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My SVT has trouble starting when it has been sitting for a long time, and runs bad at idle for like 2 min or until I go and reach like 3000 rpm. If I just started it and I give it some gas, sometimes the rpms even drop and it wants to die... When the problem began around 1 month ago I removed the MAF and cleaned it with contact cleaner, seemed to help a little at first but finally it didn't solve anything. I also unpluggued and repluggued all the sensors I could in the engine bay. Thinking it's probably a clogged fuel filter, I bought a new one and will install it today.

I did some datalogging with my Predator this morning and the fuel rail pressure is stable at 40 psi, so I doubt the fuel filter will improve anything. The MAF reads around 0.8V at idle (950 rpm), is that what it should be reading? What else can I look for?
 

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Thats weird, same thing happend in my Friends Camaro. We cleaned it with that CRC stuff and a week or two later, Same symptoms as yours. We changed the fuel filter, still same prob. We went to the Pik/n/pull got a new(old) maf.
installed it,Voila no stumbling or dying out, everything was ok.

I think you need a new maf-
 

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Discussion Starter #3
Any ideas?
 

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You need a new Maf sensor.
-MAF V PID (MAF PID) reading less than 4.6 volts (Refer to equivalent grams/second chart in GO to Pinpoint Test DC ) in continuous memory or key ON and engine running indicates a hard fault.
 

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Discussion Starter #5
You need a new Maf sensor.
-MAF V PID (MAF PID) reading less than 4.6 volts (Refer to equivalent grams/second chart in GO to Pinpoint Test DC ) in continuous memory or key ON and engine running indicates a hard fault.
Not sure I get what you're saying, the MAF should read 4.6V or more on idle? That doesn't make sense to me, its range is 0 to 5 V and voltage is proportional to airflow??
 

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Not sure I get what you're saying, the MAF should read 4.6V or more on idle? That doesn't make sense to me, its range is 0 to 5 V and voltage is proportional to airflow??
I just quoted someone from FJ on this.
 

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Discussion Starter #11
I cleared the ecu a ton of times and it doesn't help anything. Also changed the fuel filter. I'm getting new spark plugs this weekend, I think they have 60k on them. I'll get Taylor wires and gap them at 0.060. If that doesn't solve the problem I'll check for a MAF and both O2 sensors...
 

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^^ good luck with the taylor wires. i ordered mine from summit racing but looked everywhere for them. no one has them in stock, they get made to order. i just got a postcard from summitracing saying that they're not even due to ship from there till june 14th!! [rant] when i ordered them online it said they'd ship by the 8th.

i'm having the same problem you are btw
 

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.86 volts at idle is fine.

What is the TPS voltage at idle?
 

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Discussion Starter #14
I'll try to get TPS readings this weekend. I guess that sensor could also be the cause...
 

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yeah i was going to say the same thing a MAF should operate between .5v-4.7v. It should never read less than .5 at idle and never more than 4.7v at wide open throttle. if it is maxed on either end 0v or 5v there may be a problem.
 

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My SVT has trouble starting when it has been sitting for a long time, and runs bad at idle for like 2 min or until I go and reach like 3000 rpm. If I just started it and I give it some gas, sometimes the rpms even drop and it wants to die... When the problem began around 1 month ago I removed the MAF and cleaned it with contact cleaner, seemed to help a little at first but finally it didn't solve anything. I also unpluggued and repluggued all the sensors I could in the engine bay. Thinking it's probably a clogged fuel filter, I bought a new one and will install it today.

I did some datalogging with my Predator this morning and the fuel rail pressure is stable at 40 psi, so I doubt the fuel filter will improve anything. The MAF reads around 0.8V at idle (950 rpm), is that what it should be reading? What else can I look for?
The voltage at idle is ok at 0.8V and it should read 4,3V (fluctuating) on brief accelaration.

SPEED IS LIFE
 

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Discussion Starter #17
Ok just found out that the unstable idle after starting is a lot worse when the A/C compressor is running (fan at windshield position). But it wasn't doing this before and it still starts badly. The fact that I can give it some gas and the rpms drop also tells there's a problem.
 

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My SVT has trouble starting when it has been sitting for a long time, and runs bad at idle for like 2 min or until I go and reach like 3000 rpm. If I just started it and I give it some gas, sometimes the rpms even drop and it wants to die... When the problem began around 1 month ago I removed the MAF and cleaned it with contact cleaner, seemed to help a little at first but finally it didn't solve anything. I also unpluggued and repluggued all the sensors I could in the engine bay. Thinking it's probably a clogged fuel filter, I bought a new one and will install it today.

I did some datalogging with my Predator this morning and the fuel rail pressure is stable at 40 psi, so I doubt the fuel filter will improve anything. The MAF reads around 0.8V at idle (950 rpm), is that what it should be reading? What else can I look for?
I have a 04 SE AND my egr had to get cleaned and evap purge got replaced
 
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