Engine surge

#1

What can I try to stop my isuzu’s engine surge?

#2

Model?
Model year?
Engine size/type?
Odometer mileage?
When did the engine last have basic maintenance (plugs, filters)?

Does it surge at idle?
Does it surge while you are driving?
Does it surge when the engine is hot?
Does it surge when the engine is cold?

#3

Here are a couple of possibles: vacuum leak or perhaps a faulty throttle position sensor (maybe just loose).

#4

92 Isuzu pickup
2.2 liter
approx 134,000 miles
basic maintenance. 2,000 miles ago

surges at idle, more when it warms up.

#5

The possibilities on a 17 year old engine are really numerous, but I would check all vacuum lines thoroughly. Even though this truck does not have many miles on the odometer, rubber parts will have deteriorated badly during that 17 year period, and as a result, a cracked vacuum hose would be my major suspect.

Incidentally, if those 134,000 miles are accurate, that means that this truck is driven–on average–less than 8k per year. The OP should bear in mind that it needs to be maintained on the basis of elapsed time, NOT on the basis of odometer mileage. In other words, instead of changing the oil every…let’s say…4,000 miles, he should be changing the oil every 4 months.