Hi, I recently swapped my old carbeurated vortec 350 into my tpi car. However when I try getting it to run it will only run at 60* advanced.

I synced the distributor to TDC as usual and verified that my wires are hooked up to the correct firing order. But it idles like it has a miss or I have wires crossed.
if I idle it up it smooths out but the headers get red hot.
the only thing different between the 2 engines is the tpi intake and efi system.

Is it possible the computer is advancing the timing to this extreme or is likely something mechanical?

 

Are you certain the marks on the balancer are correct, verified with a piston stop or some similar method?

If the balancer mark is in fact at true TDC on the crank, the valve timing could be a couple of teeh off the proper cam timing. Late valve timing could account for some of the symptom you describe.

If the replacement engine (with carburator) is still using the ECM from the TPI system, there are likely to be more issues than ignition timing.

 

Yeah im going to verify that my marks are correct right away
but it does seem like cam timing is off.
If i remember right, the carbed engine was running well before I started the swap (it's been a few years)

What are some of the typical issues that arise with switching a carb to ecm?

Thanks

 

A factory ECM is going to need a TPS input to control timing advance. For an '87 it is also going to want a MAF input.

 

Headers get red hot = timing is WWWWWAAAAAAAAAAAYYYYYYYYYYYY retarded

If your "marks" say the timing is advanced, THEY'RE WRONG. Most likely, you have a stock balancer with the "mark" at near 12:00 when #1 & #6 are at TDC, but an aftermarket timing tab with the "mark" at 1:30, such as for an earlier style of damper.

Put the timing where the motor runs the best. Ignore the marks. "If it RUNS good, is IS good". Don't outsmart yourself over abuncha "mark" and all that. Let the engine tell you whether it's right or not. You can advance the timing until it starts to ping (if it's not pinging now, then it's NOT "crazy advanced"), then back it off until it just barely quits, to give you some idea about where you are. That's probably not "the right" setting by any means, but serves as an excellent benchmark and troubleshooting and of course mark verification technique.