fuel pressure decreased two datalogs

[9queSt]

One datalog is from may and the other is from a week ago. Back in may my fuel pressure gauge was reading 70psi at idle. It now reads 60psi. Before I go and crank up the regulator Im looking for opinions. Looks like the afr did in deed lean up a bit.

What do you think??

[jromero2002]

It leaned up everywhere. Glad you got the launch to 10psi.
If you tuned @70psi make sure you always run the car @70psi.
Keep an eye on fuel pressure you may have a regulator or fuel pump quitting on you if you have to keep raising the pressure to hit 70psi.

[9queSt]

It leaned up everywhere. Glad you got the launch to 10psi.
If you tuned @70psi make sure you always run the car @70psi.
Keep an eye on fuel pressure you may have a regulator or fuel pump quitting on you if you have to keep raising the pressure to hit 70psi.

I will keep an eye on it. thank you

I made some changes with the perameters....fuel compensation.....air temp comp....idle and light engine load...... I change this from 0 to -25 because the car was idleing way to rich. Do you think that would cause afr to be leaner at wot like were seeing??

I also changed the post start fuel adjustment from -30 to 0. I wouldn't think that would effect WOT???

[jun1or]

It leaned up everywhere. Glad you got the launch to 10psi.
If you tuned @70psi make sure you always run the car @70psi.
Keep an eye on fuel pressure you may have a regulator or fuel pump quitting on you if you have to keep raising the pressure to hit 70psi.

I will keep an eye on it. thank you

I made some changes with the perameters....fuel compensation.....air temp comp....idle and light engine load...... I change this from 0 to -25 because the car was idleing way to rich. Do you think that would cause afr to be leaner at wot like were seeing??

I also changed the post start fuel adjustment from -30 to 0. I wouldn't think that would effect WOT???

Air temp compensation tables (light load) have no affect on WOT runs. Instead of changing this table, adjust the low cam fuel table to maintain idle.

1.) Has part throttle tuning been done at all? It may not have been touched up by the tuner if this is a 1320 queen (drag car for you non-us readers).
2.) Are you running 100% open loop? Appears so as I don't see any s.trims and l.trims when getting up to the line.
3.) What are your target AFR's at full load?

Regardless I agree with the above comments about fuel pressure. You could be chasing your tail if it's fuel pressure related. I really wish there was a way to use an electronic fuel pressure gauge (5v?) output as an input to s300 and overlay on the graphs. Maybe there is, I don't know. I would die for this feature in FlashPro right now. Hell any aux inputs would be great. Anyway...

Couple things I noticed. Your datalog 1700supra.s3d - appears the car is not up to temps during that run. I don't see any ECT.c values however, meaning extra fuel doesn't appear to be dumped in due to coolant temp comp table, but might want to keep an eye on it.

On the file 920gtr.s3d - I still think you could benefit from boost by gear by rpm here in second. Take a look at timestamp 1:15 for instance. I doubt you're close to spinning 2nd from 5300-7000rpms, so why not ramp up pwm duty cycle to 40% at 5000, down to 25% at 7000rpm and see if she holds (holds the track AND boost levels tapering down as requested).

Good luck,

Mike

[9queSt]

It leaned up everywhere. Glad you got the launch to 10psi.
If you tuned @70psi make sure you always run the car @70psi.
Keep an eye on fuel pressure you may have a regulator or fuel pump quitting on you if you have to keep raising the pressure to hit 70psi.

I will keep an eye on it. thank you

I made some changes with the perameters....fuel compensation.....air temp comp....idle and light engine load...... I change this from 0 to -25 because the car was idleing way to rich. Do you think that would cause afr to be leaner at wot like were seeing??

I also changed the post start fuel adjustment from -30 to 0. I wouldn't think that would effect WOT???

Air temp compensation tables (light load) have no affect on WOT runs. Instead of changing this table, adjust the low cam fuel table to maintain idle.

1.) Has part throttle tuning been done at all? It may not have been touched up by the tuner if this is a 1320 queen (drag car for you non-us readers).
2.) Are you running 100% open loop? Appears so as I don't see any s.trims and l.trims when getting up to the line.
3.) What are your target AFR's at full load?

Regardless I agree with the above comments about fuel pressure. You could be chasing your tail if it's fuel pressure related. I really wish there was a way to use an electronic fuel pressure gauge (5v?) output as an input to s300 and overlay on the graphs. Maybe there is, I don't know. I would die for this feature in FlashPro right now. Hell any aux inputs would be great. Anyway...

Couple things I noticed. Your datalog 1700supra.s3d - appears the car is not up to temps during that run. I don't see any ECT.c values however, meaning extra fuel doesn't appear to be dumped in due to coolant temp comp table, but might want to keep an eye on it.

On the file 920gtr.s3d - I still think you could benefit from boost by gear by rpm here in second. Take a look at timestamp 1:15 for instance. I doubt you're close to spinning 2nd from 5300-7000rpms, so why not ramp up pwm duty cycle to 40% at 5000, down to 25% at 7000rpm and see if she holds (holds the track AND boost levels tapering down as requested).

Good luck,

Mike

I think the tuner did a little part throttle tuning on the dyno. But your right its a 1320 queen. Maybe I should run part throttle in clossed loop.

It is in open loop. I couldn't get clossed loop to work. But Im going to try again once I put the trans back in the car on monday. (the trans got new synchros.)

target afr are 10.8 at WOT

Once I get to the track im going to try ramping up the pwm at 5000. Ill let you know.

Im going to get a 5v fuel pressure sensor for next year.

1700supra. Should fuel be added when the ect is at cooler? Speedfactory just told me to run the car at 170*f ect when launching.