I had 305 TPI,I now have 350 TPI.What's in it,AFPR,24# injectors,Hypertech chip,2200 stall ,Flowmaster ehaust,Stock motor w/flat top pistons,Hydralic roller.No hedders yet and no super coil.My problem is no power over 305,SES comes only after 10-15 min. of driving w/ codes,EST,MAF(new)O2 sensor but was unplugged.I run 93 octane but car still pings no matter where timming is set.After 3000Rpms car has nothing and vibrates .This car should run better than the 305,now the data stream on the scanner shows to be running open loop and lean but I have plenty of fuel .I raced a 99 GT from 60 up to 100 and I could not pull on him but stayed w/ him .I don'tknow what to do.Mind you I had no problems before the swap no codes no vibration,nothing.please help

 

86 the hypertech chip and turn down the fuel pressure(I would know from experience)

 

Did you change the memcal? I think the 305 to 350 are different. If I am wrong somebody correct me please.

Nope sorry I was thinking of MAP and MAF memecals they are diff. I think they are same for 305 and 350.

[This message has been edited by 86 IROCZ28 (edited May 19, 2001).]

 

memcal is probably different,,maybe. But the knock sensor is. You need a knock sensor for a 350. Try that first.

 

a 305 tpi chip and a 350 tpi chip are different.the 350 tpi chip has a more aggresive fuel curve to it.
do you have a 305 chip in it?if you do that's your problem
what do you have your fuel pressure set at?for a pretty much stock motor you should be betweeen 42 -46 psi.
did you put a new timing chain in?do you have the gears dot to dot?did you bring it up to top dead center when you put the timimg chain on?
is the o2 sensor and knock sensor from the 305?i'm not sure about the o2 being different but(i'm pretty sure it is different)the knock sensor is different.
what year car and what year motor are you working with?


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1991 banditt2 #130 of 600
Project 350 TPI Banditt II
http://www.street-dawg-racing.cityslide.com
http://discussion-board.com/GreaterC...dyAssociation/
http://www.cincyspeed.com/

 

Everything was done correctly.The O2 and knock sensor are bothe the same for 305 and 350 as I checked part numbers w/GM.The engine is brand new and was put together at the place I ordered it from,my O2 sensor was unplugged so I fixed that but my main problem is the exhaust pipe being bent so untill I fix that I won't be able to get the diagnosis.As far as chips go I have the Hypertech for 350 and I even put my 305 stock chip in and it made no difference in power.My fuel pressure is at 48PSI and I have checked the plugs and are runinng perfect.It has gotten a little better as it breaks in more each day.My car is a 87 and the engine I orderd is for 87.

 

Hmm... 24# injectors and 48 psi dont sound right on a stock engine, and try replacing the knock sensor anyway, maybe try cleaning out your stock 305 inj.s and put them in with that high press.

 

What heads are you using??? I may have missed it, but if is the LB9 head with flat tops, I think we found your pinging problem. I don't have the formula on me but flat tops+350CI+58cc chambers=kaboom!

 

my buddy has found that on a stock LT-1 with 24lbs injectors he runs his best times with the fuel pressure set at 42psi

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1991 banditt2 #130 of 600
Project 350 TPI Banditt II
http://www.street-dawg-racing.cityslide.com
http://discussion-board.com/GreaterC...dyAssociation/
http://www.cincyspeed.com/

 

camarocowboy, any luck with your engine. I just got mine back today and am having the same problems.