Vortech Trouble Shooting

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Shinichi

Shinichi

Joined
Mar 28, 2006
Threads
77
Messages
569
Location
Basalt, Co
Hi guys, finally got her back and running. Thanks to the guys at Proffitt's for slipping me in their busy schedule. Now the fun begins, I have some bugs that need working out. First a little background. I have an '03 motor that I mistakenly thought was an '02 motor. My computer and harness were made for an '02. Shouldn't be a huge problem, but I think some of the trouble I am having may have its root there.

First, no signal from the 02 sensors. I am only using ones for before the cats, cause there are no cats and only 2 02 sensors. I have figured out after replacing my used ones that '03 sensors ground at the computer, '02 and earlier ground elsewhere. So I have some '00 02 sensors now, that howell sugested using, but still no signal.

Next, surging idle. The code reads fast idle, and the surging may have to do with the lack of 02 signal and nothing with the code. I changed to a manual throtle body. When I did this I plugged the tube coming off the upper side of the throttlebody itself and used the one that is on the intake because it was already hooked up. it looked like it shouldn't make a difference, but I don't really know.

Last, Again this may have its root in the lack of 02 signal, but it will cut out when I really get on it, and blow a cloud of unburned gas out the back. I thought it was a wide open problem, but it has done it at 3/4 throttle too.

FYI, Vortecs rule. even with a few bugs to workout this thing huals ass.
 
Check for Vacuum leaks first! Also check your IAC valve to make sure it is getting signal. This will cause your surge and idle issue. Lastly the O2 sensors. Plugging that tube is not a problem. Are you getting sensor signal from the 02? Just checking all the major ones. And yes you are right Vortecs rule! :flipoff2: BTW CONGRATS!!
 
IAC vavle? Where is this? Everything is plugged up as far as I can tell. It actually runs pretty smooth until it warms up, then it runs ultra rich. Default mode I am sure. The ECU seems to think there are no O2 sensors. How do I check that they are grounded properly and getting the right juice. I have the wires going to the correct ones on my harness. I double, tripple checked this while changing $300 worth of sensors.
 
Iac is above your TPS sensor. It is what controls your IDLE. Idle Air control valve. They have a special little tool to check it. You may just need to take it off and clean it up some. Who did the ECU programming and harness. Howell? I am at work right now but there was a TSB on the grounding issue with the sensors on this year models. I can get you a diagram in the morning for the wiring. Then you can go direct ground. Speaking of grounds do you have good block, batt and harness grounds?
 
in my 03 when I went duals and ditched the cats I used the obd2 bypases fum summit. The missing sig from the down streem o2 will cause several problems. The bypases fool the comp in to thinking every thing is a ok.
And verify ALL GROUNDS are available. check the same generation truck and be shure to have the same grounds in the same places the factory has them.
Even the tbi I put in my 40 was very picky when it came to proper grounds. Sign on to alldata through autozone.com you will pay around 20 bucks for the year but it is definatly worth it.
 
Proffitts did their best to make sense of the jumbled mess I dropped off, and I can't thank them enough. Howell made the harness and programed the ecu. I made the mistake of reading the vin tag wrong and thinking it was an 2002 motor I had everything made for that application. Once I got to putting it together I broke a piece. When I called GM to get the part, I gave them the vin, and he told me that I had a 2003 flex fuel motor. I already had all the stuff, and howell thought it would work. The 02 sensor problem is the main issue. I think everything else is working.

On a side note. I store and ocasionally move a 2002 suburban with the same 5.3. After the battery has been disconected for a while, and I start the suburban, the idle is the same as what is happening with the 60. In my limited understanding I think it is in default, or limp mode. After a few minutes the suburban gets its stuff together and we are on our way. The 60, because we are getting no signal from the 02, stays in limp and runs super rich.

Iantscared, if there is an alternate way of hooking up the 02 sensors please let me know how to try it. I know now that from the 02 sensor black is ground, gray is 12v, and the two whites are for the computer. should I simply test the harness by hooking a ohm meter to the harness's O2 ground and look for 0 ohms. then look for 12v from the the harness's 02 hot side. Is it that simple? can I hard wire the O2 sensor direct to the battery and chasis.

