Ok ... i just added the following to my 305:
lt4 cam, vortec heads, powerplus intake, holley 670 with stock inj. pod, bottom end rebuild.

Here's the deal with it. I was setting the timing, and i started out at putting in about 4 degrees advanced. Well it would backfire through the intake at 4, and didnt seem to have a very tight throttle response. Looking back I realized that I was probably running lean on acceleration. So I kept cranking up the timing. Right now its pretty advanced, way off the timing scale thing. And it actually runs 1/2 decent, and doesnt give any codes, and my scanner isnt showing any knock (might not be the real case though). 1st gear will pull like *** is yanking it on a string, then 2nd gear seems to bog. The more load on the engine the more it bogs.

I talked to my brother the other day and he said adding that much timing was just like a bandaid to mask the leaning problem.

Do you guys have ANY tips for me? I have a hypertech chip in the attic, does that add more accel enrichment? Can I adjust TPS to add more fuel? Im afraid that im gunna burn a hole in the piston or something if i keep driving it like this. I dont have much money left, so I cant really start burning my own chips.

ALSO, on a side note, I have a new cooling fan switch, can I put in on the intake manifold instead of the head if i just splice a little wire in? THANKS

 

Did you remember to unplug the tan wire before messing with timing???

 

yes

 

Are you running the stock 305 injectors and at what PSI?

With mine I needed around 9* of advance to get it to have a resonable idle. DM91RS is running the same heads and cam on his LO3 you might try to PM him.

 

Im running stock injectors with the regulator maxed out

 

could you be 180* out? Shouldnt need that much timing. Everytime that my dissy has come out and gone back in it hasnt given me problems. Last time I pulled it out and stabbed it in it was only 2* off. Started fine and didnt backfire or anything. BTW when I started her up she was running 2*ATDC w/ no backfires or problems. Right now shes running at 12* BTDC w/ 160 thermostat in +100* weather with no problems or overheating. Something in your timing has to be off. Did you install the cam straight up? Check all your basics first

 

those stock injectors are probaby nowhere near enough. On my stock 350 i ran those 45 pph with the regualtor turned all the way up and it ran lean enough to instantly vaporize the paint on my headers and make them glow a nice incondesent cherry red in a matter of about a minute. Your engine definatly needs more gas than mine does with all those mods.

Needless to say i promptly went out and got the 55pph ones. Not the best but they keep the blms in reason and it doesnt run lean.

 

I ran with the Holley injectors (i dunno what #) but they fouled the plugs and generally ran crappy. They were the old style injectors with the black caps.

Where can i get injectors for TBI anyways?

 

Get some 350 injectors off of a wrecked full size pickup between 87-95. Just make sure the engine is indeed a 350. That should be plenty along with a chip to tell the ecm to give you that extra fuel.

A fuel pressure regulator might also help after this mod.