hey .. i have a 1991 camaro z28 convertible with a 5 speed manual ..


i just rebuilt the motor and put on :

summit racing vortec heads .. 1.94 intake .. 1.5 exhuast .. 170cc .. 67cc
edelbrock vortec tpi intake manifold
msd distributor cap / rotor
taylor 8 mm wires
comp cam 08-501-8 (212/218 .. 264/269 .. and around .480/.490 lift)
flat top aluminum pistons (5cc)
hooker 2055 headers / y pipe
bbk adjustable fuel regulator
.015 head gaskets (3cc)

i got the car running .. sounds really nice ..

but it drives like crap .. its reall sluggish and feels like it has no power

i have played around with the timing and fuel pressure .. and got it really good but i think i was overfueling it or something b/c it made a "pop" sound .. so i set it back

what would be good starting point for my timing / fuel pressure so the car will be "drivable"

and i noticed that some liquid spits out of the exhaust and makes little spots on the ground .. would this be excess fuel? .. or would that show me that the engine isnt firing on all cylinders .. or i tightened the rockers too much .. ( i took them to zero lash .. then one turn )


thanks,

adrian

ps- i dont have the money right now .. but asap i'll be tuning the computer .. the comp cam guys say this cam will work fine with the "stock" tune for now ..

 

fuel press w/ the vaccum off- 42ish
base timing w/ the wire unhooked - 6*s
I set my lifters at a 1/4 turn after they stop clattering (zero lash) w/ the engine runnin and aluminum foil pressed around the pushrod hole)
The condensation is normal unless it obviously raw fuel or oil. Smell it!taste it, and check your oil. Ok, maybe you dont have to taste it.

 

i've run that size cam with a stock tune and it was ok. if you didn't set your base timing you need to. don't guess. the ecm doesn't like that to much. as stated above, with the wire unhooked set to 6* before tdc with the engine warm. may also want to do the idle check and check the tps setting.

 

ok ..

ive talked to a couple people and so far ive been told :

10 to 12* btdc on the timing
around 46 psi fuel pressure ..

im running a mild cam and its kinda acting up right now .. but i dont have anything adjusted right ..

thats good that it isnt fuel .. i guess i could try taking a lighter to it .. hahah .. fire show .. ..

damn 1/4 turn .. i wonder if i should pull the covers and adjust them again .. that might be where my power is gone ..

thanks ..

 

I just did a 350 swap into from a cammed up 305. Both motors had similar symptoms but it was much worse with the 350. They both felt like they had no power, but it seemed to slightly improve at WOT. The 305 was pulled for other reasons.
Two things i did that helped the most were setting the timing proper and, for the biggest improvement, replacing the O2 sensor. Other sensors are on the way, but it runs almost like brand new.

I adjusted my valves to 1/2 turn, but i did it while the motor was running as well. Its very important to make sure the lifters are good and pumped up with oil before adjusting them too. If its running and you can see oil dribbling down the rockers, then the lifters ought to be pumped up.

 

i did the old intake valve closing/exhaust valve opening method to tighten my rockers. i tightened the nut till the pushrod was firm and wouldnt twist easily, and then went about another 1/2 turn of the ratchet. that sets the proper preload.

 

ok .. set the timing at 10 btdc .. and it sounds really good .. alot better than 6 ..

and i turned the fuel pressure up to 46

it became quiter and a deeper / meaner sound .. guessing thats good ..

but it drove good at slow speeds .. but higher rpms / speeds .. the motor was lagging again and it popped once or twice .. sounded like a backfire ..

do i need to increase the fuel pressure .. or timing ..

i got a new 02 sensor .. i guess ill try that first .. gotta go put it on ..

adrian

 

The pop may be "Lean Pop". I'd set the timing to 6 degs or a bit more, and try adding fuel. Set the fuel pressure to 49 psi and see if the Pop goes away.