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Monday 9am - 5:30pm Tuesday 9am - 5:30pm Wednesday 9am - 5:30pm Thursday 9am - 5:30pm Friday 9am - 5:30pm

Nelson Performance

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San Antonio, TX
Nelson Performance

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GM LS & LT Performance, Diagnostics & Tuning LSx Performance Specialists
Trucks/cars/suv
GO FAST! In house dyno, tuning, custom wiring, installation, parts.

HPTUNERSD - FAST XFi - Holley EFI

Please contact Nelson performance at 210-626-0278 or at [email protected] for any orders or detailed pricing questions/ inquiries.

10/18/2026

🔧 **TECH TIP SUNDAY!** 🔧

🚨 **A MISFIRE DOESN'T ALWAYS MEAN A BAD LIFTER!**

Your engine starts running rough, hesitating, or misfiring, and suddenly you're worried about one of the most expensive repairs on your GM engine. 😳💸

But here's something you should know!

⛽ A failing fuel injector can cause symptoms that feel very similar to a mechanical engine problem.

A faulty injector may:
🔴 Deliver too much or too little fuel
🔴 Cause intermittent misfires
🔴 Create hesitation or loss of power
🔴 Cause rough running under certain driving conditions

And here's the tricky part: **An injector can malfunction intermittently, making the problem harder to pinpoint.**

That's why proper diagnostics matter!

At Nelson Performance, we don't automatically assume a misfire means lifter failure. We test the fuel, ignition, electrical, and mechanical systems as needed to identify what's actually causing the problem.

💡 **Today's takeaway:** A misfire is a symptom, not a diagnosis!

🔧 **NELSON PERFORMANCE**
Tuning. Diagnostics. Results.

10/17/2026

🚨😴 CAUGHT SLEEPING ON THE JOB!

JUST KIDDING! 🤣🔧

This C10 is getting a **complete chassis rewire**, and that means getting into some pretty interesting positions!

We're replacing the old wiring harness along with those crusty, aging electrical connectors, terminals, sockets, and pigtails. Years of heat, corrosion, and wear can take a toll on electrical connections, so we're making sure the new wiring has reliable connections throughout.

It's tedious work, but doing it right matters! 💪

Who needs yoga when you work on classic trucks? 🧘‍♂️😂

🏁 Nelson Performance
Tuning. Diagnostics. Results.

10/16/2026

🚨 **ALL THE WAY FROM EAGLE PASS, TX!** 🚨

**Multiple shops. A dealership. Still misfiring!** 😳🔧

This 2019 Chevy Tahoe made the trip from Eagle Pass to Nelson Performance after several unsuccessful attempts to get to the bottom of an intermittent misfire.

Here's what we were working with! 👇

🔴 The dealership suspected the fuel pumps.
🔴 Coils and spark plugs had already been replaced.
🔴 The misfire continued, primarily during highway driving.
🔴 The customer feared he might have a failing lifter. 💸

**ENTER RAY!** 💪🔍

In LESS THAN ONE HOUR, Ray narrowed the problem down to **TWO faulty fuel injectors!**

✅ Fuel pressure checked out GOOD!
✅ No evidence of lifter failure!
✅ Two problem injectors identified!

We recommended replacing all the injectors and associated harnesses. Unfortunately, our customer couldn't stay for the repairs, but he left with something he hadn't gotten elsewhere — **ANSWERS!** 🙌

💰 And those answers could save him THOUSANDS in unnecessary repairs!

❤️ To our customer from Eagle Pass, THANK YOU for making the drive and trusting our team!

🏁 **STOP GUESSING. START DIAGNOSING.**

📍 Nelson Performance | San Antonio, TX

**TUNING. DIAGNOSTICS. RESULTS.**

10/15/2026

🔥 **2003 GMC SIERRA — NOT EVERY FIX NEEDS A REPAIR BILL!** 🔥

This beautiful Sierra is no stranger to Nelson Performance! 😎💪

We've had the pleasure of working on this truck before, including a full custom tune, fuel injectors, fuel pump, and O2 sensors.

When a customer continues to trust us with their vehicle, that means something to us. We appreciate that loyalty, and we don't take it for granted! ❤️

🔧 **SO WHAT BROUGHT HIM BACK?**

The customer wanted an idle adjustment and thought the truck needed a retune.

Allen hooked up the laptop to take a look, and guess what we found? 👀

🌡️ **The engine temperature sensor was UNPLUGGED!**

Here's why that matters! 👇

The engine computer relies on temperature readings to determine how much fuel the engine needs and how to manage certain operating conditions. When that information is missing, it can affect how the engine runs, including idle quality.

✅ Sensor reconnected.
✅ Issue identified.
✅ No retune necessary.
✅ **NO CHARGE!** 💯

We could have charged for a tuning adjustment, but the truck didn't need one.

