94 K3500 454 Vortec

[X-man]

Was the flooding problem tied to anything?

Best I can figure is something in the 7427 ecm was not happy being converted to run the multiport setup. I bought an extra set of injectors and a brand new distributor to see if that made any difference and it didn't. I checked and rechecked my wiring and I also had another 7427 ecm converted with another memcal and it still did it. Once the Dynamic EFI ecm was installed it has not happened since and I made a point to prime it everytime on start up to make sure. Again you don't have to prime it but that is a habit I got into with my 97 S10 because of a bad check in the fuel pump letting the rails empty leading to prolonged cranking. I actually was curious if maybe the distributor was landing on a tooth in the pickup wheel causing it to trigger something. I would get out and physically unplug the injector adapter and start it to run all the fuel out of it, then plug it back in and it would be fine.

[ras"86]

Best I can figure is something in the 7427 ecm was not happy being converted to run the multiport setup. I bought an extra set of injectors and a brand new distributor to see if that made any difference and it didn't. I checked and rechecked my wiring and I also had another 7427 ecm converted with another memcal and it still did it. Once the Dynamic EFI ecm was installed it has not happened since and I made a point to prime it everytime on start up to make sure. Again you don't have to prime it but that is a habit I got into with my 97 S10 because of a bad check in the fuel pump letting the rails empty leading to prolonged cranking. I actually was curious if maybe the distributor was landing on a tooth in the pickup wheel causing it to trigger something. I would get out and physically unplug the injector adapter and start it to run all the fuel out of it, then plug it back in and it would be fine.

What conversion was used for mpfi? I'm considering doing one to my 94 suburban, going with a 98 L31 and 6395.

[X-man]

Not sure which part of the conversion you are asking about but the mechanical was an L29 top end with Fast 36lb injectors and an L19 distributor. Fuel lines were custom. The ecm started as the original 7427 ecm and was swapped out for a Dynamic EFI EBL Flash II with port mod.

[ras"86]

Just trying to understand if it was something in the changes posted by 93V8s10 MPFI.zip. Posted here. Thanks.

[X-man]

Just trying to understand if it was something in the changes posted by 93V8s10 MPFI.zip. Posted here. Thanks.

The best person to speak with on that would be David at Old School EFI. He is a wealth of knowledge on that kind of info. I know when I started this process he sent me an email on the process I would be more than happy to forward them to you if you want to email me. Supraman500hp@gmail.com

[ras"86]

I may do that, Thanks.

[dave w]

I've been successful with several MPFI conversions. I'm dumbfounded what was causing the flooding. The origins of the MPFI conversion were from HP Tuners.