Any progress? I have an 89 S10 I did basically the same swap and am watching this thread closely.
Any progress? I have an 89 S10 I did basically the same swap and am watching this thread closely.
It turns out the BPSA memcal was programmed for an auto tranny and 5.7 injectors. I sent the chip off to have it checked out and reprogrammed since I have a 5-spd and was using the 4.3 injectors. The chip was cleared and programmed for 61 lb/hr injectors and everything fixed for the 5-spd.Originally Posted by 89S10_Project
I received the memcal back this week, but haven't had a chance to try it out or install the correct injectors. I was unexpectedly sent out of town on a business trip this week and with the holiday, I probably won't get a chance to work on it until next week. I should have the correct injectors this weekend. I'll keep you all posted.
I am not an EFI engineer, buuut:
The engineer in me says that the 4.3 injectors, while they may be made to work with a longer "ON" time, are going to be overworked and thus have their functional life shortened. Seems like it would be much smarter to go with the proper 5.7 injectors, especially given that they exist, are the same form factor, and will bolt right in place of the 4.3 units. (In fact, this is exactly what I did on my build, and why).
This may not be borne out by folks with much more experience in this area than myself, in which case I'll just file it away for future reference.
Pardon if this has already been covered - my head is awash with GMEFI stuff and it's all running together- is your truck's configuration somehow rare? If not, what's wrong with picking up a factory ECM for your engine/transmission off of Ebay, car-parts.com or a local salvage yard? I've never paid more than $50 for an ECM, and that was shipped to my door. Just seems like a really easy, cheap and simple solution, especially if you're resorting to having folks burn PROMs.
The 61 lb/hr injectors that I'm getting are for a 5.7.
My K1500 5-spd came with a 4.3 and I swapped in a 5.7 reusing my original wiring harness, ECM, , TBI, and everything on the front of the engine. I thought all I needed was a memcal for my 16197427 ECM to finish it up and fix the low idle and low rev-limit issue I was having. Apparently, there was not a 5-spd 5.7 k1500 made with my ECM. Changing to the stock ECM for my truck and engine would likely not work with my harness and sensors.
The BPSA memcal from a 5.7 van was available for cheap on ebay and was compatible with my ECM. When I tried it, the truck surged at idle. Everyone (before I joined this forum) told me that the 4.3 injectors would work fine. This was probably the cause for my surging issue. Because I bought it used from ebay, I thought it would be a good idea for someone who knows what they're doing to make sure the memcal was in working order and to make sure it would work in my application.
That's when I found out that the BPSA would not work with my 4.3 injectors and that the tranny needed to be changed from auto to manual in the program. I'm not an EFI engineer either and just getting started learning the terminology on here. Maybe soon I can figure out how to make my own changes.
Gotcha, and now I recall all of this. Sorry for making you repeat yourself.
Yeah, I'm right there with you, and totally agree on your approach. I hope it works out soon!
Posting Permissions
Reply With Quote
Bookmarks