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Need a little help here. Our Supra is breaking up in the upper RPMs. When on the dyno it showed that it was going stupid rich during this time. We ended up correcting out ~-33% on the SAFC to get it to run properly, and this is on stock injectors.
A little history -
Car ran great. 112 MPH traps on 100 octane and ~18 PSI. We wanted to fine tune her a little more so we purchased the SAFC. We had the SAFC installed (at the time I was too afraid of messing something up doing it myself) and put the car on the dyno to get a few more RWHP. The car immediately began breaking up in the high RPMs. It was fine prior to the SAFC install, however.
We made numerous pulls on the dyno and finally got it to stop breaking up, but as noted above, that was with a ~-33% correction. Car made terrible power once the stuttering stopped.
We assumed at this point that maybe the SAFC was bad / hooked up wrong. So, to test the theory we pulled the SAFC out of the car totally. It still broke up in the upper RPMs.
My only guess at this point is maybe the airflow signal from the MAS is not getting to the ECU cleanly thanks to the snip, splice, and then patch job that has been done to the wire going to the ECU. Does this sound reasonable??? What would be the symptoms of a car running without an air flow signal or with a poor signal? Shouldn't it throw a CEL if that were the case? I'm going to be going back in this weekend to see if I can't get a better connection for the air signal wire, and I'm open to any suggestions you guys can offer to point me in the right direction.
We have done a boost leak test, and the system holds fine, with a small leak around the EGR that we plan on taking care of. Other than that, it's pretty much solid.
Thanks for any help you guys can offer.
A little history -
Car ran great. 112 MPH traps on 100 octane and ~18 PSI. We wanted to fine tune her a little more so we purchased the SAFC. We had the SAFC installed (at the time I was too afraid of messing something up doing it myself) and put the car on the dyno to get a few more RWHP. The car immediately began breaking up in the high RPMs. It was fine prior to the SAFC install, however.
We made numerous pulls on the dyno and finally got it to stop breaking up, but as noted above, that was with a ~-33% correction. Car made terrible power once the stuttering stopped.
We assumed at this point that maybe the SAFC was bad / hooked up wrong. So, to test the theory we pulled the SAFC out of the car totally. It still broke up in the upper RPMs.
My only guess at this point is maybe the airflow signal from the MAS is not getting to the ECU cleanly thanks to the snip, splice, and then patch job that has been done to the wire going to the ECU. Does this sound reasonable??? What would be the symptoms of a car running without an air flow signal or with a poor signal? Shouldn't it throw a CEL if that were the case? I'm going to be going back in this weekend to see if I can't get a better connection for the air signal wire, and I'm open to any suggestions you guys can offer to point me in the right direction.
We have done a boost leak test, and the system holds fine, with a small leak around the EGR that we plan on taking care of. Other than that, it's pretty much solid.
Thanks for any help you guys can offer.