new engine troubles...

[1991vert]

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]

bump

 

[bob331T76]

have you had it tuned yet, my 331 ran like dog poo until i got it tuned , picked up 67rwhp too!!

 

[jrichker]

Code 91 can be a vacuum leak or bad O2 sensor.

 

[Grn92LX]

Vacuum leak!!

 

[1991vert]

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]

i got bank1 o2 sensor lean today.

 

[1991vert]

what size injectors should i go with?

 

[jrichker]

what size injectors should i go with?

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]

Injector HP ratings: divide flow rating by.5 and multiply the result by the number of injectors.

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)