Can ANYthing in the tune alter fueling on one side of the motor only?
07-16-2009, 12:31 AM
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Can ANYthing in the tune alter fueling on one side of the motor only? Is it possible for SOMEthing in the tune to cause the car to go intermittently lean on ONE side of the motor only???
I'm using the factory OS MAF tuned with 36 lb injectors, brand new racetronics pump, etc.
The lean condition usually occurs at light throttle, less than 12%, cruising from 2000-2600 rpm's.
BUT it doesn't happen all the time OR even often at all. My shop didn't notice the spike yet but I told them to take it out for a steady cruise o the highway and it should show up.
They already checked for leaks by the O2 sensor on the drivers-side of the Kooks 1 7/8-2" headers (it goes lean on the drivers side only)
When the incident occurs, the passenger side will read -6.x lterms while the drivers side will go +25%. Obviously the car will begin to stumble and backfire form all the fuel being dumped in. My wideband will shoot to 17 af at this time.
They checked the fuel pressure at the rails; perfectly fine.
Any suggestions?????
I'm using the factory OS MAF tuned with 36 lb injectors, brand new racetronics pump, etc.
The lean condition usually occurs at light throttle, less than 12%, cruising from 2000-2600 rpm's.
BUT it doesn't happen all the time OR even often at all. My shop didn't notice the spike yet but I told them to take it out for a steady cruise o the highway and it should show up.
They already checked for leaks by the O2 sensor on the drivers-side of the Kooks 1 7/8-2" headers (it goes lean on the drivers side only)
When the incident occurs, the passenger side will read -6.x lterms while the drivers side will go +25%. Obviously the car will begin to stumble and backfire form all the fuel being dumped in. My wideband will shoot to 17 af at this time.
They checked the fuel pressure at the rails; perfectly fine.
Any suggestions?????
07-16-2009, 01:28 AM
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What could cause the low-rpm, light-throttle misses?
They are not present at WOT ...
JonCR96Z: I'll post the log tomorrow. I'll also tell the shop to swap the sensors from side to side and put new ones in if that's the case.
They are not present at WOT ...
JonCR96Z: I'll post the log tomorrow. I'll also tell the shop to swap the sensors from side to side and put new ones in if that's the case.
07-16-2009, 02:34 AM
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I'm fairly certain Frost is correct in his analysis and that the CRAP MSD coils on my car may be failing; causing the low rpm miss.
I expected them to last more than 75k miles. Stock or truck coils are going in if my suspicions are correct.
I expected them to last more than 75k miles. Stock or truck coils are going in if my suspicions are correct.
07-16-2009, 12:04 PM
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07-17-2009, 06:39 AM
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They dropped my car off at my house last night and I'll be logging it tonight after work. My mechs put a stock set of coils on (I already replaced the plugs and wires last month when this issue arose).
Pump is new. If the problem still exists; injectors would be the likely culprit at this point simply by process of elimination.
My mechanic drove my car at LEAST 50 miles and noticed no stumbling or lean spikes; so my fingers are crossed
I'll report back sat morning
Pump is new. If the problem still exists; injectors would be the likely culprit at this point simply by process of elimination.
My mechanic drove my car at LEAST 50 miles and noticed no stumbling or lean spikes; so my fingers are crossed
I'll report back sat morning
