I finally fired up my Vortec 350 w/454 tbi on the 4th of July. Took me 6 months of work to assemble and install the engine in my car. The car started up but would only run for about 20 seconds or less then the engine would shut off. Took spark plug #1 off and noticed it was black but did not see any black smoke come out of the tail pip. The car has a heated O2 sensor since I have SLP headers and no egr valve (no provision for egr valve on Edelbrock’s Vortec Air Gap manifold) Tried running the car with the IAC on and off and still the same results although she did run a little longer with the IAC off. Unable to set the timing since the car will not operate long enough to set the timing. I would love to at least get to drive the car before going on deployment on the 16th of this month. Any help would be appreciated.

 

You can set the timing by ear and with a vacuum gauge. With the engine running, rotate the dist. counter clockwise to advance it (I think) very slightly untill you find the area that the engine idles its best and pulls the most vacuum. This should keep it going long enough to set the base time. Also dont be afraid to add a degree in or two of base advance since the stock timing tables are sort of lame.

 

Have you tuned the chip or are you using the stock one? Since you are not running an egr system you might want to be careful with the timing. You could run into detonation problems. You didn't mention what size injectors you running. If there the 80 or 90lb injectors and you're using the stock chip I would agree that you are running very rich. If you have the stock injectors you might put those in untill you can burn some chips and see what the engine needs.

Steve

 

Still no go on timing the car. Engine would not run long enough to adjust the timing. I installed a 2nd 454 TBI with 90 # injectors and still it dump a lot of fuel. As far as chips goes, I purchased one from tbichips.com. Removed the chip and sent it back for him to tweak. Hopefully I will get the chip back in time before I deploy. I just finished removing all 8 plugs and draining the oil and replacing the oil filter. There was some gas mixed with the oil from running too rich. The car sound good when it did finally run.

 

I'm way new to TBI, but recently picked up a '91 RS with LO5 (350) and Caprice injectors (??about 65#'ers?) installed, running on the stock L03 chip, it ran quite a bit on the rich side until I backed down the fuelpressure...Based on that, I'd wonder if you have too much injector for the stock chip to control?

 

nope, the tune is just way off. I would be seriously surprised if you get out of the driveway on the next chip. It'll take 4 or 5 tries to get you where you can drive it around. Of course if you were doing it your self it would only take about 30 minutes.