So let me start by saying that this has been a real pain in the @$$. But, here goes nothing.

Car was originally a 305 TBI Iroc-Z. It has since been converted to the following:

L98 350 TPI (using DynamicEFI, modified engine harness and PortMod)
Cam- Crower, 204*int, 210*exh, .484in intake, .505 in exhaust, 114 LSA
Heads- Ported 113's with springs for higher lift cam

Car started giving me problems while driving across the country, died on the way due to ruptured fuel line in tank (PITA to figure out). Then the fun started.

Wouldn't run right when warm, stalled, erratic idle, refusal to start, etc. Checked injectors, 2 bad from stock Multecs. Replaced with FIC injectors, 32#'s in case of forced induction down the road....also installed AFPR to help tune with larger injectors.

Now, refuses to run as it warms up. Car isn't quite fully tuned, still using stock LB9 spark advance tables and PROM, except for modified BPC v VAC (Base pulse constant v. Vacuum) table for larger injectors. Believe it or not, car actually runs lean most of the time, or so it says. I know I need to

Have been using Dynamic EFI on my laptop to check running conditions; nothing out of the ordinary, no check engine codes, no nothing. AFR from O2 sensor says its running around stoichiometric (14-15). Something worth mentioning, when engine does idle (on cold start), pulls about 17inHG vacuum steady....is this normal? Its not that radical a cam, it should pull down more than that, at least I think it should.....

The second the car gets within temp and runs for 30seconds (thus putting it in Closed Loop Mode), the idle drops, jumps around between 900 and 400 RPM, then stalls. Also, when it gets hot, the Knock sensor reports pinging and the spark retard kicks in for higher RPM's. Why?

From what I can tell, all sensors work properly. IAC and TPS were replaced and reset recently; CTS, IAT, O2 sensors display sensible values. Fuel pump was replaced a few months ago, as was the fuel filter. As stated above, injectors are brand new FIC Bosch Design 3's.

I've done some research, and many people suggest replacing the Ignition control module under the distributor....why would it do this upon entering Closed Loop?

Besides a good tune to accomodate the gigantic injectors and checking the hot and cold resistance of the Knock sensor and possibly replacing the Knock filter, what else can I do?

If anybody has any Ideas, it would be greatly appreciated. Please, throw anything in here that I haven't tried. I'm all ears.

Please note, I will be posting this thread in the DFI/Prom Tuning board. I figure the more educated people that know about this stuff, the better.

 

I'd also like to mention that the EGR and smog pump have been removed. The only reason the EGR is taken off is because the '113 heads do not have crossover passages, and the smog pump was simply removed.