a little bit better and i went to check the timing again. i pulled the spout and the timing was at like 30*! so i set it back down to 10-11, but once again the timing was jumpy. it was A LOT less jumpy this time though and the light didn't cut out, but when looking at the pointer it would jump from 10* to 20* everyone once in a while and then back to 10*.

here's what i've done so far to trouble shoot:

pulled the codes and i got code 81 from KOER and code 91 from KOEO.

81 - inlet air control circuit malfuction. <- controls air at idle

91 - bank2 oxygen sensor lean. <- probably just needs replacing.

i replaced the coil which helped it out a little.

i checked the rotor/cap and the cap had corrosion on it so i took a wirebrush to it and i also did the same to the tip of the rotor.

does anyone have a clue?
 

1991vert

10 Year Member
Feb 27, 2004
1,103
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Ludlow, MA
Oct 7, 2006
#2
  • Oct 7, 2006
  • #2
bump
 

bob331T76

New Member
Aug 28, 2005
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so cal
Oct 7, 2006
#3
  • Oct 7, 2006
  • #3
have you had it tuned yet, my 331 ran like dog poo until i got it tuned , picked up 67rwhp too!!
 

jrichker

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Oct 7, 2006
#4
  • Oct 7, 2006
  • #4
Code 91 can be a vacuum leak or bad O2 sensor.
 

Grn92LX

Fidanza Man!
Founding Member
Jan 14, 2001
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Oct 7, 2006
#5
  • Oct 7, 2006
  • #5
Vacuum leak!!
 

1991vert

10 Year Member
Feb 27, 2004
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69
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Oct 8, 2006
#6
  • Oct 8, 2006
  • #6
it's only on bank 2 though... wouldn't it show up on both o2 sensors? im guessing bank2 = passenger side. would this lead one to believe it's spark due to the jump in timing?
 

1991vert

10 Year Member
Feb 27, 2004
1,103
7
69
Ludlow, MA
Oct 8, 2006
#7
  • Oct 8, 2006
  • #7
i got bank1 o2 sensor lean today.
 

1991vert

10 Year Member
Feb 27, 2004
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Oct 10, 2006
#8
  • Oct 10, 2006
  • #8
what size injectors should i go with?
 

jrichker

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Oct 11, 2006
#9
  • Oct 11, 2006
  • #9
1991vert said:
what size injectors should i go with?
Click to expand...
For a 347, I would use 30's with a matching MAF.

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines.

Example:
19/.5 = 38, 38 x 8 = 304 HP
24/.5 = 48, 48 x 8 = 384 HP
30/.5 = 60, 60 x 8 = 480 HP

The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.

304 HP x .85 = 258 HP
385 HP x .85 = 326 HP
480 HP x .85 = 408 HP

Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.

See http://users.erols.com/srweiss/ to get the calculators used in these examples.
 

88Stang331

New Member
Mar 30, 2006
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Oct 11, 2006
#10
  • Oct 11, 2006
  • #10
jrichker said:
Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors.
Click to expand...

I didn't see it before...but you are deffinately a tool...you could have just multiplied by two and made it easier for us less smart people. (not gonna mention any names)
 
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