I had much the same issue when I first changed over. I had the 45# injectors for the 305. So I upgraded to the 55#. Things are better, but I don't know if the 7727 computer is set up for the 9C1 PROM. Mine is much better with the 55#, and I think it is matched to the computer. I think mine is like the truck program for the 350. With the higher compression and mild cam in my engine, I know it could be better though. Just don't know how to go about changing it. There is a spacer that goes in there to raise the pods, that you can get for about $10 on eBay, that is said to dramatically increase the air flow. Even more than boring the throttle body and intake would do. Check it out. I don't know if my injectors could compensate for the increased air or not, but I am sure your setup could. It would be interesting to figure out if I could swap to your ECM, Injectors, and 9C1 chip and go without any other mods. I believe you have an air intake temp sensor that I don't have. I don't know if it was in my harness. Will have to look. Glad you got this figured out! JC --- John Christensen Saint Charles, IL On Wed, Oct 21, 2009 at 4:44 PM, Jared Ryan <jryan@xxxxxxxxxxxx> wrote: > I recently started wondering if my El Camino might have fuel injectors that > were too small. One of the main reasons is that with the 350, the idle had > never been stable, tending to hunt badly, and lately cold starts were > getting to be more and more difficult. It would fire after five or six > seconds of cranking, fire, then die after 20-30 seconds. I'd have to > restart it, sometimes more than once. > > With Robert's help, I found that I had a Caprice 9C1 PROM with pickup > injectors. Pickups had 55lb./hr. injectors, while the Caprice had 65lb./hr. > injectors. So, my injectors were 15% smaller than the PROM was programmed > for. > > I put the injectors in, but was interrupted in my testing by a battery that > abruptly decided to go dead after a cold front blew threw. I put a new > battery in last night, warmed up the engine, and set the minimum air > adjustment. Then I put up all my tools and went to bed. > > Today, after I came home, I put the key in and started it. WOW. That's > what I'm talkin' about! It fired after about 2 seconds, jumped up to a > stable fast idle at 1400-1500 rpm, then very, very gradually began to slow > down after a couple of minutes, settling down at a steady 800 rpm with no > hint of hunting, running very smoothly. I didn't drive it, because it's > clean and it's going to rain at any time, but it was very even and sounded > great, and didn't smell rich. > > So the moral of the story is to make absolutely sure you use fuel injectors > that match the PROM on any fuel injection project. I can't believe it took > me *years* to realize I had a mismatch. > > ---> Jared Ryan <--- > jryan@xxxxxxxxxxxx | http://www.caminofx.org > > > > Rules: Please play nicely with others. > > -List members page (text & pic links): > http://www.myelcamino.net/eclist.htm > -List members page (all pics): > http://www.myelcamino.net/ec_list.htm > >