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Old 01-19-2009, 12:49 AM   #1
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Default another prob with the NB

Man im sorry for all the threads but this NB is kicking my ***. After i sorted out the issue with the CAS i got the car started. The issue im having with the car is it wont hold afr's correctly. first time seeing this, Ive install MS on a few NA with out a prob. Im guessing something is wrong with the fuel system on the car or something. I load my msq file from my daily( NA, turbo, 550cc ect ) expecting to have the car drivable and it runs like crap. So i figure i will adjust.. i make adjustments to the table its fine for a second then goes too lean or rich depending on what i did. This prob has been going on for a while with other management in the car. The owner had exede on it before and said he could never get it to run right no matter what he did to the fuel table. The car still has the EGR system still in would that effect anything? Also never messed with a return less fuel system, do you think that would have to do anything with it?
The injectors are 550 and they fresh and checked.

Im lost if anyone has suggestions shoot im all ears
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Old 01-19-2009, 01:01 AM   #2
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Man im sorry for all the threads but this NB is kicking my ***. After i sorted out the issue with the CAS i got the car started. The issue im having with the car is it wont hold afr's correctly. first time seeing this, Ive install MS on a few NA with out a prob. Im guessing something is wrong with the fuel system on the car or something. I load my msq file from my daily( NA, turbo, 550cc ect ) expecting to have the car drivable and it runs like crap. So i figure i will adjust.. i make adjustments to the table its fine for a second then goes too lean or rich depending on what i did. This prob has been going on for a while with other management in the car. The owner had exede on it before and said he could never get it to run right no matter what he did to the fuel table. The car still has the EGR system still in would that effect anything? Also never messed with a return less fuel system, do you think that would have to do anything with it?
The injectors are 550 and they fresh and checked.

Im lost if anyone has suggestions shoot im all ears
Post the msq that you're running on the nb and I'll have a look. You can attach it.

Does it run fair? Driveable? Do AFR's ever get stable? What kind of AFRs are you getting?
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Old 01-19-2009, 02:09 AM   #3
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Ill log it tomorrow when i go to work and post it. Its hardly drivable. one min its at a good afr when adjusted. Then afr goes to **** with the same valued just entered..
Attached Files
File Type: msq 1-3-09 street 6-7lbshighres.msq (35.2 KB, 65 views)
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Old 01-19-2009, 12:40 PM   #4
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msq looks good. I'd double check the ignition input circuit settings as I'm not familiar with those. You mention it had fuel problems before installing MS. That's probably the problem. Again, a datalog will help. Yall have the map line hooked up, right? Also you could answer the questions I already asked. Might help.
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Old 01-19-2009, 02:01 PM   #5
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Here is the log from this morning drive to work.

When looking at it i tried to keep a steady kpa on the highway and you see the afr's change with the same load. The duty cycle has not change also.

There are two things that im thinking

1- That im getting irregular fuel pressure (returnless system)
2- EGR malfunction and exhaust gases interrupting with tune

but im leaning more with the first one.....
any ideas?
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File Type: xls datalog200801242147.xls (898.0 KB, 72 views)
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Old 01-19-2009, 02:16 PM   #6
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Could be a dying fuel pump. But you do have other problems. You have a lot of noise. The CLT reading is all bouncy. So is the TPS signal. The TPS signal being noisy will cause TPS based acceleration enrichments to come on. Try turning those off and see if it gets better. You still have to figure out what's causing the noise and fix it though.

Where is the vacuum line hooked to on the intake manifold? What size vac line?
How is everything wired up?
What wideband and how's it wired up?
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