About this tech support page

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The most important thing to remember is to contact us BEFORE you assume something is wrong and attempt to modify something that probably does not need modification.

Ken@firstperfcenter.com

We have found through years of tech support that many people do not realize the MAP sensor needs to be connected to a vacuum port. Please be sure that this sensor is connected to a vacuum port. If this sensor is not connected to a manifold vac. port the ecm will think the engine is under a load all the time and you will have an extreme rich running situation. We recommend the MAP bracket for the FIRST tpi and that you connect right to the 1/4 vac. port next to the bracket.

Silicone on runner gaskets. Many people are using silicone on the runner gaskets when they are installed, we do not recommend this. The only silicone needed when you install the runners, would be on the lower middle passenger side runner  bolt which does protrude into a water passage.

Many people would like to try and adapt the OEM twin blade throttle body to the FIRST plenum. We do not recommend this. We have made such an adapter a few times and it creates a small opening approximately 2" X 3.250 at the entrance of the plenum.  This is very restricted. The FIRST plenum is square  and the OEM is narrow and wide, so to create a good transition to that small opening the adapter needs to be extremely thick, which causes other issues under the hood sometimes.  

If you are installing the FIRST Tpi on an existing OBD1 car and you change injector size, cam or heads etc. You will need to get the prom reprogrammed for these changes. This will insure that it runs properly.

You  should have a minimum 3/8 feed line and 5/16 return line. If the return line is restricted, it will cause a high pressure situation. We do not have a generic kit that will supply everything for your installation. There are too many variables in each project to create such a kit.  Also, we cannot carry the liability on the fittings and such required to do so. Please take your time during this modification and use all fuel injected rated items and check for leaks BEFORE you build the entire FIRST unit. Please contact us with any questions, we are always glad to help!

This is an area that many do struggle with. There are many configurations out there for throttle cable connections. This makes it extremely difficult for us to make a universal one fits all throttle body. We do offer a long throttle pin for an OEM tpi cruise/ throttle connection . The cable ends do sometimes need to be cut to fit and the corresponding connection added to your cable needs to be installed. We can help you with this if you contact us with your needs. Generally speaking worse case scenario is a lokar cut to fit cable can be used on pretty much any application.

The early style plenum required a steel diversion plate to seal off the EGR port properly. It was common for these to be removed because customers did not understand why it was there. If this plate is missing, just give us a call we have them for sale. 

This plate is needed to properly seal the EGR port so there is not a large vac. leak under the throttle body flange.

Notice the large hole that is left open under the throttle body flange when the plate is not installed. This plate is used to apply pressure for the gasket to seal.

Now you can see how the hole is sealed off when the plate is properly installed, no more vac. leak!

You can use the GM large cap distributor with the FIRST® TPI, however because of the large size of the base runner you will more than likely need to remove some of the lower casting on the dist. base to allow room for adjustment.

The FIRST® fuel rails are 6016 billet aluminum with 3/8 NPT female on each end. You can use many different combinations to make your connections. You can use hose barbs with fuel injection rated line. You can use an 3/8 NPT male to 3/8 NPT female inverted flare to use steel lines or even flare your existing steel lines. You can also adapt AN fittings to the rails. Typically we use the crossover in front for clearance reasons and use the rear exits for the main feed line and out to the fuel regulator. It is possible to use a long loop of fuel line to go around the dist. if you need to use the front for feed and return.

Part number for "standard" brand is AS5T. 

This is where the IAT sensor is typically mounted on the FIRST TPI. It can be mounted anywhere in the plenum area or intake tubing.

Part number for "standard"  brand is AX1T

This is where the IAC valve is mounted on the FIRST TPI Throttle body.

Part number for "standard" brand is AC1T