**THAT'S THE DIFFERENCE BETWEEN SELLING A SERVICE AND SOLVING A PROBLEM!** 🔥

At Nelson Performance, we're not here to sell you something your vehicle doesn't need. We're here to figure out what's actually wrong and get it right.

Sometimes it's a major repair. Sometimes it's a simple connection. Either way, you deserve an honest answer.

🤝 To our returning customer, thank you for continuing to trust us with your Sierra. We appreciate your business!

🏁 **NELSON PERFORMANCE**
*Tuning. Diagnostics. Results.*

10/12/2026

🚨 **NO START! AND THIS ONE HAD A TWIST!** 💀🔧

Sometimes the biggest problems start with the smallest shortcuts! 👀

This 2017 GM engine came to Nelson Performance with a **NO-START condition.** During diagnostics, we discovered there was NO fuel pressure coming from the high-pressure fuel pump.

Time to investigate! 🔍

Our inspection uncovered something interesting...

The customer had installed a fuel pump that wasn't correct for this engine. The electrical connectors weren't compatible, so instead of using the correct pump, they decided to **JUMP THE CONNECTIONS WITH WIRES!** 😳⚡

Take a close look at that picture. YES, those wires are connecting two plugs that were never designed to work together!

🚫 **HERE'S THE PROBLEM!**

Just because you can make an electrical connection doesn't mean the components are compatible!

Modern GM direct-injection fuel systems are precisely engineered. The high-pressure fuel pump must be compatible with the engine's fuel system and control strategy.

A couple of jumper wires won't magically make the wrong pump work!

⚠️ Incorrect components and improvised wiring can lead to:
🔴 No-start conditions
🔴 Fuel pressure and control issues
🔴 Electrical faults
🔴 Potential damage to expensive components
🔴 More money spent diagnosing and correcting the original mistake

💡 **THE TAKEAWAY?**

**THE RIGHT PART MATTERS JUST AS MUCH AS THE RIGHT INSTALLATION!**

Saving a few dollars or trying to make an incompatible part work can turn into a much more expensive repair.

At Nelson Performance, we don't just throw parts at a problem. We investigate, test, and find out WHY something isn't working.

👀 **BEFORE YOU READ THE CAPTION, DID YOU SPOT THOSE JUMPER WIRES?**

Drop a 🔧 if you caught it!

**NELSON PERFORMANCE**
TUNING. DIAGNOSTICS. RESULTS.

10/11/2026

🔧🎃 **TECH TIP SUNDAY!** 🎃🔧

🩸 **YOUR ENGINE IS THIRSTY… AND YOU MIGHT NOT EVEN KNOW IT!**

🚨 Just because your truck isn't leaking oil doesn't mean it isn't LOSING oil!

Did you know some GM engines can burn oil between oil changes without leaving a single drop on your driveway? 😳

By the time you notice, damage may already be happening!

🔍 **WHERE IS YOUR OIL GOING?**

🔴 **AFM/DOD Systems:** Certain GM engines equipped with Active Fuel Management have known oil consumption concerns.

🔴 **Piston Rings:** Worn or stuck rings can allow oil into the combustion chamber, where it burns with the fuel.

🔴 **PCV System:** A malfunctioning ventilation system can pull excessive oil into the intake.

🔴 **Valve Stem Seals:** Worn seals can allow oil into the cylinders, sometimes causing blue smoke at startup.

💀 **HERE'S WHERE IT GETS SCARY!**

Running low on oil can cause:

⚠️ Camshaft and lifter damage
⚠️ Timing chain and valvetrain wear
⚠️ Bearing damage
⚠️ Complete engine failure 💸

🚨 **DID YOU KNOW?**

Your oil pressure gauge is NOT an oil level gauge!

Your engine can be dangerously low on oil and still show oil pressure.

🛠️ **HOW DO YOU PROTECT YOUR ENGINE?**

✅ Check your oil regularly between changes.
✅ Monitor how much oil you're

10/10/2026

🏁 **MONDAY'S BUILD. FRIDAY'S HEAD START!** 🔥

This 2008 Corvette wasn't scheduled to start until Monday… but it's Friday, the car is here, and our guys aren't wasting any time! 💪🔧

We're getting a jump on the teardown so we can get this Corvette ready for its next chapter!

👀 **Now take a GOOD look at that parts cart!**

What do YOU think we're getting ready to install? 🤔

We're not spilling the details just yet! 😎

We'll be taking you along throughout the build — from teardown to installation, tuning, and the finished product.

🔥 **FOLLOW ALONG for progress reports and the big reveal!**

👇 Drop your guesses in the comments. Let's see who knows their Corvette upgrades!

