LQ4 intake/harness help/advise

[TazmanB]

Well I had a complete 01 LQ4 out of an 01 Denali fall into my lap. It is a complete motor minus the wiring harness, ecm and of course no pedal or TAC. I was told the motor was no good so I tore it down and found it had a spun main bearing. I found a fresh rebuilt 06 LQ4 short block for CHEAP and swapped the heads and everything else over and now it is sitting as a long block. I have been trying to educate myself on the Vortec motors and have come across several differing opinions (surprise surprise!!!)

Anyway to get to the questions and to see if I can clear the mud out of my head a little bit here goes. I have everything I need to take it back to a complete 01 style motor but have been looking for a wiring harness, ecm, pedal and TAC that will work and get it running. From what I have seen the 01-02 LQ4's seem to be a pain in the a$$ since they are what seems to unique to those years. And to add to it the required parts to get it running (ecm and TAC) appear to be much higher priced. I was thinking if I could find a complete 06 intake with fuel rails, injectors and TB then I could get the less expensive ecm, pedal and TAC. Does this sound like a good route to go or should I be looked at doing something else. I am trying to put this motor back together as inexpensively as possible because cost is an issue.

Oh and I will be looking to put a 4l80e with it.

[BR3W CITY]

was the original 01 an iron-head motor?

[TazmanB]

Originally Posted by BR3W CITY

was the original 01 an iron-head motor?

No the motor had aluminum heads. That is another thing that is making me wonder because I know the 01 should have had iron heads. I will get a pic tomorrow. I was also thinking that the throttle body should be a 4 bolt with a 2 plug sensor but it has 3 bolds and a single sensor plug and the fuel rails are return type rails. There are several things about the motor that has me scratching my head.

[BR3W CITY]

Originally Posted by TazmanB

No the motor had aluminum heads. That is another thing that is making me wonder because I know the 01 should have had iron heads. I will get a pic tomorrow. I was also thinking that the throttle body should be a 4 bolt with a 2 plug sensor but it has 3 bolds and a single sensor plug and the fuel rails are return type rails. There are several things about the motor that has me scratching my head.

Well lets say that it is an 01, if its late production making it built like an 02.

If thats the case, the 3 bolt TB and aluminum heads make sense. In that situation, your best bet is to find; the TAC, ECM, TB and Pedal all from an 02-04 truck or van with DBW and a 4l80e (hint, look for a G-van). This will get you a matched set of components that will fit on the 3 bolt intake, run together, and be tuneable.

[ls1nova71]

Originally Posted by BR3W CITY

Well lets say that it is an 01, if its late production making it built like an 02.

If thats the case, the 3 bolt TB and aluminum heads make sense. In that situation, your best bet is to find; the TAC, ECM, TB and Pedal all from an 02-04 truck or van with DBW and a 4l80e (hint, look for a G-van). This will get you a matched set of components that will fit on the 3 bolt intake, run together, and be tuneable.

99-00 6.0's had iron heads, pretty sure 01 was when they switched to aluminum. Also all Gen3 engines used 3 bolt TBs. You will need the all plastic TAC module and a red/blue PCM, like a 411, this DBW was used on 01 and 02 truck. Personally i dont see anything wrong with this set up at all. And, just an fyi. I searched high and low to find a pre 08 van with DBW and never found one, even though Mitchell wiring diagrams show there was an option for it.

To the OP, If you need a TAC, let me know, I have some. The pedal is the same from 01-05 so they are easy to find.

[TazmanB]

Originally Posted by Clyde65

Tarzan! Hello neighbor!

I am in Ft Worth! Have you checked with the WY on Mansfeild Hwy, First one, left side as your heading south! they used to have tons of vans and have been real good to me when I was doing my swap!

Good luck!

No I have not checked there yet. Planned on hitting the WT's Monday to see what I can find.

Originally Posted by ls1nova71

99-00 6.0's had iron heads, pretty sure 01 was when they switched to aluminum. Also all Gen3 engines used 3 bolt TBs. You will need the all plastic TAC module and a red/blue PCM, like a 411, this DBW was used on 01 and 02 truck. Personally i dont see anything wrong with this set up at all. And, just an fyi. I searched high and low to find a pre 08 van with DBW and never found one, even though Mitchell wiring diagrams show there was an option for it.

To the OP, If you need a TAC, let me know, I have some. The pedal is the same from 01-05 so they are easy to find.

I was at the shop this morning to take another look at the TB to make sure I was remembering everything right and this is what I found that I was wrong about. The TB is a 2 plug TB which takes a different TAC than the 1 plug but everything else was what I stated before.

I will be needing an ecm with wiring harness, TAC with matching pedal and harness for either the 2 plug TB or 1 plug if I find one that is reasonably priced.

