I have a freshly re-built TBI 350 I'm having a terrible time setting up the ignition. Wondering if I need a new module, or possibly a new distributor? It almost seems like my distributor is switching between two different timing curves while I"m trying to set my initial timing WITH the ESC wire disconnected. Sometimes when I'm setting base timing to 0 BTDC for base timing, it seems like I need to really turn the distributor advanced to get to 0.... then once I re-connect the ESC wire, it runs terrible at like 60+ BTDC at idle. Then if I disconnect the ESC wire again, and look at base timing, suddenly it actually is advanced?? and I need to pull it back in like 20 degrees. Here is the catch, after I go through this dance and set the 0 timing with this "new curve" once I reconnect the ESC wire, the engine will start and run the first time and timing will look good (28 advanced at idle). But after I shut her down once...she won't start again, almost like she is flooded (can you flood a TBI engine?). I've got fuel, spark and compression, but she won't catch, just spins over. After she won't start, there is nothing I can do but wait (no timing position works), if I wait until the next day I can readjust the timing to the original base timing (the one that seems advanced based on distributor position) and she'll fire right up and we begin the dance again. The distributor I'm using is the oringal with over 209k miles on it. Also, my spark pluges are jet black with carbon build up, they look like black velvet! Is this related? I've hardly run this engine more than 5-10 minutes at a time. I have new plugs and wires. Should I just bite the bullet and get a new distributor? Anybody know how the ECM-controlled HEI distributors work? How do they actually advance the timing (mechanically speaking)? Thanks!

Although I might not be able to help you, I have a feeling of what is coming:

What year/engine/FI type/etc. did you originally have in the vehicle?

Did you get a new chip once you put the new engine in?

Trick414,

I had an 89 350 before, now I have an unkown year but fresh rebuilt TBI 350 with a TBI cam.

but I think I've solved the problem, one thing I didn't add to my post (Becuase I didn't think it was related at all!) Was that my ECM was throwing a 15 code for my coolant temperature sensor (CTS).

After working hard all day at work yesterday (reading forums!!) I read a number of posts where people thought they were having ignition problems, but it ended up being the CTS making the misture WAY too rich.

I knew sooty spark plugs can mean too rich A/F ratio....and combined with the 15 code...I got all excited ran down to the auto store, picked up a new CTS $11.99...ran home threw it in and WAHMO! No problems truck starts better, timing and everything seems to be lining up!!


And let me tell you, the spray cone from my fuel injectors at idle is WAY smaller than it was before..I can hardly see it at idle now with a flash light in the dark...where before it was like a garden hose on spray pattern.

So lesson learned, if you are having what you think is a ignition gremlin...don't forget about the CTS sensor...it is the major controller of A/F ratio...more fuel when coolant is cooler.

Thanks guys for all your help on here, this was just he latest in a strong of problems I've gotten help from this form on.