i just rebuilt my 305 tpi motor in a 1991 camaro z28 convertibe

i put on:

summit racing vortec heads
comp cam
edelbrock vortec tpi intake manifold
hooker 2055 exhaust
flat top pistons
bbk adjustable fuel regulator
complete rebuild
and all new sensors

now it started first try when i built it .. and i played with the timing and fuel pressure .. ended up with 10* btdc / 46 psi

it ran fine yesterday .. just needed a little more fuel i think ..

but i started it today and drove it out of the garage and it sounded good .. but right as i got out the motor stumbled and died ..

have no clue why it did this .. but ive been playing with the timing all day and it wont start unless its soo advanced i cant see the marker with the timing light .. and even then its not running on all cylinders ..

it keeps flooding .. and it will run one second .. and then wont the next

i checked the codes and its throwing a "43" code .. which has something to do with the computer controlled timing .. which would make sense ..

also .. when i got it started again .. it was throwing out white / grey smoke (its 40 degrees here) .. and some fluid was spitting out of the tail pipe .. might of been excess fuel from trying to start it all morning ..

can someone please help ..

only thing i could think of is my computer is fried?

(before the rebuild the motor "hung" at a high idle before returning, and the chevy dealer said it might be a faulty computer)

but ive replaced all the sensors / distributor / etc

 

Need to see if you are getting spark, and injector pulse. Need to check fuel pressure.

EDIT: My bad. Check your post in the TPI forum.

Since it was running fine, and then just died, I would suspect the ignition module, in the distributor.......

 

the distributor / ignition module are brand new ..

but you think it could be faulty ..

actually im gonna go pull it and get it tested just in case ..

if not .. im thinking its the computer that is faulty ..

had a "idle hang" when i pushed in the clutch before i rebuilt the motor .. and the dealer said it could be a faulty computer .. so idk ..

thanks,

adrian

EDIT: when i advance it a bunch, it trys to start and kinda stumbles like only a few cylinders are firing .. but everything is new, distrbutor, cap, rotor, plugs, wires, coil, etc ..

also .. ive set my fuel pressure at 46 psi b/c of the extra air flow with the heads, cam, exhuast .. checked it and its still at 46

 

Just because the module is new doesn't mean it isn't bad and don't rely on the results of a parts store test either. Had this happen at a local Advance with a module that tested bad but was in fact good.

 

aight .. well im gonna take it off and test it myself too then ..

do yall think it could be a computer failure ..

also ... where is the computer?

thanks,

adrian

 

Magnetic pickup coil will trigger this codes and cause bad fuel odor and heavy misses.

 

I have some questions, and thought I would bring this thread back. I was heading up a steep hill today and hit the throttle. The CES light came on when I did this, so I stopped and checked the code...43. It has also been stumbling and missing a little bit lately.

Is the magnetic pickup coil that was mentioned the coil in the top of the distributor?

 

its been a while (couple weeks) since i have been tinkering with my 91 z28 ..

but if i remember correctly there was a star shaped thing under the rotor when i took the cap off that hooked up to the ignition module .. everything in the distributor is under the cap except the little gear at the bottom ...

i go to college and drive about 500 miles a week so i had to buy something a little better on gas, ended up with a 91 mr2 turbo .. i must say it makes the camaro feel like a cruise ship instead of a speed boat .. lol .. but they both got there positives and negatives .. for example the mr2 is in the shop for a coolant hose, where as the handy camaro is sittin waiting for a thrashing ..

 

Just a suggestion... When you adjusted your timing did you unplug the connector near the heater box? IIRC this sends the signal to the computer of what position the dist is actually in. When adjusting timing on a computer controlled setup it cannot be properly set without disconnecting it, setting timing and reconnecting. A search might give you more information. My $.02. -Bob

 

yea i disconected that wire ...

got everything sorted out since then, and ive been tuning the computer a little

 

So, what was the problem?