Need help with diagnosing a high idle
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Need help with diagnosing a high idle I have HP tuners and today is the first day I can actually fire the engine and use it.
I'm getting a high 1600 idle at cold start, I figured out how to do a real time scan so could someone help me out and see if there is something out of wack that could be causing this high idle?
I checked for vacuum leaks and replaced the intake gaskets with no change
My PCM is supposed to have a 2004 express Van tune, modified to work with my 2004 5.3 truck engine modified to DBC. The PCM is from a 2004 express Van and base tune done by lt1swap.com
Here are the details on the motor
Stock 5.3 Cast iron block from a 2004 Silverado, with all stock sensors that came on this engine
modified 2004 harness that came with this engine
2004 Express Van PCM with the correct wiring added for the cable throttle body
LS1 intake with the stock DBC throttle body, Map and 350 injectors
Custom Air intake with the MAF from the 5.3 truck engine
Rear O2 delete
I'm getting a high 1600 idle at cold start, I figured out how to do a real time scan so could someone help me out and see if there is something out of wack that could be causing this high idle?
I checked for vacuum leaks and replaced the intake gaskets with no change
My PCM is supposed to have a 2004 express Van tune, modified to work with my 2004 5.3 truck engine modified to DBC. The PCM is from a 2004 express Van and base tune done by lt1swap.com
Here are the details on the motor
Stock 5.3 Cast iron block from a 2004 Silverado, with all stock sensors that came on this engine
modified 2004 harness that came with this engine
2004 Express Van PCM with the correct wiring added for the cable throttle body
LS1 intake with the stock DBC throttle body, Map and 350 injectors
Custom Air intake with the MAF from the 5.3 truck engine
Rear O2 delete
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I'm using a TPS sensor for a 2004 express Van on a LS1 throttle body. I know the sensors are different between those models but would it mount the same on either one?
Here's my engine info BTW
Here's my engine info BTW
Do you have a PCV system hooked up. The truck PCV system is not directly compatible with a LS1 intake. Did you modify it to work with the car intake? Do you have a full exhaust system hooked up? At around 30 seconds into the scan the passenger side O2 starts indicating that bank 2 is extremely lean. A log of it fully warmed up would be better. It hasn't gone or tried to go into closed loop in the log you posted.
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I have a set of LS1 valve covers and a LS1 PVC hose assembly on the LS1 intake. I hooked the PVC up per the stock diagram that's floating around on the web, but I know that's correct.
Just as a test I removed my IAC and turned the key, it pulled the pintle all the way in and never moved from that point.
I took some tape and blocked the hole in the IAC mount on the throttle body, started the car up. Which if it was installed it would be all the way opened..which equals high idle
It idles a little rough, but leveled out smooth and quiet...that's what I am trying to get lol
I replaced the o-ring on the IAC and put it back on the throttle body... started the car....back up to 1600 rpm idle again
I don't have a full exhaust under it yet btw...just mufflers attached to the downpipes past the o2 sensors.
So know I need to determine if it's a bad IAC valve, wiring or computer settings
Just as a test I removed my IAC and turned the key, it pulled the pintle all the way in and never moved from that point.
I took some tape and blocked the hole in the IAC mount on the throttle body, started the car up. Which if it was installed it would be all the way opened..which equals high idle
It idles a little rough, but leveled out smooth and quiet...that's what I am trying to get lol
I replaced the o-ring on the IAC and put it back on the throttle body... started the car....back up to 1600 rpm idle again
I don't have a full exhaust under it yet btw...just mufflers attached to the downpipes past the o2 sensors.
So know I need to determine if it's a bad IAC valve, wiring or computer settings
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I'll put some antifreeze in the motor and get a longer reading (to warm up) in a little bit.
How long of a scan should I do? Maybe 5 minutes?
I can get a new IAC locally for around $100, but I didn't want to get one if I didn't need it.
Thanks again
How long of a scan should I do? Maybe 5 minutes?
I can get a new IAC locally for around $100, but I didn't want to get one if I didn't need it.
Thanks again
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ok, will do
I grabbed this scan and got it to operating temps. Again I am learning this, but it feels good to start making some headway
Thanks for the help, I'll get another scan with IAC pid in a few minutes
I grabbed this scan and got it to operating temps. Again I am learning this, but it feels good to start making some headway
Thanks for the help, I'll get another scan with IAC pid in a few minutes
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well crap, the copy of HP tuners on my laptop is tied to my computer..so is there a reason the idle drop down isn't there?
I installed a copy of VCM scanner on my desktop and I have that list. It's not tied to anything yet
I installed a copy of VCM scanner on my desktop and I have that list. It's not tied to anything yet
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could it be possible that the IAC functions weren't enabled when I had the PCM tuned? The whole reason I bought this HP tuners was to be able to see what's going on with my tune and make sure there isn't anything out of the ordinary with it
Here is what I've found. Looking at Alldata to try and get the wiring pin outs for a IAC on a 04 Express van, Alldata shows that vehicle to be a DBW vehicle with a TAC module. Looking at your tune file the ETC option has been turned off in the General>System Options tab. I just downloaded a 04 Express van file from the HPT repository and it has the ETC enabled in the tune. What I'm not sure of is if you deselect the ETC option in the System Option table that it makes the OS a DBC OS. Judging by your problems I would guess not.
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Thanks, I scanned for a few minutes..I don't like to run the car with this kind of RPM for very long
Looks like the count was at 0 most of the time. NOt sure what that means
Looks like the count was at 0 most of the time. NOt sure what that means
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Here is what I've found. Looking at Alldata to try and get the wiring pin outs for a IAC on a 04 Express van, Alldata shows that vehicle to be a DBW vehicle with a TAC module. Looking at your tune file the ETC option has been turned off in the General>System Options tab. I just downloaded a 04 Express van file from the HPT repository and it has the ETC enabled in the tune. What I'm not sure of is if you deselect the ETC option in the System Option table that it makes the OS a DBC OS. Judging by your problems I would guess not.
http://www.lt1swap.com/cable_conversion.htm
I did the pin-outs as suggested for the TPS and IAC and even used the correct wire.
I sent the PCM to him to get the tune based on either GTO or express Van DBC to reflect my engine and mods done around it
Doca scsn and see what the vehicle speed sensor is showing. Anything over 0 will do exactly what you described, we went through this on my little brothers truck before we hooked up the speed sensor then again because the wiring was too close to the spark plug wires and was getting interference.
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Looking at the IAC table on this spreadsheet it starts at around 203, then goes to 315 at one point, then drops to zero for a bit
Then slowly picks up from 20 or so until around 183 before I shut the car off
Is this normal? Or anything out of wack
Then slowly picks up from 20 or so until around 183 before I shut the car off
Is this normal? Or anything out of wack