Originally Posted by
mxatunerjg
I've been reading through this whole thing. Honestly there are so many different people having issues here I had trouble keeping up with who was having what issue.
I do agree with you about injector timing capabilities would be helpful. That said I would be a little surprised if the difference in the Edelbrock heads and factory heads is drastic enough to cause the issue you are having. Not saying it's not possible, just would be a bit surprised.
I have 2 thoughts about the issue otherwise...
1. I know it is simple and maybe seems stupid, but have you checked fuel pressure at the rail on those starts that you are having issues with? The fact that it is good on a quick restart hot, as well as a cold start, but a delayed restart hot causes a problem is one of those basic things that causes me to immediately look at fuel flow/pressure issues. On early efi systems with inline fuel filters an old dirty fuel filter would cause this kind of problem. If you would cycle the key prior to cranking and allow the system to build fuel pressure it would fire up on the first starter cycle. The stupid part about it is the vehicles generally would start fine on a cold or quick hot restart. It's probably not likely, but if it were me I'd check it because it would make a lot of sense for your issue. I always believed it to be caused by the fuel on the intake runners would evaporate off over the 20 mins of a hot engine sitting, then your prime pulse and injector pulsewidth during cranking on a hot engine was so low if the fuel flow/pressure wasn't there it caused the engine to be too lean to start. By cranking it some fuel flowed, and then when you went to crank again it would have some amount of fuel on the runners, and you have some fuel pulse from the injectors causing it to be much more like a 5 minute sit time on a hot engine. On the cold engine, the injector prime and pulsewidth were not programmed to rely on wet runners, so the engine started like normal. Obviously if the fuel flow was too low it would not work in any situation, but over the years I've replaced a lot of fuel filters or leaking in tank fuel lines that fixed this exact issue.
2 You said about checking coolant temp, but I would look at intake air temp. I don't know where you have the intake air temp sensor installed, and what type of material it is sitting it (alum, plastic, rubber, carbon fiber ect.). I've had a lot of issues with heat soaked IAT sensors give issues like this over the years as well, basically it would be a situation of a sensor reading hot but an actual air charge temp that would be much lower. Based on the injector pulsewidth you said you are seeing I'd doubt this is the issue, but it is worth checking. If you have an intake temp sensor showing 200 degrees at startup it could be causing some issues with cranking ignition timing and fuel flow.
Just some quick thoughts I had when reading through this.