Does anyone see an advantage or disadvantage to turning this into a 03-06 style motor since I will have to get all the parts above anyway? And what about the fuels, should I leave the return type or go with the returnless style?

[clinebarger]

Originally Posted by ls1nova71

99-00 6.0's had iron heads, pretty sure 01 was when they switched to aluminum. Also all Gen3 engines used 3 bolt TBs. You will need the all plastic TAC module and a red/blue PCM, like a 411, this DBW was used on 01 and 02 truck. Personally i dont see anything wrong with this set up at all. And, just an fyi. I searched high and low to find a pre 08 van with DBW and never found one, even though Mitchell wiring diagrams show there was an option for it.

To the OP, If you need a TAC, let me know, I have some. The pedal is the same from 01-05 so they are easy to find.

There is not a problem as far as functionality, Availability can be an issue though.

Tazman, I do have a Harness from a '02 Sierra C3 LQ4/4L65E. If LS1Nova has the PCM & TAC you will be in good shape!

[clinebarger]

Early DBW/Traction Control, This set-up was used in '99-'04 Vettes & '01 & '02 SUV/C3 Sierras with Traction Control, Unless you have the PCM, TAC & Pedal...Don't use this set-up.

[Clyde65]

Tarzan! Hello neighbor!

I am in Ft Worth! Have you checked with the WY on Mansfeild Hwy, First one, left side as your heading south! they used to have tons of vans and have been real good to me when I was doing my swap!

Good luck!

[BR3W CITY]

My setup was a late 03 2500 time warner van

[ls1nova71]

Originally Posted by BR3W CITY

My setup was a late 03 2500 time warner van

Not to hijack... Are you absolutely positive it was a van???? I would have paid you good for a copy of that tune a few years ago. Not sure if you are aware of it, but that is the ONLY factory tune with the 03-07 DBW and also with the 12v A/C request versus the serial data A/C that the trucks come with. Just recently HPTuners added the option of switching the request signal, so its a moot point now, but its cool to actually know someone had one.

[BR3W CITY]

Originally Posted by ls1nova71

Not to hijack... Are you absolutely positive it was a van???? I would have paid you good for a copy of that tune a few years ago. Not sure if you are aware of it, but that is the ONLY factory tune with the 03-07 DBW and also with the 12v A/C request versus the serial data A/C that the trucks come with. Just recently HPTuners added the option of switching the request signal, so its a moot point now, but its cool to actually know someone had one.

I'm positive that the engine and throttle body were out of a TW van. I don't know how much my tune would have helped you though, as I had to source the ECM seperately.

Not sure if you remember, but I had to trade you that all plastic DBW pedal that I picked up for the metal one? That was when I put it all together. The ECM was off of ebay, and I can't prove what it was from. Like most ebay ads, it said something like "ECM 2002 2003 2004 Chevy GMC silverado Van " lol.

[chuckmc8]

[QUOTE=ls1nova71;6858738]Not to hijack... Are you absolutely positive it was a van???? I would have paid you good for a copy of that tune a few years ago.

ls1nova71- On my shelf, I have the ECM from a 2003 van that I bought the LQ4 from.It still has the factory tune. Do you need it still?

[ls1nova71]

Originally Posted by BR3W CITY

I'm positive that the engine and throttle body were out of a TW van. I don't know how much my tune would have helped you though, as I had to source the ECM seperately.

Not sure if you remember, but I had to trade you that all plastic DBW pedal that I picked up for the metal one? That was when I put it all together. The ECM was off of ebay, and I can't prove what it was from. Like most ebay ads, it said something like "ECM 2002 2003 2004 Chevy GMC silverado Van " lol.

I do remember that, thats why I was wondering if it was actually from a van. I didnt remember you having to piece it together. You most likely have the PCM from a truck, so it wouldn't have worked.

[quote=chuckmc8;6859150]

Originally Posted by ls1nova71

Not to hijack... Are you absolutely positive it was a van???? I would have paid you good for a copy of that tune a few years ago.

ls1nova71- On my shelf, I have the ECM from a 2003 van that I bought the LQ4 from.It still has the factory tune. Do you need it still?

It was a few years back when I was looking for one, and now HPTuners has added the option to change request signals, so I dont need one now, but thanks for the offer. Curious though, was the van DBW?

[BR3W CITY]

I prefer return style, just for the ease of switching rails, or adding an aftermarket/external FPR unit should you decide to go FI.

[aknovaman]

For the guy with the time Warner van PCM, can you email me the file from it?

[ls1nova71]

Originally Posted by aknovaman

For the guy with the time Warner van PCM, can you email me the file from it?

Anthony, he didnt get the PCM with it. Got one off eBay, so most likely a truck PCM.

[aknovaman]

Just asking if he has a PCM that works with manual ac I could get the file for reference. Not really caring what it came from but just that it works.