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Tuning Problem?

 
Old 07-26-2010, 02:14 PM
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Adam Poland
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Default Tuning Problem?

My car has a weird problem. When its cold it runs fine when you start off at a red light, stop sign, etc. The same when it's hot. But in between, when starting off from a red light, it will spit and sputter and barely move. After about 30 seconds of that, it drives fine for the rest of the trip. It happens every time I drive it. The wideband reads about 10.9-11.6 when this happens.
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Old 07-26-2010, 02:55 PM
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IMB951
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Do you have a MAF? Might want to check on your low rpm voltage readings with whatever software you tuned it with. It could be getting too much fuel at low rpm's.

Also check your temps when that happens. On a hot day my 951 will be sluggish from a stoplight if it's idling too long with the waterpump thermostat open and the fans kicked on. Heat soaked intercooler + intake = pitifully slow launch. We all need to vent our hoods!

Last edited by IMB951; 07-26-2010 at 03:20 PM.
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Old 07-26-2010, 03:56 PM
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Adam Poland
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Hmm, I'll have to do that I guess. Im thinking it may be heat. Does your car spit and sputter and you have to motion to people to go around you? I do that, and as soon as they get by me, my car kicks in and I'm gone. It makes people pretty mad...
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Old 07-26-2010, 04:02 PM
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No spitting and sputtering, mine's just sluggish and I can "feel" the heat soak dissipate through the engine until I'm at speed. Your issue sounds fuel related on top of the heat.
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Old 07-26-2010, 04:21 PM
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It sounds too me like you might be running really rich. The heat won't make it sputter. The heat just makes it SLLLOOOWWWW!
If you know that the AFR's are good, then check the TPS.
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Old 07-26-2010, 05:45 PM
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Yeah I've thought about the tps too. The weird part is that it only happens once every trip. But, it is a 951, so anything is possible lol.
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Old 07-26-2010, 07:54 PM
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1) What is your engine setup?
2) How are you tuning?

IIRC weren't you wondering about tuning via FPR a while back? Could have been someone else....

Also, did Lindsey recommend the 55lb injectors for the Super 53? and on a side note, is your turbo dry or wet? 360 or DBB? Need more details on the rest of the setup before we can recommend a path forward....
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Old 07-26-2010, 11:29 PM
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I'm using the DBX software to tune. My Power Perfect got shorted out. Lindsey did reccomend the 55's for the Super 53. The turbo is dry, 360.
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Old 07-26-2010, 11:41 PM
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Could be electrical? Plugs, Cap, rotors...perhaps?
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Old 07-27-2010, 12:18 AM
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Almost sounds like the engine temp sensor is on its way out.
When cold, your engine starts and runs; same when your engine is fully warmed up.
But in the transitional phase, it's giving the DME a false reading; probably slow to register that the engine is warming up (DME thinks the engine is still colder than it actually is, making it rich)
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Old 07-27-2010, 12:38 AM
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What chip?
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Old 07-27-2010, 01:04 AM
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What chips are you running for the 55lb injectors? I have the DBX85 for my 951 non-S and it works great, but I am running stock injectors with the 951MAX chips.
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Old 07-27-2010, 02:55 PM
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Ive got the 951 max chips for the injectors
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Old 07-27-2010, 10:42 PM
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Are the chips for the MAF?
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Old 07-27-2010, 11:47 PM
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Yes they are.
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