wideband o2 questions.
#23
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I'm not an expert on that, but there are some articles on the forum about "burping" the cooling system. As I recall, it involves parking such that the front end is up at a pretty steep angle, removing the radiator cap, and running the engine until the thermostat opens, adding coolant as necessary.
#24
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Ok I'm changing the radiator today since I broke the top by laying on it when I was changing the temp sensor so when I fill it up I will find a hill and see what that does.
#25
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So I guess I am going to fight trying to get this thing bleed out cuz I put it on the biggest hill I could find and had the cap off and it still gurgles a little not as bad but I guess it's just going to take a couple trys to get it bleed unless I undo the temp sensor and let the air out of it.
#26
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I have the same issue, it will take a few tries.
Run the engine, rev the engine a bit while on the hill, let it sit on the hill, and cool down. add more coolant.
I just jack it up in my driveway, you want the rad cap to be the highest point.
Run the engine, rev the engine a bit while on the hill, let it sit on the hill, and cool down. add more coolant.
I just jack it up in my driveway, you want the rad cap to be the highest point.
#27
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Yea I figured I would have to do it a couple tries. I revved it up on the hill I was on and it still wasn't enough but I will get it eventually.
#28
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Ok so I'm testing my afm driving and at idle at ot it reads 4.5 and just giving enough gas to keep my speed up on a straight away it's reading 7.5 volts. Keep in mind I'm running a 7mge vafm.
#29
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So how are you measuring the VAFM? Do you have a probe stuck in the connector on the VS terminal that you are monitoring while driving? Is the other side of your meter connected to a good ground, or did you possibly connect it to +12V?
The VS terminal should be at 4.5 volts with the air flow vane fully closed, and lower voltage when it is open. I suspect you are measuring with respect to +12V, or some voltage around 9V, rather than ground. The ECU is a +5 volt system, and it does not expect voltages higher than that from sensors.
Edited: My previous comments in this post were with respect to the TPS, not the VAFM. Sorry.
The VS terminal should be at 4.5 volts with the air flow vane fully closed, and lower voltage when it is open. I suspect you are measuring with respect to +12V, or some voltage around 9V, rather than ground. The ECU is a +5 volt system, and it does not expect voltages higher than that from sensors.
Edited: My previous comments in this post were with respect to the TPS, not the VAFM. Sorry.
Last edited by RJR; 02-25-2015 at 04:03 PM.
#30
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I am measuring the + voltage coming out of vf1 terminal from a wire to the inside of my truck. If I turn it to rich it more it makes my engine bog down when it drops rpm at idle to 200 rpm then back to idle every time I rev it up.
#32
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No I just ran a wire into the connector and ran threw the firewall where I can put a volt meter on that wire so I can drive and see what it's reading. It's just a loose wire from a roll or wire I had. I wish I could upload a pick but it keep a saying that the picture size is too big.
#33
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I have to get out of my truck open the arm and turn it a couple clicks and get back in the truck and drive. This picture that isn't too big to upload is the way I'm turning it. I got the pic from yotatech about a year ago.
#36
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Well, you shouldn't be getting 7.5 volts on the VF1 terminal under any circumstances. +5V is the maximum you should see. Something is not right in your setup; likely you don't have the low side of your meter grounded properly. Fix that first and then take some more measurements. Go back to my first post to see what the voltages on VF1 mean once you get your measurement process figured out.
#37
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I really truly appreciate you helping me with this but all jokes aside I am doing everything your post states and I'm just posting what I am seeing. I have a good ground on a bolt in the body
#38
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Honestly, I'm not joking or poking fun; just pointing out what the most likely sources of error might be. As I mentioned earlier, the ECU is a 5V system (standard CMOS/TTL logic from back in the 80's) and I'm pretty sure it should not be putting 7.5 volts on the VF1 pin. You should be seeing the voltage move in 5 steps; 0V, 1.25V, 2.5V, 3.75V, and 5V. Since you have the meter properly grounded, I can't really figure out an explanation for what you're seeing, other than something is not wired right between the ECU and the diag connector.
I'll double check those voltages when I get a chance. Maybe I'm mis-remembering something. Also, what year truck do you have? Mine's a '94; if yours is '91 or older things might be a little different.
I'll double check those voltages when I get a chance. Maybe I'm mis-remembering something. Also, what year truck do you have? Mine's a '94; if yours is '91 or older things might be a little different.
Last edited by RJR; 02-25-2015 at 06:52 PM.
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