S10 4.8 Vortec 5.7 LS

**stempy** · 04-29-2014, 12:23 AM

I am new here. Here is my question. The base for the LS implant is a 1994 GMC Sonoma 2.2 5 speed. We initially started with a 2004 Silverado 4.8 Vortec but concerns regarding the heads and possible coolant leaks I opted for a PK Machine LS1 5.7 with the Silverado intake, injectors, and coils. I installed a set of aftermarket fuel rails to incorporate a fuel pressure regulator and we machined a set of fuel rails hold downs that also support a set of coil relocation brackets. The Silverado was drive by wire and needed to convert to a mechanical throttle body. The harness is a Current Performance harness configured for a mechanical throttle. The radiator is now in set in to the radiator support so the mechanical fan could be reused and that has somewhat restricted the clearance between the throttle body and the fan. Here is my dilemma. I think the harness is wired for a 1999 Camaro throttle body but I am not sure. We went with all of the emissions devices and I want to be as close to certain that the throttle body I purchase is what I need. The harness supplier has been less than stellar in their technical support. This truck is not being built as a street rod but as a purpose built work truck and as a side note note I have owned it since new in 1994 with the exception of some time my Father had it. Here is a picture of what I believe are the plugs related to the throttle body. Throttle Position Sensor and ???. Any help will be appreciated.

https://www.dropbox.com/s/jbugy4il3f...2012.57.03.jpg

Thanks Jon Thompson

**pajeff02** · 04-29-2014, 02:22 AM

Welcome to the site!

Looks like the plug on the left is the TPS (throttle position sensor) and the one on the right is the IAC (idle air control). Possibility that they are also the MAF (mass air flow) and the IAT (intake air temperature) as they are similarly configured and at the same location in the stock harness. The latter connectors would be longer though to reach the MAF and the air box.

**stempy** · 04-29-2014, 02:36 AM

Originally Posted by pajeff02

Welcome to the site!

Looks like the plug on the left is the TPS (throttle position sensor) and the one on the right is the IAC (idle air control). Possibility that they are also the MAF (mass air flow) and the IAT (intake air temperature) as they are similarly configured and at the same location in the stock harness. The latter connectors would be longer though to reach the MAF and the air box.

Thanks. The MAF harness is there but much longer as you said. So could you direct me to a throttle body and the sensor(s)? I was looking at one on ebay from potz_speed_and_performance but wasn't sure if it was what I needed. Thanks Jon

**pajeff02** · 04-29-2014, 03:02 AM

I am not familiar with the throttle body you are referring to. Some come with the sensors included, and on others you have to transfer your existing sensors -- which in this case you do not have. I believe that both Summit and Jegs sell throttle bodies that are ready to go. In stock configuration, they will support builds well north of 400 hp, which is essentially a cammed LS1.

**stempy** · 04-29-2014, 03:34 AM

Originally Posted by pajeff02

I am not familiar with the throttle body you are referring to. Some come with the sensors included, and on others you have to transfer your existing sensors -- which in this case you do not have. I believe that both Summit and Jegs sell throttle bodies that are ready to go. In stock configuration, they will support builds well north of 400 hp, which is essentially a cammed LS1.

Thanks. I guess what I am asking is, how to id the correct sensors and if the the throttle body has the accommodations for the sensors. I tried to include a link but it would not post. Just sent an email to the harness people and asked what sensors the harness was built to accept but hopes are not high that I will get a reply. Thanks Jon

**pajeff02** · 04-29-2014, 05:16 PM

Here's a good pic of the stock throttle body setup. You can see the larger plug for the TPS and the smaller IAC:

**stempy** · 04-29-2014, 09:34 PM

Thanks I appreciate all the help. I did get a reply from the harness people, here it is: "All of the GM LSx and Vortec engines TPS and IAC are wired the same. So it would be wired for any one of them." So I assume that there is no difference in signal from one another? Thanks Jon

**pajeff02** · 04-30-2014, 02:58 AM

No, the signal should be the same. GM likes to use a 5 volt reference signal for most of its sensors. It then reads the range from 0 to 5 volts and sends this output to the PCM to determine what is going on.

**stempy** · 04-30-2014, 03:37 AM

Thanks. OK. So the fastener pattern and where it engages the throttle shaft will be the same? I am going to order the sensors for the mechanical Camaro throttle body versus the donor Drive By Wire Silverado Throttle body to be safe. Does that make sense? Thanks Jon

**pajeff02** · 04-30-2014, 10:26 AM

I believe so. You have something other than the drive-by-wire throttle body to install them in?

