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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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United States
San Antonio, TX
Nelson Performance

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.

06/05/2026

☀️ Tow season is here, and Texas heat is hard on trucks.

Before you hook up the trailer and hit the road, make sure your vehicle is ready for the extra load.

Common towing issues we see every summer:
✔️ Cooling system failures
✔️ Overheating
✔️ Weak batteries
✔️ Worn belts and tensioners
✔️ Transmission concerns
✔️ AC performance problems

A quick inspection before your trip can help prevent costly breakdowns and ruined vacation plans.

At Nelson Performance, we provide complete maintenance, diagnostics, and repair services for GM V8-powered cars, trucks, and SUVs. Whether you're towing a camper, race car, boat, or work trailer, we'll help make sure your vehicle is ready for the season ahead.

Don't get stranded this summer—schedule your inspection before your next road trip.

📞 210-626-0278

06/03/2026

🔥 Another GMC back on the road!

This 2003 GMC Sierra came in with a misfire concern. After diagnosis, we cleaned the fuel injectors, replaced the oxygen sensors, and installed a new muffler to help restore proper performance and drivability.

Proper diagnosis is the key to solving misfire issues. Throwing parts at a problem can get expensive fast. We use real-world testing and experience to identify the root cause and get our customers back on the road with confidence.

Need help with a misfire, check engine light, or drivability issue? Give us a call.

📞 210-626-0278
📍 San Antonio, Texas
🔧 GM LS & LT Specialists

Hashtags

🚗💨🔧

06/02/2026

⚡ Electrical issues can mimic major engine problems if they aren't diagnosed correctly.

This 2014 Silverado came into the shop with injector-related drivability concerns. After proper diagnostic testing, we traced the issue to a faulty driver-side injector harness.

✅ Performed electrical diagnostics
✅ Located failed injector harness circuit
✅ Replaced driver-side injector harness
✅ Verified proper injector operation

Parts replacement without testing can get expensive fast. Accurate diagnostics help identify the actual failure so the repair is done right the first time.

At Nelson Performance, we don't guess—we diagnose. 🔍

📞 210-626-0278
📍 San Antonio, Texas
🔧 GM LS & LT Specialists

Hashtags

06/01/2026

⚠️ Check Engine Light On? Poor Fuel Mileage? Don't Ignore the Warning Signs.

This 2012 Silverado came to us with drivability concerns and a check engine light illuminated. After proper testing and diagnosis, we confirmed both upstream (front) O2 sensors were providing inaccurate feedback to the ECM.

The oxygen sensors play a critical role in fuel control. When they begin to fail, they can cause poor fuel economy, reduced performance, and incorrect air/fuel mixture calculations.

✅ Diagnosed the concern
✅ Replaced both upstream O2 sensors
✅ Cleared fault codes
✅ Verified proper operation

At Nelson Performance, we don't guess—we test. Accurate diagnostics save time, money, and unnecessary parts replacement.

If your truck has a check engine light, poor fuel mileage, or drivability issues, let our team pinpoint the problem and get you back on the road with confidence.

📍 San Antonio, Texas
📞 210-626-0278

05/31/2026

2016 Silverado 2500HD in for a Nelson Performance custom tune. 🔥

These trucks respond incredibly well to proper calibration when the tuning is built around how the truck is actually used. Better throttle response, cleaner shifting, improved drivability, and more consistent power delivery throughout the RPM range make a huge difference behind the wheel. 👊

One of the biggest improvements customers notice is how much more responsive the truck feels during normal driving and towing situations. Reduced pedal lag, improved transmission behavior, smoother part-throttle operation, and better downshift strategy help the truck feel stronger and more refined everywhere you drive it.

Whether the truck is used for towing, daily driving, or running larger wheels and tires, custom tuning helps bring everything together so it performs the way it should. 💪

This Silverado left driving smoother, stronger, and far more enjoyable on the street.

