94 explorer mania swap

[RubyRanger16]

I just a did a manual swap on my 94 explorer and having some idle issues no I don’t have the manual ecu in it, it’ll idle at 1500rpm but then when I push the clutch in it’ll drop down to the correct idle 700rpm and stay there but the second i release it idle jumps right back up, unplugging the iac keeps the idle perfect, does this sound like I need the 94 manual ecu or is it something else?

 

[lil_Blue_Ford]

So, the auto computer is known to cause idle issues.

That said it also sounds like you have another issue. Vacuum leak, bad IAC, problem with the TPS, you’re gonna need to run some checks

 

[SenorNoob]

Good idle with the IAC unplugged says something is wrong to me. It should idle very low without IAC.

That said if it can be consistent while the clutch is pressed, maybe find the computer signal wire from the clutch and put it on a hidden toggle for adjustable idle? LOL

 

[RubyRanger16]

So, the auto computer is known to cause idle issues.

That said it also sounds like you have another issue. Vacuum leak, bad IAC, problem with the TPS, you’re gonna need to run some checks

I figured it be high my friends 94 with manual swap idle at 700-800 definitely not a vacuum leak if it idles fine with clutch in, I had a spare iac i replaced it still same issue

 

[RubyRanger16]

Good idle with the IAC unplugged says something is wrong to me. It should idle very low without IAC.

That said if it can be consistent while the clutch is pressed, maybe find the computer signal wire from the clutch and put it on a hidden toggle for adjustable idle? LOL

I have a spare iac I swapped it in still same issue, the truck would probably die if it was unplugged at the correct lower rpm, I also think it maybe computer since the check engine light also comes and goes

 

[lil_Blue_Ford]

I figured it be high my friends 94 with manual swap idle at 700-800 definitely not a vacuum leak if it idles fine with clutch in, I had a spare iac i replaced it still same issue

A vacuum leak could definitely still idle fine with the IAC unplugged. Unplugging it should make it idle super low or kill it. The best way to find a vacuum leak is with a smoke machine. 4.0s are notorious for a vacuum leak around the lower intake manifold.

My Choptop with a 90-92 Ranger 4.0 and the auto trans computer from then with a manual transmission idled around 1,000-1,200 RPM. That’s because that’s where it’s set for an automatic according to the computer.

Manuals should idle 7-900 rpm.

Parts quality anymore is garbage so just swapping an IAC doesn’t necessarily rule it out.

Throttle position also helps control idle. A bad TPS can cause idle issues. You can check its function with a multimeter, tons of threads on here that discuss how to do that.

 

[RubyRanger16]

A vacuum leak could definitely still idle fine with the IAC unplugged. Unplugging it should make it idle super low or kill it. The best way to find a vacuum leak is with a smoke machine. 4.0s are notorious for a vacuum leak around the lower intake manifold.

My Choptop with a 90-92 Ranger 4.0 and the auto trans computer from then with a manual transmission idled around 1,000-1,200 RPM. That’s because that’s where it’s set for an automatic according to the computer.

Manuals should idle 7-900 rpm.

Parts quality anymore is garbage so just swapping an IAC doesn’t necessarily rule it out.

Throttle position also helps control idle. A bad TPS can cause idle issues. You can check its function with a multimeter, tons of threads on here that discuss how to do that.

Yes it could, but when I push the clutch in the idle comes down to 800rpm so that seems like it rules out vacuum leak I’ll check again tonight I sprayed the vacuum line area on side of manifold to make sure nothing there, seems like it’s electrical, also the motor is fresh every gasket is new, I have another throttle body I’ll swap the sensor and see

 

[Doug904]

I just a did a manual swap on my 94 explorer and having some idle issues no I don’t have the manual ecu in it, it’ll idle at 1500rpm but then when I push the clutch in it’ll drop down to the correct idle 700rpm and stay there but the second i release it idle jumps right back up, unplugging the iac keeps the idle perfect, does this sound like I need the 94 manual ecu or is it something else?

You need a manual ecu to even start from. The automatics IAC tables are entirely different and the load variation is different from having a toque converter as opposed to a flywheel that duly disengages the load from the engine when stopped.