First timer here, anyways down to business. I just swapped out a tired 305 tbi with one I bought used. The engine is a 350 bored to 355 with what I was told a 95' block. Has vortec heads, summit intake and Camaro cam. My problem is it starts fine, idle is lopey, goes up and down like it's searching. When I start driving, has a 4 speed, it wants to cut out than will catch it breath, when I step on the pedal further it misses and sounds like it's starving itself of fuel like a sputtering noise. Tried all the ticks on the timing plate and none seem to make it run better. The engine came with a computer but the intake has no egr port, I am not sure if it's deleted or not. I used the TPS from the 305 so I wouldn't have to splice the new connector in. Would that be my problem? Has new fuel pumps, swapped everything but the TPS sensor. Did not check for codes yet.

 

did you use a vortec specific intake?
i'd check for vacuum leaks and pull any codes. double check all the wiring is hooked up correctly.

 

Triple checked all connections and wiring, it's a summit stage 1 vortec intake. Inspected all hoses and throttle body gaskets and adapter plate. Unhooked the MAP sensor which made it run even worse, reinstalled that and still runs terrible. Codes will be pulled after work today.

 

TBI is pretty finicky about being tuned properly. Fuel tables need to be matched to the configuration you're running.

For instance, what "Camaro cam" are you talking about? If it isn't close to the original cam for which the ECM was tuned, then the engine won't be happy.

 

Yeah about that, the dude I got the engine from told me what it was but it was quite awhile ago I forgot what's it is from. I got it running not to bad right now checked codes got abunch for MAP, and EGR. Egr I don't think is deleted from the ecm as it is Acting like it needs it. Fuel filter was pretty dirty changed that out, added a 16lb regulator spring, those made it run decent. Still sputters accelerating, seems to be a dead spot where it lags than catches up with itself, I have the stock fuel pump was thinking of going with the EP381. Haven't checked pressure yet waiting to get a tester. It feels like it's not getting enough fuel for what it needs. Tomorrow I'll get the fuel pressure tested and see where I can go from there.

 

you might want to address the map error and see how much vacuum you have at idle. With the four speed are you running a vss ?

 

I changed the map as the one that was in there was faulty also the vacuum line connection wasn't tight to the back of the TB, cleared codes that problem solved. Ummm been awhile since I worked on vehicles what exactly is a vss?

 

Vehicle speed sensor, if you have a cable drive speedometer painless wiring (60115) makes a 2k ppm sensor. This will help the ecm to calculate fueling vs speed/load and control the iac especially during deceleration to a stop. A code 24 would show without a vss.

 

Yeah it's a cable drive, there's a orange wire that comes off one of the connectors to the ICM and a green wire outta the same harness hanging there. With my old 305 ran it like that no problems, maybe they need to be hooked up I'll check the schematics what they are. Since it ran fine before didn't think to find where they go.

 

Changed my ecm from the one the guy gave me to the one I had with my 305, world of difference it made can feel the power now, now I just need the 350 chips and should be good to go. Thanks for all the info anyways guys.

 

I have been thinking about doing this swap. I want a 350 , but would i be better off keeping the TBI or going to TPI?

 

ive had good luck with the sniper efi kits ive installed 4 kits and the customers love them