Feb 20, 2020 · Truck idles low and won't restart after warm. 2.5L ('98-'01) Engine starts quick, idles mint, then dies. 03 ranger edge revs high at start and idles rough. I have a slightly modified 1992 4.0, bigger throttle body, injectors and MAF housing. I had the original setup working before it came out and went into the...

Jul 22, 2018 · Symptoms: rough shaky "missing idle" lack of power under 2800 rpm, poor fuel mileage. sometimes it is smooth as butter and runs with great power, sometimes sitting in the drive through and idling it catches itself and will idle up and smooth out, sometimes it wont.

Jan 15, 2022 · Keep fighting the good fight, 4e is excellent and it deserved a better chance than the one it got. Yeah, I keep count and am surprised that some old posts here and on GiantITP still get so many requests.

May 1, 2018 · Whenever you unplug your iac the engine should idle way down and almost stall. Idle on the 4.0 tps is usually around .94-96v. If it is on .8v then it should be idling a lot lower. If you unplugged your iac and it does nothing then you have a vacuum leak. Change your pcv valve and see what happens. A smoke test won't tell you when they are bad.

Aug 16, 2008 · 4.0L Rough Idle - Tried everything... any more ideas? 2004 WJ w/ 4.0L and 4x4. I have replaced, plugs, IAC, TPS, Crank Position Sensor, removed and completely cleaned throttle body (with sensors out). I have done an oil change, …

Jan 15, 2025 · Vortec engines don't idle perfectly smoothly, in part because they idle too slowly (probably for emissions reduction). Put a tune on the engine and raise the idle speed to 650 in park and in gear. It really helps smooth things out. '13 SLE 4x4 Ext Cab 5.3 6sp 3.42 G80 Z82 Z60. Bought new.

Dec 6, 2016 · Like seafoam or chevron techron. Those are the only two I use personally. The idle air control valve could be cleaned as well. They get all gummed up with carbon and will cause a rough idle. If it's not a big difference in the idle but enough for you to notice it, every GM 4.8 or 5.3 truck I've owned has had a fluctuation at idle.

Sep 27, 2011 · I have read a few threads with similar issues but non like mine, before my tranny blew my idle was struggling to hold and was jumping from 100rpm to 200rpm and felt like it was going to stall when I was stationary.

Mar 31, 2025 · The rev at idle should be 625 RPM to 675 RPM and can be adjusted as "Base Idle" on the side of the throttle body is a grub screw about 15 mm long that adjusts the idle, piss your mechanic off and find someone who knows what they are doing.

Oct 21, 2009 · The usual suspect for high idle is in most cases on your 1997 4.0 is a dirty and or sticking IAC (idle air control ) valve and I would start with removing it and try cleaning it real well with carb cleaner.