More Fuel Pressure?

[iamtall77]

I'm running a 4G63t with a 14b, 2G MAS, 255lhp pump and stock 450cc injectors on my 89 Colt GT. I have an adjustable fuel pressure regulator and SAFC-II to tune with using my Palm and MMCD. I am running a 90 turbo ECU, but my fuel trims are way off. I richened the SAFC to +30% and I'm still getting 118% or so on my low fuel trims. This is running at about 40psi on the AFPR. I already bumped the static pressure to about 50psi to see what would happen. Was that a good choice to help leave some room on the SAFC to tune with? Is that going to mess with anything like the linear movement of the fuel pressure the engine is used to? I've only tried tuning once with a 2G MAS, but had some 550cc injectors to work with. I'm not worried about running out of fuel or anything since I'm only running 10psi on the 14b right now. I'll bump it to 16psi or so when things are working right. Any advice would be great.

[Hydro]

It would be better to stick with known fuel pres. Base fuel press is 43 psi, with vacuem it should read 38 psi, start tunning from there.

Kenny

[burnett03]

I'm running a 4G63t with a 14b, 2G MAS, 255lhp pump and stock 450cc injectors on my 89 Colt GT. I have an adjustable fuel pressure regulator and SAFC-II to tune with using my Palm and MMCD. I am running a 90 turbo ECU, but my fuel trims are way off. I richened the SAFC to +30% and I'm still getting 118% or so on my low fuel trims. This is running at about 40psi on the AFPR. I already bumped the static pressure to about 50psi to see what would happen. Was that a good choice to help leave some room on the SAFC to tune with? Is that going to mess with anything like the linear movement of the fuel pressure the engine is used to? I've only tried tuning once with a 2G MAS, but had some 550cc injectors to work with. I'm not worried about running out of fuel or anything since I'm only running 10psi on the 14b right now. I'll bump it to 16psi or so when things are working right. Any advice would be great.
First off i don't see how you aren't hitting fuel cut.. If you are putting +30% on the afc you should be hitting fuel cut. Put the fuel pressure back to 43psi (vacuum line off). Then check for boost leaks. Wacky fuel trims are usually boost leaks..

[iamtall77]

I don't have any known boost leaks. I'll check again since I haven't done one since I got everything running. Right now I'm looking into my timing. I get around 30+ degrees at idle and it's idling really high right now. The CAS is set at full retard and I'm still getting really advanced timing. I'm sure I just got in a rush and put the CAS 180 out.

My +30% on the SAFC is on the low setting. I should need to add around 20% my stock 450cc injectors and the 2G MAS combo. At least that's what I remember from my first 2G MAS swap. I'll check my CAS, check for boost leaks and then reduce the fuel pressure back to stock. I didn't want to bump the pressure up anyway, I just thought it was a start to help find my issue.

[burnett03]

What will solve your problems is verifying the base fuel pressure, verifying the base timing, (timing light and grounding the timing wire) and then getting the fuel trims in line.