[Classicpain]

Trying to troubleshoot the mysterious (yet common, if I go by past posts) intermittent surging, stumbling, idling issues I'm having on my 93 LWB, and I'm wondering if the IACV can have an effect at higher engine speeds. I replaced it less than 2k miles ago, doesn't seem like that COULD be the problem.

 

[Mikieman]

If your stumbling is after engine warms up
I would think it is a vacuum problem
Probable connected to your throttle body
Gaskets and or your spark modulator heating up if it is still connected to your distributor

 

[Range123]

Listen for hissing around the brake servo to. vacuum loss there will throw the symptoms you have but its often overlooked as the cause. Just replaced mine £102 GBP for the whole unit as nothing is servicable. Also check the vac hose from the servo to the plenum also often overlooked.:shock:

After market steppers can be hit and miss.

 

[grnole]

the IACV on my 95 RRC caused the truck after about 5-10min of driving to start surging and dying. (at any speed) It would recover, and then act somewhat normal. Upon changing it, I literally had to disconnect the battery, and touch the terminals together to unload all the saved config from the diodes and etc. Just swapping the part did not do anything. (just and FYI from my experience)

 

[95classiclwb]

Trying to troubleshoot the mysterious (yet common, if I go by past posts) intermittent surging, stumbling, idling issues I'm having on my 93 LWB, and I'm wondering if the IACV can have an effect at higher engine speeds. I replaced it less than 2k miles ago, doesn't seem like that COULD be the problem.

you could keep on throwing parts at it but with out actually looking at numbers of engine performance you're chasing a ghost and wasting time and money.
there is a program called rover gauge which software to read 14 cux efi performance.

 

[Range123]

Yep Rover Gauge is actually quite good for the price.

Over on bay of E in UK it is £35.00 inc the specific connection cable.

The instructions are ok. I brought one and have used it - its worth a go.
https://www.ebay.co.uk/itm/Range-Ro...558259?hash=item33eebae6b3:g:3-cAAOSw6qpa157K