VE Injector Calibration & Bosio Nozzle Mounting Service — Digital Flow-Matched, 5 Pressure Stages

 What it is
This is a digital calibration and nozzle-mounting service for VW VE-pump diesel injectors (ALH, 1Z, AHU engine families). KermaTDI states this is the only correct way to properly set up new Genuine Bosio nozzles for full performance — nozzles installed without this calibration are not expected to perform to spec.

You must order nozzles separately
This service does not include injector nozzles. You need to separately add a set of Genuine Fratelli Bosio nozzles to your order — the service is the labor/calibration, not the parts.

Pressure Setting Stages — pick one at checkout

Increasing flow above Standard settings raises EGT incrementally, since fuel delivery occurs over a slightly longer window. Beyond Stage 4, KermaTDI generally recommends stepping up to a higher-flow nozzle rather than pushing flow settings further. These settings are mechanically set during the injector rebuild process — the ECU cannot adjust them — and can be re-set later without modifying or damaging the nozzle.

How the service works — two options

1. Send in your injectors: You'll receive a processing form with a shipping address after ordering. Downtime depends on shipping and turnaround.
2. Hot Swap Program: KermaTDI ships you a pre-mounted, pre-calibrated set of injectors first, so your car isn't down while waiting. You then return your original injectors as the core.

Hot Swap Program — full terms

• Requires a $600 core deposit at time of purchase (select "HOT SWAP" in the deposit option)
• Full deposit refunded once your original injector set is received in serviceable condition — no hidden fees
• A "complete set" means injectors from cylinders 1, 2, 3, and 4. The #3 injector is expected without its T return nipple and banjo bolt.
• Injectors must be returned unopened, with nozzles still installed, to avoid losing internal components
• "Serviceable condition" means no vice-grip marks or surface damage to bodies, return nipples, or threads. The #3 injector's sensor wire must have zero damage, fraying, or tearing — any damage there allows KermaTDI to retain the full deposit.
• Heavily fouled injectors (common with waste vegetable oil or high-concentration biodiesel use) may incur a $50 cleaning surcharge, or in some cases may not be cleanable to a usable standard at all
• Injectors must be removed using a slide hammer (pulled up and out of the head) — this is the method KermaTDI recommends to avoid damage during removal; a low-cost extractor tool is available for purchase
• Deposit is forfeited after 90 days if the core hasn't been returned and no arrangement has been made
• If your injectors are damaged beyond use, KermaTDI also sells complete new injector sets as an alternative

Critical fitment detail — #3 injector wire connector differs by year
1996–2002 vehicles use a square plug on the #3 injector wire. 2003 vehicles usually use a D-shaped plug instead. You must specify your vehicle's year at checkout so KermaTDI sends the correct connector, especially for the Hot Swap program.

Technical basis for the service (for reference)

• Two-stage injectors meter fuel across separate pressure events per combustion stroke (each event as short as 1.5 milliseconds), which is why they can't be calibrated with older single-stage methods.
• Calibration uses digital pressure sensing certified to ASME B40.7-2005, accurate to ±0.5%, across a range exceeding 600 bar, sampling all pressure cycles within a 10-millisecond window at 0.068 bar resolution.
• Every new nozzle sold is digitally flow-validated before installation, sampling flow rate up to 400 times per second — comparable to dyno testing for nozzles.
• Regular nozzle spray-pattern evaluation matters because even ideal fuel filtration can't eliminate all particulate; peak nozzle pressures exceeding 2,000 bar mean any suspended particles erode the nozzle's precision-machined holes over time.

Common questions

Do I need to buy nozzles separately, or are they included? Separately — this listing is the calibration/mounting labor only. Add Bosio nozzles to your order to complete the purchase.

What's the difference between sending my injectors in vs. Hot Swap? Sending in means your car is down until your injectors are serviced and returned. Hot Swap ships you a ready-to-install set first (with a $600 refundable core deposit), so there's minimal vehicle downtime.

Which pressure stage should I pick? Stage 1 (standard/OEM) for stock or economy-focused builds. Stages 2–5 add 5%, 10%, 15%, and 20% more main injection volume respectively, for progressively more performance, with EGT increasing incrementally at each step.

Will I get my full $600 Hot Swap deposit back? Yes, if your returned injectors meet the serviceable-condition standard — undamaged bodies/threads and an undamaged #3 injector sensor wire. Damage, or injectors fouled from WVO/high-biodiesel use, may reduce or forfeit the refund.

Does the connector matter for my Hot Swap injectors? Yes — specify your vehicle year at order time. 1996–2002 uses a square #3 injector plug; 2003 usually uses a D-shaped plug. Getting this wrong means the wrong part ships.