Regeneration of the Tatra 815, Force and Phoenix injection pump - Motorpal PV8A, Paccar MX-13

Tatra – an icon of truck engineering with a unique drive system architecture

Tatra trucks are some of the most recognizable heavy vehicles in the world. The characteristic skeletal frame with a central support pipe and independently suspended swing axles is a Tatra patent that has been used since 1942 and remains unchanged to this day. These vehicles are used by the army, fire brigade, technical services, open-pit mines and special transport companies in dozens of countries on all continents. In Poland, the Tatra Mountains include, among others: in units of the Polish Army (T815-7 series), the State Fire Service (815 Force) and in the construction and mining sectors.

The heart of every Tatra is a combustion engine with an injection system - determining power, reliability and compliance with emission standards. A-Core Diesel Service regenerates both classic Motorpal mechanical injection pumps used in T3C and T3D 928 series engines, as well as common rail injectors of the Paccar MX-13 engine from new generations of Phoenix. Each regeneration is documented with a test report on the test bench.

Generations of Tatra engines - overview of injection systems

The history of Tatra truck engines includes several distinct generations, each with a different injection system:

T3C-928 and T3D-928 engine – Motorpal PV6A / PV8A (Tatra 815, 815-2, Force)

The heart of most classic Tatra trucks is an air-cooled V8 engine with a capacity of 12,667 cm³, produced in the following versions:

• T3C-928-xx – Euro 3, Motorpal mechanical injection pump, without SCR
• T3D-928-xx – Euro 4/5, mechanical Motorpal pump + independent SCR system (AdBlue), electronic regulator

Injection pumps in both versions are in-line multi-piston Motorpal units of the PV6A or PV8A type (8 piston sections) with an RV or RN speed controller. The pump is identified based on three nameplates: on the pump body (marking PV...), on the feed pump and on the regulator cover.

Paccar MX-13 engine – Common Rail Bosch CP4 + CRI3 (Tatra Phoenix)

The Tatra Phoenix series uses a civilized 6-cylinder in-line Paccar MX-13 engine with a capacity of 12.9 l in the Euro 6 standard. It is a design with a common rail system operating at a pressure of up to 2,500 bar - one of the highest pressure levels used in trucks. The high pressure pump is Bosch CP4 (two units in the engine block) and the injectors are Bosch CRI3 with solenoid valves.

Cummins and Caterpillar engines – export and special versions

Some export versions of the Tatra Force and T815-7 are equipped with Cummins ISM / ISX or Caterpillar C13 engines - especially in orders for the US army, Australia and other NATO countries. The injection systems of these engines are Cummins XPI and Caterpillar HEUI/C-ACERT, respectively.

Motorpal PV8A injection pumps – structure and catalog numbers

Tatra model	Engine	Motorpal pump	Regulator type	Euro
T815 S1 / S2 (1983–1994)	T3A-928 / T3B-928	PV8A-1xxx (6-sec.)	RV (mechanical)	pre-Euro
T815-2 (1994–2000)	T3C-928-xx E2	PV8A-1xxx / PV8A-2xxx	RV / RVD (mechanical)	Euro 2
T815-2 / Force (2000–2006)	T3C-928-xx E3	PV8A-3xxx	RN (electronic)	Euro 3
T815-7 Force (2006–2012)	T3D-928-xx E4	PV8A-4xxx + SCR	RN-D (el. + AdBlue)	Euro 4
T815-7 Force (2012–2018)	T3D-928-xx E5	PV8A-5xxx + SCR	RN-D (el. + AdBlue)	Euro 5
T815-7 (special versions, military)	T3C-928-xx (no standards)	PV8A-1xxx / PV8A-3xxx	RV / RN	no standard
Phoenix NT (from 2012)	Paccar MX-13 E6	Bosch CP4 (2x)	CR EECU controller	Euro 6

Identification note: The exact part number of the Motorpal pump is engraved on a plate mounted on the pump body and begins with PV (e.g. PV8A-1110L275, PV8A-3070S, PV8A-4120S). Different versions of the T3C and T3D engine in different vehicle configurations (military, fire-fighting, construction, export) may have different numbers, so before ordering regeneration, please always provide the number from the plate.

