what would cause....
06-19-2005, 10:32 PM
#1
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Location: Bedford, TX
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what would cause....
my car sometimes wont start but when i floor it, it will start to run and then die. if i do this a couple of times them it will start. any ideas?? i can smell lots of gas when i do it too.
06-19-2005, 11:46 PM
#2
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Re: what would cause....
Holding the throttle to the floor puts the PCM in "clear flood" mode. Sounds like you may have a leaky injector or two that is flooding the cylinders when you shut off the engine.
Another possibility would be a coolant temp sensor that is showing too low a temperature, and causing the PCM to set an overly rich cold start A/F ratio.
Another possibility would be a coolant temp sensor that is showing too low a temperature, and causing the PCM to set an overly rich cold start A/F ratio.
06-20-2005, 05:33 PM
#5
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Location: San Antonio Texas
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Re: what would cause....
Pull the vaccuum line off of the Fuel regulator, it "should" be dry, if it is wet, or smells of gas, your regulator is bad, and leaking fuel back to the intake, and flooding you out.
While the motor is cool,
Take the four bolts out of the fuel rails, gently lift the fuel rail, and injectors out of the intake, the injectors should be dry, if not, note which ones are wet, and those are leaking. While the fuel rail is pulled out, you can turn the key to the "on" position, let the pump cycle, and then look for leaky injectors.
I do not think that the IAT sensor would cause it to flood out. It will richen it up, but not flood it out.
Good Luck
While the motor is cool,
Take the four bolts out of the fuel rails, gently lift the fuel rail, and injectors out of the intake, the injectors should be dry, if not, note which ones are wet, and those are leaking. While the fuel rail is pulled out, you can turn the key to the "on" position, let the pump cycle, and then look for leaky injectors.
I do not think that the IAT sensor would cause it to flood out. It will richen it up, but not flood it out.
Good Luck
06-20-2005, 10:00 PM
#6
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Re: what would cause....
i scaned with datamaster and i have 2 DTC's 16 and the MAF code forgot the # for it. 16 is low sig? does that mean opti is bad. the maf code is when i unplugged it to try speed density mode. how do i erase it? thanks guys
nick
nick
06-20-2005, 10:20 PM
#7
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Location: San Antonio Texas
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Re: what would cause....
to reset the DTC's:
while in datamaster, on the window where you select Record, Start, STop, etc, there should be a button that says "reset DTC" or something similar. You can not do this while you are recording however, you click on stop first.
16- does it say "Low Res. Sig"? Mean Low resolution signal from OPTI. Could be dirty since it is simply an optical sensore looking at small slots in a disc. May be possible to take apart and clean with alcohol.
good luck
while in datamaster, on the window where you select Record, Start, STop, etc, there should be a button that says "reset DTC" or something similar. You can not do this while you are recording however, you click on stop first.
16- does it say "Low Res. Sig"? Mean Low resolution signal from OPTI. Could be dirty since it is simply an optical sensore looking at small slots in a disc. May be possible to take apart and clean with alcohol.
good luck
06-20-2005, 10:24 PM
#8
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Re: what would cause....
i guess that i will try that. thanks alot. 16 code could only be the opti right? also when i am running datamaster the graph at the bottom with the 4 different colors every once in a while the red line(RPM) will just jump up and the other lines stay the same. when you give the car gas all the lines move. buy only the rpm jumps up about halfway up. does this mean that it is the opit reading incorrectly? thanks again
nick
nick
06-20-2005, 10:42 PM
#9
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Location: San Antonio Texas
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Re: what would cause....
normally, the rpm will bounce around 25 rpm or so. I think datamaster only displays 25 rpm increments.
I do not remember exactly what the high and low resolution inputs are used for. Step one would be check and cleam all the connections. could probably find that on line .
Has anyone done any tuning to the car, or tampering with the computer?
I do not remember exactly what the high and low resolution inputs are used for. Step one would be check and cleam all the connections. could probably find that on line .
Has anyone done any tuning to the car, or tampering with the computer?
06-21-2005, 10:20 AM
#10
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Location: Hell was full so they sent me to NJ
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Re: what would cause....
If you have DTC 16, and the engine is running, its a "stored" code. The PCM needs the low resolution pulse pattern to know when to fire the fuel injectors in the correct sequence. If it can't "see" the low res pulse (DTC 16 "active") it will shut down the fuel pump and injectors.
It isn't unusual to see DTC 16 as a stored code... seems like the PCM has a problem occasionally finding the pulse pattern at stratup. If you get it often, it likely a problem with the optical sensor or the wiring harness. Clear the code and see how soon it comes back. See if you can correlate the "blip" on the RPM to the return of DTC 16.
As a first step, check the Opti harness connectors (the one on the Opti and the gray one on the passenger side of the intake manifold) for corrosion.
The low res pulse tells the PCM which cylinders are approaching TDC on the compression stroke. The high res pulse simply provides additional data over the interval between the 8 low res pulses so that the PCM can know whether the rotational velocity of the crank is changing, so that it can more accurately fire the plug.
It isn't unusual to see DTC 16 as a stored code... seems like the PCM has a problem occasionally finding the pulse pattern at stratup. If you get it often, it likely a problem with the optical sensor or the wiring harness. Clear the code and see how soon it comes back. See if you can correlate the "blip" on the RPM to the return of DTC 16.
As a first step, check the Opti harness connectors (the one on the Opti and the gray one on the passenger side of the intake manifold) for corrosion.
The low res pulse tells the PCM which cylinders are approaching TDC on the compression stroke. The high res pulse simply provides additional data over the interval between the 8 low res pulses so that the PCM can know whether the rotational velocity of the crank is changing, so that it can more accurately fire the plug.
Last edited by Injuneer; 06-21-2005 at 10:23 AM.
06-21-2005, 11:13 AM
#11
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Re: what would cause....
ok i mess again with it tonight. the RPM jumps way up when i say it jumps. like amost an inch on the graph???? if some one wants too look at the datamaster file i can email it tonight. thanks for the help though guys