Why won't my Isuzu Hombre start, or why does it run rough?

Short answer: The Hombre is a Chevy S-10 underneath, so S-10 parts and advice fit. If it died on the road and now cranks with good fuel pressure, test for spark properly, with the tester grounded to the engine. No spark after new ignition parts means checking the wiring and whether the camshaft still turns (a slipped timing chain). If it accelerates rough with P0300 (random misfire) and P0172 (running rich), replace old plug wires and check the coil packs.

Symptom: The truck had hard starts for a month, died while driving and now cranks without starting. Or it idles fine but stumbles when you accelerate.

What to check first

1. Confirm fuel pressure. One owner had 41 psi after a new pump and filter.
2. Test for spark the right way: a spare plug on a plug wire, held against the engine block, not the battery terminal.
3. No spark? Check the camshaft turns while cranking (look through the oil filler) and check wiring after any ignition work.
4. Rough acceleration? Get the codes. P0300 plus P0172 often means a misfire is leaving unburned fuel.
5. Test coil pack and plug wire resistance, and replace wires that are original or questionable.

Likely causes

1. Ignition problem (wiring, module or a part installed wrong). The 1996 truck had no spark after many new parts, and the owner suspected something done during the repairs.
2. Slipped timing chain. Raised in the thread for a truck that died while driving with hard starts beforehand.
3. Worn plug wires or coil packs. Behind a random misfire in the 1997 thread.
4. Failing fuel pump. The 1996 truck's original problem.

What it usually costs

No owner posted a final bill. Plug wires and coils are inexpensive compared with a timing chain job, so rule them out first.

Is it safe to keep driving?

Rough running is okay for short local trips if the check engine light isn't flashing. If it's flashing, stop driving. A truck that died once can die again in traffic. Verify with a mechanic.

DIY or shop?

DIY for spark tests, plug wires and coils. Timing chain work is a shop job for most owners.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Isuzu Hombre: 97V208002 (1998-1998 model years, electrical system). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• NHTSA complaints: 15 keyword-matched complaints for Isuzu Hombre 1996–2000 (of 122 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-25; keywords: won't start or crank, no start, click, starter, ignition switch, stall, dies, crank, spark, misfire, fuel pump, rough). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 96 Isuzu hombre 2.2L MFI crank, no start on Car Talk, a 1996 Hombre had hard starts for a month, died on the road, and wouldn't start even after a new pump and filter (41 psi), coils, plugs, wires, ignition module, battery, crank sensor and regulator. Members coached a proper spark test, said to check the camshaft turns, and raised a slipped timing chain. The owner later confirmed no spark and wondered if something went wrong during the repairs.
• In 1997 Isuzu Hombre p/u accellerates rough on Car Talk, a 1997 Hombre four-cylinder idled smoothly but stumbled when accelerating. The owner had already replaced the plugs, wires and fuel pump. A parts store scan showed P0172 and P0300, and the staff suggested coil packs. Members said to test the coil pack and wire resistance using free online repair manuals, and that replacing plug wires that are original or questionable is a cheap step.

Quick tip

When you've replaced everything and it's worse, retrace your own work. Connectors left unplugged and parts in the wrong order are more common than a second failure.

Vehicle focus: 1996–2000 Isuzu Hombre (2.2L four and 4.3L V6), a rebadged Chevrolet S-10.

Safety / mechanic note

A flashing check engine light can mean catalytic converter damage; stop driving. Verify with a mechanic.