📞 210-626-0278
🌐 [www.nelsonperformance.com](http://www.nelsonperformance.com)

05/30/2026

This 2004 Suburban came to us running terrible after work performed at another shop. Poor drivability, rough running, and multiple issues had the customer frustrated and looking for answers.

At Nelson Performance, we don’t guess — we diagnose. Using our smoke machine, we quickly tracked down a major vacuum leak that was causing serious performance problems. Once the leak was identified, we replaced the intake manifold gaskets and continued working through the additional issues affecting reliability and drivability.

Repairs completed included:
✔️ Intake manifold gaskets
✔️ Thermostat housing
✔️ Water pump
✔️ Battery terminals
✔️ Throttle body harness

Proper diagnostics matter. A vacuum leak can create all kinds of symptoms including rough idle, lean conditions, poor throttle response, misfires, and unstable drivability. The smoke test allowed us to pinpoint the exact failure instead of throwing random parts at the truck.

Now this Suburban is back on the road running the way it should.

📍 Nelson Performance
📞 210-626-0278
🌐 Nelson Performance

05/29/2026

This 2008 GMC Sierra came to us after a 5.3L to 6.0L / 6L90E swap completed by another shop. Once the hard parts are installed, that’s where the real work begins. Proper calibration is what brings a swap together and makes it drive the way it should.

We handled the tuning side to get the combination working correctly together — engine, transmission, drivability, shift strategy, and overall performance. A swap can have all the right parts, but without the correct tune you can still end up with poor shifting, drivability issues, throttle response problems, or check engine lights.

This Sierra left running cleaner, shifting smoother, and driving the way a properly completed swap should.

At Nelson Performance we specialize in GM tuning, diagnostics, drivability, and custom combinations from mild builds to full performance setups.

📞 210-626-0278
🌐 www.nelsonperformance.com

05/28/2026

This 2001 Escalade was towed into Nelson Performance after the customer installed a new engine and immediately ran into major drivability issues. The truck was stuck in REP (Reduced Engine Power) mode and barely driveable. 🔥

Instead of guessing and throwing parts at it, we went straight into diagnostics. After testing and inspection, we traced the problem to a heavily restricted dirty injector causing poor fuel delivery. The injectors were cleaned, serviced and reinstalled, restoring proper operation and getting the Escalade back out of REP mode. 👊

While the truck was here, we also took care of several other issues to get it fully sorted out:
✔️ Replaced the brake master cylinder after the customer lost braking pressure
✔️ Installed a new belt tensioner and pulley
✔️ Replaced both drive belts
✔️ Finished everything off with a Nelson Performance tune

This build is a perfect example of why proper diagnostics matter. Even with a brand new engine, a small issue like a restricted injector can create major performance and drivability problems. Test it. Verify it. Fix it right. 💪

Now this Escalade is back on the road running strong and driving the way it should. 🚙💨

📞 210-626-0278

05/27/2026

Customer installed headers on this 2019 Camaro SS manual transmission and brought it to us for the important part — the calibration. 👊

A proper tune after header installation is critical for drivability, throttle response, air/fuel correction, and getting the most out of the setup without lighting the dash up like a Christmas tree. 🔥

This Camaro left with a full custom street tune from Nelson Performance and is ready to row gears the way it should. 🏁

No dyno queen numbers. Just real-world performance, drivability, and results you can feel every time you hit the throttle. 🇺🇸

📍Nelson Performance
📞 210-626-0278
🌐 www.nelsonperformance.com

05/26/2026

Header install created a steering shaft clearance issue on this 2017 Cadillac Escalade.

The factory rag joint style shaft was making contact after the headers were installed, so we upgraded to a later style shaft for additional clearance and a cleaner fit.

Small changes like this can make a huge difference in drivability, noise prevention, and long term reliability. This is why details matter on custom performance work.

At Nelson Performance we don’t just bolt parts on — we make sure everything works together correctly. 🔥

📍 Nelson Performance
📞 210-626-0278

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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