The work that Proffitts did is Pro. All grounds are new and solidly connected. I think the problem lies somewhere in the 2002/2003 mistake that I made.
 
TURNMEOVER said:
in my 03 when I went duals and ditched the cats I used the obd2 bypases fum summit. The missing sig from the down streem o2 will cause several problems. The bypases fool the comp in to thinking every thing is a ok.
And verify ALL GROUNDS are available. check the same generation truck and be shure to have the same grounds in the same places the factory has them.
Even the tbi I put in my 40 was very picky when it came to proper grounds. Sign on to alldata through autozone.com you will pay around 20 bucks for the year but it is definatly worth it.
Click to expand...

I had the program made to run only two 02 sensors. It has worked many times before. Maybe I should just send the ecu back and have one made for the 2003 motor istead of trying to make the motor work like an '02.
 
OH BOY!!! That makes a difference in the whole game. For one the flex fuel does have the drive by wire and I hope it was detuned. Also the fuel pressure is higher on the flex units. Take the ground directly to frame. Check for return signal on the hot side to the ecu. If you don't get signal there is a problem in the ECU. I have had to send the ECU back for reflash due to a high idle and rich condition but I would make sure the sensors are reading first. Do you have a tech II or genysis? If you don't a local shop would be able to slap it on and tell you if all the sensors are working or if a missing parameter is needed. And you are sure that is the VIN and ECU from the donor? I will post up a pic of a flex fuel injector. That is the easy way to tell. But at this point you really need a good scanner so you can se what your percentages are at throttle and how the corrosponding sensors react.
 
Take your whole rig to a local GM tuning place and have them tune the ECM while it's on the vehicle. With LS1edit (or the likes) they can delete any of the sensor codes from the ECM that you are not using, or are not hooked up, to make it run up to snuff. IIRC the original throttle body is fly-by-wire so there is no IAC since it's controlled by the throttle electronically.
 
Oh boy!

My scanner is Actron. It was the only one my local NAPA had. I don't think it has a "use it while running feature," but I will check the manual.

Someone early on told me to stick to a 2002 or older motor, and I thought I had. I think the listing was wrong when I puchased it. To get my manaul throttle body I bought an entire 2002 intake manifold, including the '02 injectors. The 2002 injectors have two small holes, the 2003 injectors have 4 very small holes. Should I put the the entire 2002 intake on the motor so that I have an IAC. Or, would getting an electronic pedal and putting the original throttle body back on be the way to go. I would rather leave it how it sits if it can be made to work.

I still have my original ecu. I never sent the core in. Is the harness connection different from '02 to '03. If I find a "tuner" would using the original computer be best? I guess the tuner would know that.

My scanner says all siganls are accounted for (except O2). I think I will start with checking the O2 ground and hot and see what I get.

The funny part is that right now my 60 sounds and smells like a full on hot rod. If it wasn't for the 8 mpgs, and the black smoke, I probably wouldn't have been concerned.

As far as a GM tuning shop, what should I look for? Labor is $100 an hour minimum around here.
 
If you already have the old ECU I would send it to be flashed as a back up. But keep at the 02 sensors. If you get nothing from the sensors it will be the ECU. Also what color are the pin connector plugs on the ECU you are using now? Blue red or Blue green? BTW where's the picture of the beast?
 
Up early too? Woke with dreams of wiring and blue smoke. My wife thinks I am nuts.

The ecu plugs are from howell, and they are grey. The OE harness is in storage I will check it out after work. Thanks for your help.

I will take some pictures. Been trying to get it to run right and haven't taken any yet.
 
The colors on the ECU itself. That is how you tell if you have the correct Delphi ECU. And yeah I work the night shift now. So during the day I turn a wrench. Works good on the schedule.
 
Awesome thanks for the info. I will sit and try to digest this stuff tonight. I have tomorrow off to try and make some head way.
 
Turns out that the computer is a 2000. This is good because I have 2000 02 sensors.

Now to go track down the problem.
 
Good news is that I have full voltage on the harness side. I have the right O2 sensors for the computer. The computer has no colors at the harness. only grey, metal.

Now what?

My code reader does only that. It does not have a diagnostic feature.
 
might be on to something here. I might have switched the o2 sides. I am going to switch them and go for a ride.
 
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