10/09/2026

🚨 **CAME IN FOR A TUNE… BUT THE TRUCK WOULDN'T EVEN RUN!** 😳

Well, that's a problem! 😂

This customer brought their truck to Nelson Performance for a custom tune. But before we could even THINK about tuning it, we had to figure out why it wouldn't run!

🔍 **TAKE A LOOK AT THESE TWO JARS!**

🟢 **LEFT:** Fresh, clean gasoline.

🟠 **RIGHT:** Fuel pulled straight from the customer's truck.

😱 **SAME TYPE OF FUEL. VERY DIFFERENT APPEARANCE!**

That dark, discolored fuel is a BIG red flag! 🚩 It can indicate aged or degraded gasoline, contamination, or other fuel-quality issues that need to be investigated.

⚙️ **HERE'S YOUR LESSON FOR THE DAY!**

Your engine depends on clean, properly functioning fuel to run correctly. Poor-quality or contaminated fuel can contribute to:

🔥 Hard starting or a complete no-start

🔥 Rough idle, hesitation, and misfires

🔥 Poor acceleration and loss of power

🔥 Fuel system and injector problems

🔥 Inconsistent combustion and performance

And here's the kicker…

💻 **NO AMOUNT OF CUSTOM TUNING CAN FIX BAD GAS!**

At Nelson Performance, we're not interested in simply plugging in a laptop and sending you down the road. If your vehicle has an underlying issue, we want to identify it BEFORE we start making calibration changes.

Because a great tune starts with a HEALTHY engine! 💪

🎃 **THE SCARIEST THING UNDER YOUR HOOD MIGHT NOT BE WHAT YOU THINK!**

📍 **NELSON PERFORMANCE**
San Antonio, Texas

**TUNING. DIAGNOSTICS. RESULTS.**

10/08/2026

🔥 **DON’T LET HEAT EAT YOUR INVESTMENT!** 💀🔥

You just spent BIG MONEY on a new transmission and torque converter… so why let HEAT destroy your investment? 💸😱

🔧 **2012 Chevy Tahoe — Transmission Cooler Installation!**

Here's something every truck owner should know! 👇

🌡️ **HEAT IS ONE OF YOUR TRANSMISSION'S BIGGEST ENEMIES!**

Your transmission generates heat every time you drive, and an aftermarket torque converter, especially one with a higher stall speed, can generate even MORE heat under certain driving conditions!

Excessive transmission temperatures can lead to:

🔥 **Fluid Breakdown** — High temperatures accelerate fluid deterioration, reducing its ability to lubricate and protect internal components.

⚙️ **Premature Wear** — Excessive heat can damage seals, clutches, and other critical transmission components.

💸 **Expensive Repairs** — That transmission and converter combo you just invested thousands in? Excessive heat can shorten its lifespan!

🛠️ **THE SOLUTION? KEEP IT COOL!** ❄️

An appropriately sized auxiliary transmission cooler helps dissipate excess heat, maintain healthier operating temperatures, and protect your investment.

And here's the important part: **A transmission cooler isn't just for towing!** Trucks with performance upgrades, higher-stall converters, or demanding driving conditions can benefit, too!

💡 **NELSON PERFORMANCE TECH TIP:** Bigger isn't always better! Proper cooler sizing, installation, and maintaining the correct operating temperature are key. Your transmission still needs to reach its intended operating temperature to perform properly.

👻 **Don't let overheating turn your expensive upgrades into a mechanical NIGHTMARE!**

🏁 **BUILD IT RIGHT. KEEP IT COOL. PROTECT YOUR INVESTMENT.**

📍 Nelson Performance | San Antonio, TX

10/07/2026

⚡ IT’S ALIVE… ALMOST. ⚡
This 1966 K10 is definitely a Frankenstein build — old-school Chevy on the outside with a much newer heart underneath. 🧟‍♂️🔧
Under the hood:
⚙️ 2017 5.3L L83
⚙️ 6L80E transmission
⚙️ Stage 2 cam
⚙️ Headers
The customer handled the install, and now it’s here at Nelson Performance for us to troubleshoot the build, make sure everything is working together correctly, and finish it off with a CUSTOM TUNE.
Customer-installed swaps can be a little bit of a mystery when they arrive. Before we start tuning, we have to verify the mechanical and electrical side of the build is doing what it should. A tune can optimize a good combination — but it can’t fix an installation problem.
Once we get this monster sorted out, it’s time to bring it to life. ⚡💀
Follow along — we’ll show you how this one turns out!
📍 Nelson Performance | San Antonio, TX
Tuning. Diagnostics. Results.

Address

10034 Roosevelt Avenue
San Antonio, TX
78214

Opening Hours

Monday	9am - 5:30pm
Tuesday	9am - 5:30pm
Wednesday	9am - 5:30pm
Thursday	9am - 5:30pm
Friday	9am - 5:30pm

Telephone

+12106260278

Website

http://www.nelsonperformance.com/

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