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350 Buick TBI Cam

3K views 4 replies 4 participants last post by  mnstreetrodder38 
#1 ·
I have a 1993 Buick T.B.I. 350 wih an OE hydraulic roller cam that i put in a 38 chevy. I have run all the wiring and all the sensors i need are there and I am using the stock computer. The stock engine was runing perfect lst year and overthe winter i decided to do an overhaul due to how many miles it had. I had the heads shaved due to being warped, roller tip rockers, double roller timing chan, edelbrock performer t.b.i. intake, 180 degree thermostat, mallory ignition coil, custom exhaust, just little tid-bits to mildly help performance an longevity of the engine. I also added Comp Cams "computer controlled" camshaft #08-300-8, specs are .450/.480 lift, 262/264 duration (http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=211&sb=2 is the link if you want more info). I got the car started and went to time it and noticed the timing mark on the balancer was kind of jumping around. I matched the mark best i could and got it to idle perfect which it still does. The road test is where the problems came. If you give it over 1/4 thottle or andything over 1000 RPM it bogs an nearly kills itself. Once again i am using the stock computer and I'm sure the cam is the problem. I need any help i can get in selecting a cam that will work or anything I can do to get it tune right and I have been told several times tha th Buick computer cannot be re-progammed. Help!!!
 
#2 ·
mnstreetrodder38 said:
I have a 1993 Buick T.B.I. 350 wih an OE hydraulic roller cam that i put in a 38 chevy. I have run all the wiring and all the sensors i need are there and I am using the stock computer. The stock engine was runing perfect lst year and overthe winter i decided to do an overhaul due to how many miles it had. I had the heads shaved due to being warped, roller tip rockers, double roller timing chan, edelbrock performer t.b.i. intake, 180 degree thermostat, mallory ignition coil, custom exhaust, just little tid-bits to mildly help performance an longevity of the engine. I also added Comp Cams "computer controlled" camshaft #08-300-8, specs are .450/.480 lift, 262/264 duration (http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=211&sb=2 is the link if you want more info). I got the car started and went to time it and noticed the timing mark on the balancer was kind of jumping around. I matched the mark best i could and got it to idle perfect which it still does. The road test is where the problems came. If you give it over 1/4 thottle or andything over 1000 RPM it bogs an nearly kills itself. Once again i am using the stock computer and I'm sure the cam is the problem. I need any help i can get in selecting a cam that will work or anything I can do to get it tune right and I have been told several times tha th Buick computer cannot be re-progammed. Help!!!
Too much cam and maybe too much rocker if these rollers are a 1.6 ratio. TBI is pretty unforgiving about things that change ratios of manifold vacuum to throttle position. If you read the fine print you'll see this cam is for TPI engines not TBI engines. To make it run in a TBI engine will take a custom chip or you'll have to return to GM's anemic original cam.

For a chip check some of these:

http://www.fastchip.com/

http://www.tbichips.com/

http://www.hypertech-inc.com/

http://www.superchips.com/

http://www.tpis.com/

Bogie
 
#3 ·
If the ecm and wiring is oem did you disconnect the brown wire to the dist (I think) used to put the dist in base mode.Otherwise every time you move the timing the ecm moves it right back to where it thinks it belongs.The emission diagram from the donor would indicate which wire needs unhooked and its original location.
 
#4 ·
Set the timing about 1 degree more than stock for initial, that is with the electronic advance disabled. It may not idle perfectly because of the cam, but setting the initial on a computer controled engine by "what makes it idle best" is a big NO. I'm betting you left the electronic advance enabled when you set it as well as that would cause the spark to jump around.
 
#5 ·
Yea i knew about the brown wire thing, I did not have that and when i adjusted the distributor the timing did chnge and stay where i was at so tht part wasn't an issue. I am going to try and time it a little advanced and see if i can get a better result. And the roller rockers are 1.5 so they should be good cause that is what the stock ratio was. As for an ECM chip the Buick's chip cannot be removed and replaced like the trucks, it is a single unit. I am also considering going to a normal hydraulic lifter cam cause i have ben reading people with the truck T.B.I. have been having better luck. And i suppose that is my fault about the TPI mix up. But everybody thanks for the help so far
 
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