cold starts fixed
- Thread starter noslow1986
- Start date
Dumping the codes will normally show a faulty sensor. The ACT & ECT may be on the outer limits and not set a code but cause problems. Use a DVM or multimeter to check them.
Pin 25 ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.
Pin 7 ECT signal in. at 176 degrees F it should be .80 volts
The ACT & ECT have the same thermistor, so the table values are the same.
Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.
Voltages are measured across the two connector pins of the sensor with the sensor connected. Some safety pins used to probe the connector from the rear will be helpful
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61
Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms
Pin 25 ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.
Pin 7 ECT signal in. at 176 degrees F it should be .80 volts
The ACT & ECT have the same thermistor, so the table values are the same.
Here's the table: The values are +/- 15%, so don't get worried if your readings vary a little bit.
Voltages are measured across the two connector pins of the sensor with the sensor connected. Some safety pins used to probe the connector from the rear will be helpful
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61
Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms
nevermine still having problem runs a little better. but my intake gasket is still wet in the back could this be a problem if my fuel pressure reg is leaking into the intake alot. i got 35 psi while running but that gasket might be junk. ran great with the the stock one unplug, got a new one and runs ****ty. can i leave it unpluged
I'm not able to keep up with you,
What is new? and now unplugged?
If you have fuel pooling on the intake, then that needs to be the first issue resolved. That is a safety hazard.
Is is fuel? Maybe oil?
Is there fuel in the vac line off the regulator?
jason
i tried to take off the intake but i couldnt get the last bolt in the back, so i pried it up and could smell the gas i pretty sure its gas. as far as as ect sensor i unplug mine and ran perfect no idle problem no cold starts. then i went and got a new one, hook it up and ran like ****. is it safe to run ect sensor without the harness hook up,even the new one unpluged ran ****ty
When you unplug an EFI sensor you send the ecu into a 'limp mode'
The limp mode is a crappy way of running the car, as several strategies are ignored.
Just because the car runs differently with the sensor unplugged, does not mean that there is something wrong with the sensor. This applies to ALL sensors.
Find out why you are having problems, and make the appropriate changes.
Step one is to pull the codes...
Here is a summary chart for how the ecu reacts to out of range sensors (straight from the GUFB).
jason
The limp mode is a crappy way of running the car, as several strategies are ignored.
Just because the car runs differently with the sensor unplugged, does not mean that there is something wrong with the sensor. This applies to ALL sensors.
Find out why you are having problems, and make the appropriate changes.
Step one is to pull the codes...
Here is a summary chart for how the ecu reacts to out of range sensors (straight from the GUFB).
jason
You couldn't get the bolt out, so you pried the intake up with the bolt still in place? You're kidding, right? You're gonna break something and the car will really run like crap then. Take your time and you should be able to get to all of the bolts using a variety of extensions, methods. The last thing you wanna do is pry the intake up and either snap the bolt or break the intake. No one is trying to be rude or yell at you, but there are a few things that are fundamental that it's helpful to understand or you'll cost yourself a bunch of money, frustration, and broken/damaged parts.
If the intake gasket is wet, can you tell for sure it's fuel? Is it the upper or lower intake gasket you speak of? I really don't see how the intake gasket would be wet w/ fuel. If the fuel is going to the intake from the fuel pressure reg. via the vac line, my assumption is that the fuel would go down to the heads.
Are you sure it's not a leaking injector or fuel rail causing the fuel smell? Do you have an aftermarket Mass Air Flow sensor (MAF) and/or non-stock fuel injectors?
What's weird is that w/ the ECT sensor unhooked and the computer in limp mode, it should run a little rich, which I would think would cause a fuel smell, not eliminate one.
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