new motor with timing problems

It's a 89 1500 that came with a 305. motor was getting tired, so i put a 350 in. It has cammel hump heads, 282 crane came with 1.5s on in. and 1.6 ex. roller tip rockers. air gap rpm intake, with a 1" spacer, and headers into side pipes. no egr and i put a 350 chip in the comp., 350 injectors and pres. regulator. msd coil, new cap and rotor, 369 modulater, 8.8 plug wires. the problem is when i set the timing to 0 deg. it ideals fine but as soon as you give it fuel, it spits and sputters out the tbi. the only way i can drive it, is to set base at 18 deg. and with the timing wire hooked back up it's at 38 deg.. it runs good their, but the low in power is sluggish. i know the dist. is set right i've check it several times to make sure i wasn't off a tooth. i've pull the knock sins. took make sure it wasn't giving a false reading. it has 18" of vaccum at ideal, so the map sins. should have plenty. thier are no eng. codes. i'm at a loss, do i need to have a chip programed or am i over looking something?

Did you install the cam straight up? What did the card that came with the cam recommend? Did you degree the cam?

//2000CAYukon

yes the cam is straight up. no card, the block came out of my buddys vette. the bottom in was good. we just swap it out for a big block. i did pull the timing cover and check the chain and the setting on the cam.

Cams and computers don't alays agree so that being said I'd recommend have a new chip burnt for your application. Don't just buy any old so called HP Chip get one made for your application.

Do you know the specs on this cam? Lobe separation is important in computer controlled engines.

//2000CAYukon

no i don't know the specs. but i was wrong on the cam size.. it's a comp high energy 268h. and it has 1.5 on the int. and 1.6 on the ex. .

valve timing .006 lobe center 110 int center 106 duration int. 268 ex. 268 valve lift int.0.454 ex. 0.454 lobe lift int. 0.302 ex. 0.302
int. open 28 btdc close 60 abdc ex. open 68 bbdc close 20 atdc

hi i hope i can help the cam you got is perfect for upgrade with computer engine. i like that cam myself.with them cams unplug the est to set timming between 8-10 i suggest 8 to start then plug the connector back in a restart and test drive it. Now i hope you didn't put in a geardrive as that is your problem computers and geardrive don't mesh.The eprom might be the wrong one for your set up.Can you give me the eprom number so i can look it up for you and tell ya what you need to change. Only difference with injectors is v6 v8 and small block and big block . Pretty much they are the same.but im betting the eprom you put in has different map then the 305 one you took out .The 305 one should work without a problem.But test the 8-10 timing out first if it don't work send me the eprom number/letters i can work with ya.

I agree that this cam should be fine for a computer controlled TBI. Is the MAP connected to the TBI correctly at the back? Make sure the vacuum port and hose is clear to the MAP.

Might also be a good idea to get a scanner on it and see what the sensor are reading.

Good luck,

//2000CAYukon

yes i have the map sen. hooked up right. i didn't at first, i had it torn apart to long and forgot where it went. so i looked and a buddy's truck. i don't have any codes. i did find out the map reading on the 305 are slightly different than the 350 chip. the chip i have in is 1227747 amur. and i tried a 1227747 asdu but it didn't ideal as good as the amur. i've tried to back the timing down but anything below 16 and it pops and trows flames out the tbi, when you try to rev it. i did notice that my volt gauge was showing only around 11 volts. so i checked the voltage at the battery 12-13 and then the alt. which was 13-14. so ran a wire from the alt. to the battery which brought it up. i haven't tried to retard the timing yet,since getting voltage right, will tonight. i took it on a little under 600 mile trip yesterday with no problems. but i need to get the timing right because its hard to crank when its warm and it not getting its full power.
thanks for all your input and help.

Thomas
89 ck 1500 350
79 caprice 388 stroker
88 fiero 4.9l v8 nos

well i backed it down to 8 deg. and while it was running with timing wire disconnected i rev. it too 2500 rpms and the it went to 28 deg.. with the wire disconnected and their are no weights inside the dist., why would the timing change? was the comp. adjusting, even with timing wire not hook up?. after i plug the wire back in, it ran fine. but it has the stumble when you rev it up. took it down the road, and it preformed better. once your going, but taking off you have to ease into it. or it will spit and sputter, seems to get worse as it warms up.