Paccar MX-13 injectors – Common Rail in Tatra Phoenix

Tatra model	Engine	CR pump	Injector	Bosch no.	Euro
Phoenix NT 6x6 / 8x8	Paccar MX-13 Euro 6 (480/510 HP)	Bosch CP4 (2×)	Bosch CRI3-20	0 445 126 068 / 0 445 126 069	Euro 6
Phoenix TT (semi-trailer)	Paccar MX-13 Euro 6 (430 HP)	Bosch CP4 (2×)	Bosch CRI3-20	0 445 126 066 / 0 445 126 067	Euro 6

The most common symptoms of injection pump failure in Tatra 815 and Force

Tatra trucks work in extremely difficult conditions - off-road, deep snow, desert heat, working in the mine around the clock. The injection system with a Motorpal PV8A mechanical pump is relatively simple and resistant, but after 200,000-400,000 km or many years of operation, it requires regeneration.

Symptoms indicating a worn Motorpal pump

• Loss of power and lack of thrust on hills - T3C/T3D engine does not achieve full power under load, especially when exceeding 2,500 rpm
• Increased fuel consumption – visible increase by 10-20% with the same operation
• Thick black smoke from the exhaust pipe – especially when accelerating and at full throttle
• Difficult cold start – poor starting dose at low temperature (below -10°C)
• Uneven engine operation – "jerking" at constant speed or idling
• Fuel leakage from the pump body – damaged piston seals or housings
• Incorrect idle speed – RN/RV regulator does not maintain stable speed
• Ratter from the engine synchronous with camshaft rotation – section pusher damaged

Error codes T3D-928 (RN-D + SCR electronic controller)

Error code	Description	Applies to
SPN 94 FMI 1	Fuel pressure before the pump – too low	T3D / T3C
SPN 190 FMI 0	Engine speed above RN-D controller range	T3D E4/E5
SPN 1569 FMI 31	Torque limitation - controller thresholds exceeded	T3D E5
SPN 3361 FMI 1	AdBlue – SCR system: dosing error (secondary to the pump)	T3D E4/E5
SPN 636 FMI 2	Pump shaft rotation sensor - synchronization	T3D RN-D
SPN 2791 FMI 9	Dose control - value outside the controller range	T3D E5

Motorpal PV8A pump regeneration – full A-Core procedure

Stage 1 – Plate reading and pre-test

Before disassembly from the truck or before shipping, we read the three nameplates of the pump. The PV... number from the pump housing, the feed pump number and the RV/RN controller number allow us to clearly identify the pump version and load the appropriate calibration parameters. The pre-test on the Bosch EPS 200 / EPS 815 test bench records: idle dose (750-850 rpm), rated dose (2,000 rpm), cold correction dose (richer starter), coasting dose and regulator characteristics.

Step 2 – Disassembly and wear assessment

Disassembly of the Motorpal PV8A pump in clean conditions. We control:

• Piston clearance in the cylinder of each of the 8 sections (Motorpal standard: less than 2 μm)
• Condition of delivery and suction valves – tightness and closing time
• Pushers and camshaft - drive cams wear
• RV / RN regulator – springs, bushings, levers and muffs
• Feed pump – pressure and flow
• Automatic injection regulator (centrifugal) – advance angle range
• Drive shaft oil seals and protective caps

Stage 3 – Replacing components and selecting Motorpal OEM

We use only original Motorpal components or certified OEM parts: piston-cylinder sets (precision pairs in clearance classes 2, 3, 4 μm), delivery valve sets, shaft oil seals, regulator repair kits and feed pump elements. Each piston-cylinder pair comes from the same tolerance range - cross-assembly is not allowed.

Stage 4 – Calibration on the test bench

After assembly, the pump goes to the testing table. Calibration includes:

• Setting the injection advance angle (according to the T3C/T3D engine plate)
• Dose compensation between 8 sections (tolerance: ±2% from the nominal dose)
• Calibration of rated dose and idle speed
• Adjustment of the maximum speed of the regulator (RV: mechanical springs; RN: electronic map)
• Starting dose test and feeding pump check

Stage 5 – Post-test and report

After calibration, the pump undergoes an identical test as the pre-test. Results must be within Motorpal factory standards and T3C/T3D engine parameters. The customer receives a printout of the pre/post report with the pump's PV number, regeneration date and technician's signature.

