1989-1993 Dodge 5.9L Cummins Fuel Injectors

Injectors on the 1989-1993 Ram 5.9L Cummins

The first-gen Cummins is direct injected and fully mechanical. The Bosch VE44 rotary pump makes the injection pressure and sends fuel through six individual steel lines, one to each mechanical Bosch pop-off injector. There is no electronic control of the injectors at all. The Bosch OE injector listed for the first gen is the KDAL 59 P5, Bosch 0432131837, sold on core exchange. Stock injectors are not the same across all five years, though. Intercooled trucks, built from mid-1991 on, take different stock injectors than the non-intercooled trucks before them. Return fuel leaves the injectors through banjo-bolted return lines whose bolts and washers are shared across 1989-1998 12-valves.

What fails and why

Injector wear on a first gen is mostly a very-high-mileage story, and the evidence is anecdotal. A 1993 D250 survivor reached 620,000 miles on its original long block, and its injectors were pop-tested when its VE was overhauled. On engines with that kind of mileage, the symptoms owners connect to worn injectors and weak pop pressure are smoke, rough idle, uneven cylinder contribution and lost economy. Fuel plays a part too. The injectors and the VE were designed for higher-sulfur fuel, and the lower lubricity of ULSD is tied to accelerated injector wear and sticking over time.

Stock replacement vs. upgrade

For a working truck, go stock: new Bosch OE KDAL 59 P5 units or stock-replacement injectors matched to whether the truck is intercooled. That keeps fueling where the factory set it.

For a built truck, staged injector sets exist for 1989-1993 VE trucks, including Dynomite Stage 1 through 3 and Economy series sets. Staged injectors need a matching pump and supply, so plan the lift pump and injection pump along with them. Diesel Army rates the VE as topping out around 500 hp, so a high power target means planning a P7100 conversion as well. Staged sets are sold alongside 7 mm-to-9 mm injector sleeves and an install kit, and a 12-valve injector puller is sold for 1989-1998 engines.

What we carry

• Dynomite Diesel DDP8993 12-valve nozzle set for 1989-1993.
• Dynomite Diesel 12 Valve Series injector set for 1989-1993.
• S&S Diesel Motorsport injector feed tubes, titled for 2003-2007 5.9L Cummins trucks.

Comparing sets or shopping another truck? Browse all injectors.

Fitment notes

• Intercooler first. Vendors often title stock intercooled-truck injectors 1990-1993, but intercooling began mid-1991. Match injectors to whether the truck has the factory intercooler, not to the year on the listing.
• Nozzle set or injector set. They are different purchases. Read the product page to see exactly what comes in the box before you order.
• Feed tubes titled for later trucks. The S&S feed tubes here are titled for 2003-2007 5.9L Cummins, not 1989-1993. Confirm fitment with the checker or a call before ordering.
• Match the system. Pump, supply, injectors and intended power level should line up. Staged injectors on a stock supply side are a mismatch.

Frequently asked questions

How do I know if my first-gen injectors are worn?

Owners of very high-mileage trucks connect worn injectors with smoke, rough idle, uneven cylinder contribution and lost economy, though the evidence is anecdotal. A pop test tells you more than guessing; the 620,000-mile survivor had its injectors pop-tested during a VE overhaul.

Which stock injector does my truck take?

The Bosch OE injector listed for the first gen is the KDAL 59 P5 (Bosch 0432131837), sold on core exchange. Stock replacements for intercooled trucks are listed separately from non-intercooled ones, and intercooling began mid-1991, so check for the factory intercooler before you order.

Can I run staged injectors on the stock VE pump?

Staged sets are made for 1989-1993 VE trucks, but they need a matching pump and supply. Match the injection pump, lift pump and injectors to the power level you plan to run. Diesel Army puts the VE's ceiling around 500 hp; past that, the P7100 conversion comes into play.

What install parts and tools go with an injector job?

For 1989-1998 12-valves, 7 mm-to-9 mm injector sleeves and a 12-valve injector puller are sold, and staged sets come alongside sleeves and an install kit. Return-line banjo bolts and washers are shared across 1989-1998 12-valves. When the job is done, bleed the air out with the hand primer.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.