**stempy** · 04-30-2014, 11:00 AM

That is how this all started trying to configure a mechanical throttle body. Thanks Jon

***SMWS6TA*** · 04-30-2014, 11:10 AM

Please post pics up when you can (need to use Photbucket & copy the url.

I'm interested in doing something like this for my sons Blazer. I've been reading up but need to wait till I finish my TA build first.

**stempy** · 05-06-2014, 01:49 PM

OK here is another one for you guys. I am using LSbrackets.com for the accessories brackets. I needed to change the upper water pump hose connection to the left, as mine is a truck water pump and the upper connection is on the right. I asked the bracket guy what pump has the upper connection on the left (as pictured on his website) and he said it was a 2010 Camaro water pump. I can not find one from my jobber and looked online with zero luck. Any help?? Thanks

**stempy** · 05-20-2014, 11:27 PM

OK here is another one for you. Looking at Taylor Wire and MSD for a cut to length set of LS1 coil wires. Relocated coils to get around an over sized brake booster so we fabricated a new set of coil brackets, still on the valve covers but different spacing. Any help/part numbers? Getting closer to an initial start up. Will post pictures and answer questions with completion and hopefully success. Thanks Jon

**pajeff02** · 05-21-2014, 02:17 AM

Water pump through GM Parts Direct is only $167.71. You can see a picture on their website (click the link on the right side of this page, then open their Parts Catalogue and search it). Looks like any other LS style water pump to me, so not sure if there is a difference from what you have.

**stempy** · 05-21-2014, 04:22 AM

Originally Posted by pajeff02

Water pump through GM Parts Direct is only $167.71. You can see a picture on their website (click the link on the right side of this page, then open their Parts Catalogue and search it). Looks like any other LS style water pump to me, so not sure if there is a difference from what you have.

I just spent the better part of an hour detailing the water pump details and it would let me post. It has happened before and does not encourage me to spend time posting. Jon

**pajeff02** · 05-21-2014, 04:29 PM

I had some trouble accessing the site today from my office. Normally, I don't have any issues so something must have been out of sorts.

**stempy** · 06-15-2014, 02:22 AM

OK well here is an update. The water pump was a real adventure. I need a mechanical fan as it will be pulling a purpose built trailer and that fact is what caused the water pump issue. 2010 Camaro pump shaft is 5/8 (actually a proprietary size .646 or something like that which I did not write down and can not remember) and the 2004 Silverado shaft is 3/4 (same thing not and standard o.d.) so we machined a press in bushing to install the truck pulley on the Camaro smaller diameter shaft. Bad idea. As I followed through with this idea I knew it was not bullet proof as the lighter engineered Camaro pump shaft and bearings would most likely fail over time due to a mechanical fan hung off the front. Well the decision to abort this approach was made for me when I detected a slight tolerance in the bearing/shaft after the press. So one new Camaro pump in the scrap and on to the next plan. We took the original 2004 Silverado pump upper formed elbow out of the housing with heat. It is a slip fit with some sort of compound as an adhesive and sealant. I then called LOCTITE technical to see if they had a product to reinstall the elbow as factory. They were very helpful and confident in their recommendation LOCTITE 638 with a primer activator. We created a sweep out of the two truck pump elbows, followed the LOCTITE procedures and we were finally done with that issue. HOWEVER I ended up talking to the guy at LS Brackets and he rattled off the Camaro pump with the same size shaft as the truck pump. The upper connection on the Camaro pump is on the left as needed but buried behind the crank driven mechanical fan. LS Brackets has been very helpful and knowledgeable. I will provide pictures as soon as I can. Jon

**stempy** · 06-15-2014, 02:31 AM

Next. Due to interference of the coil pack on the left side with an updated 3500 series brake booster we had to move the coil location up for clearances. We modified two AUDI LS coil conversion brackets and pushed the coils to just above the valve covers. I now need a part number for a set of plug wires or components to cut to fit for the plug wires. Any HELP? Thanks Jon

**stempy** · 07-14-2014, 09:59 PM

I ordered a set of Taylor custom built to spec plug wires, less than a hundred dollars with shipping and had them in just a few days. Nice stuff and very helpful with over the top customer service.