Specifications of the website for the army, State Fire Service and special services

A significant part of Tatra trucks used in Poland are vehicles of the Polish Army and State Fire Service. The service of these vehicles has its own specificity:

• T815-7 and Force 6x6 / 8x8 military vehicles – often equipped with T3C engines (without emission standards) or T3D Euro 4/5 engines with RN-D regulators. Many vehicles have very high mileage and off-road use
• Tatry PSP (fire brigade) – T815 Force series vehicles as carriers for GCBA and GBA bodies. Operation in combat readiness conditions, irregular starts, cold start after long downtime
• Mining and construction vehicles – sometimes operated without mileage limits, in dusty conditions and at extreme temperatures

A-Core Diesel Service accepts orders from military units, construction plants and machine operators. For institutional orders, it is possible to issue a VAT invoice with the description "regeneration of the injection pump, serial number: PV..., vehicle: Tatra T815 Force, side number:...". Delivery time: 5-7 business days. Shipping service: all over Poland.

Supported Tatra models and configurations

• Tatra 815 S1 / S2 / S3 – semi-trailers and construction trucks, T3A/T3B/T3C engine, pre-Euro–Euro 2
• Tatra 815-2 – 1994–2000, T3C Euro 2, Motorpal PV8A-2xxx
• Tatra 815 Force – from 2000, T3C Euro 3 and T3D Euro 4/5, 4×4, 6×6, 8×8 configurations
• Tatra T815-7 – military and special, T3C/T3D, skeleton frame with new cabin
• Tatra Phoenix NT – civilian, Paccar MX-13 Euro 6, CR Bosch CP4/CRI3
• Tatra Phoenix TT – tractor unit, Paccar MX-13 Euro 6
• Tatra T148 / T813 (classics) – older models with mechanical pumps, on request

Why is it worth regenerating the Motorpal pump instead of buying a new one?

The new Motorpal PV8A injection pump is a rarely available part - the manufacturer supplies it mainly through an authorized network of Czech service centers or as an element of an engine overhaul. Availability on the secondary market in Poland is limited, and importation from the Czech Republic is ongoing. Regeneration by a specialist service with testing table equipment offers a number of benefits:

• Restore factory parameters confirmed by test report
• Replace only those components that do not meet tolerances - without unnecessary costs
• 12-month warranty for regeneration
• Shorter delivery time than importing a new pump from the Czech Republic
• Possibility of documentation service for institutional units (army, State Fire Service)

Frequently asked questions - FAQ

How to identify the type of Motorpal pump in my Tatra?

Look for a metal plate embossed or engraved on the side of the pump body. The designation starts withPV(e.g. PV8A-3070S or PV8A-4120S). The number after the dash indicates the calibration version. Please take a photo of the plate and send us the photo when ordering - it will be enough for identification.

Is it possible to regenerate the pump from Tatra Euro 3 to Euro 5 (T3C → T3D)?

No – Euro 3 (T3C, RV controller) and Euro 4/5 (T3D, RN-D controller with electronic control) pumps are different designs with different calibration maps. We regenerate each pump to the parameters of its own engine - we do not convert between standards.

Is calibration via T3D computer diagnostics necessary after pump regeneration?

In T3D engines with an RN-D regulator, the mechanical pump cooperates with an external electronic controller. Mechanical regeneration of the pump does not require reprogramming the controller, but we recommend checking the base values ​​through the Tatry diagnostic software (TRS or VCDS-compatible) after installation.

Do you support Tater T148 and T813 pumps (old trucks)?

Yes - for classic Tatra T148 and T813 models with Motorpal or Bosch PE mechanical in-line pumps, we perform diagnostics and regeneration after prior arrangement of parts availability. Please contact us before shipping.

Can I bring the Tatra directly to the service center?

Yes – stationary service in Knurów, Silesia. We accept trucks, military vehicles and work machines directly. In the case of non-mobile vehicles (failure in the field) - logistics can be agreed in advance.

How long does it take to regenerate a set of 8-section PV8A pump?

Standard time is 5-7 business days from delivery of the pump. In the case of an urgent order (immobilized vehicle, military mission or PSP alarm), we can shorten the time to 3 business days - please contact us by phone before shipment.

Do you support Paccar MX-13 injectors from Tatra Phoenix?

Yes - Bosch CRI3-20 injectors from the Paccar MX-13 engine used in Tatra Phoenix are serviced by us. Full regeneration with pre/post test on the Bosch EPS 815 table and report.

Contact and location

A-Core Diesel Service
Bartłomiej Biernat
Knurów, province Silesia
Tel.: +48 504 511 170
Reception hours: Monday - Friday, 8:00 a.m. - 4:00 p.m.

Stationary and shipping service. We serve the army, State Fire Service, construction, mining and transport companies. Free quote after initial identification of the pump's PV number or vehicle's engine number.