# 1992 Isuzu Pickup surging **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** isuzu, pickup\ **Created:** [July 24, 2018, 11:21pm UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640 "2018-07-24T23:21:04Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![ridesimple](https://avatars.discourse-cdn.com/v4/letter/r/7ba0ec/32.png) [@ridesimple](https://community.cartalk.com/u/ridesimple)\ **Post date:** [July 24, 2018, 11:21pm UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/1 "2018-07-24T23:21:04Z")
Anyone have advice on a 2.6L 4cyl. that is “surging” normal idle, then down to nearly dying then back up. The engine and fuel injectors and nearly everything else has been replaced, but the surging is completely unaffected. My mechanics and I are at a loss. In advance, thanks. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [July 25, 2018, 2:00am UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/2 "2018-07-25T02:00:18Z")
Idle rpm wandering/too high idle rpm can be tough to diagnose. Usually it is some kind of air leak allowing excess air into the intake manifold. Possibilities: Idle speed throttle actuator, idle up valve (increases idle when AC turned on, etc), intake ducting air leak, intake manifold air leak, egr leak, vacuum hose leak, vacuum device leak e.g. brake booster, PCV system leak or faulty pcv valve, Oil filler cap not sealing, oil dipstick fell out. First monkey around with the controls that you can affect, see if any of them have an effect. AC on/off, headlights on/off, rear window defroster on/off, anything that might tend to bog down the engine at idle. After that I’d focus on the idle speed actuator, brake vacuum booster, or throttle body or intake manifold gaskets. Sometimes starter fluid can be sprayed near suspected air leaks. If the rpm goes up, there’s a leak there. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 25, 2018, 2:08am UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/3 "2018-07-25T02:08:46Z")
The Idle Air Control valve might be hunting for the proper idle position. [https://www.rockauto.com/en/catalog/isuzu,1992,pickup,2.6l+l4,1176678,fuel+&+air,idle+air+control+(iac)+valve,6072](https://www.rockauto.com/en/catalog/isuzu,1992,pickup,2.6l+l4,1176678,fuel+&+air,idle+air+control+(iac)+valve,6072) Tester ---
**Author:** ![ridesimple](https://avatars.discourse-cdn.com/v4/letter/r/7ba0ec/32.png) [@ridesimple](https://community.cartalk.com/u/ridesimple)\ **Post date:** [July 25, 2018, 4:56am UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/4 "2018-07-25T04:56:50Z")
Thank you. This problem is so iffy. Sometimes fails and sometimes normal. You’re advice is so welcome thank you. Joe ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [July 25, 2018, 3:57pm UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/5 "2018-07-25T15:57:48Z")
Clean the throttle body and adjust the throttle position sensor. ---
**Author:** ![ridesimple](https://avatars.discourse-cdn.com/v4/letter/r/7ba0ec/32.png) [@ridesimple](https://community.cartalk.com/u/ridesimple)\ **Post date:** [July 25, 2018, 9:01pm UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/6 "2018-07-25T21:01:26Z")
Will do and I cannot thank you enough ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [July 26, 2018, 12:28am UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/7 "2018-07-26T00:28:30Z")
fyi, when my Corolla of similar vintage developed that problem a couple years ago, turned out to be a problem w/the idle air control mechanism. My solution was to just disable that function. The downside is I have to keep my foot on the gas pedal a little in very cold weather for the first couple of minutes after the first start of the day to prevent stalling at the first stop sign. But it doesn’t get that cold in San Jose even in the winter, so not much of a problem for me. ---
**Author:** ![ridesimple](https://avatars.discourse-cdn.com/v4/letter/r/7ba0ec/32.png) [@ridesimple](https://community.cartalk.com/u/ridesimple)\ **Post date:** [July 26, 2018, 8:23pm UTC](https://community.cartalk.com/t/1992-isuzu-pickup-surging/121640/8 "2018-07-26T20:23:48Z")
Thank you so much. This may help.