Yes but for a one minute test it will be fine.

What exactly is the wax element? Is it a part of the ISC or another part? I replaced my ISC several years ago but I still have a cold high idle of 1,800 +/- rpm. Over a minute or two the idle speed smoothly drops to around 750 but I sure don't like a cold start going immediately to 1,800.
Thanks,
Jim
Tulsa
'89 two door v6 auto

that's what Fasteddy calls a "fidle valve" (short for fast idle valve)so if you read here you will need to know that.

I guess it works like the thermstat...wax melts from hot coolant/water and allows the valve to open. wax hardens and closes the valve. Same principle with the fast idle valve, but I cant explain it well...might even be opposite... wax melts and closes valve.

It is near the ISC (or IAC) but not part of ISC

Ed

Thanks for the heads-up on that, but, after testing the ISC when I got home from work Fiday pm (25mile run) one for the coils in the ISC was open circuit. I re-tested saturday am & the same coil when tested wouldn't give a fixed reading, it constantly jumped all over the place. So I will order a replacement from the link in my first post, and while I wait on delivery I can search & read-up on how to set things up after the install.

I took the ISC out while testing and the pintle would rotate freely about 10degrees

I'll post an up-date later when I've repleced the ISC.

Thanks everyone for your posts, and if anyone wants a complete throttle body form a 95/96 auto just shout <img src="/forums/images/graemlins/kewl.gif" alt="" />

SteveN

Does the fast idle valve affect fast idle speed or does it just initiate a fast idle? If it just initiates a fast idle what would control the fast idle rpm?
Thanks,
Jim
Tulsa
'89 two door v6 auto

My NEW ISC arrived mid week, not bad 10 days from Oz, anyway
the 3 Mitsu diamonds are clearly visible in the moulding.

Planning to install over the weekend. Read what seems like 1000's of posts here & POCUK about setting the base idle correctly, a number refered to a connector on the bulkhead (firewall ?) but no pics.
From what I have read the procedure is:-
1/ Run engine to normal operating temp.
2/ Switch off engine.
3/ Replace ISC.
4/ Re-start engine.
5/ Remove dummy plug in the end of the Brown connector & ground the single wire. This will set the ISC to 'set position'
6/ Adjust base idle screw (not the screw with the locknut)to acheive base idle of 750+/-50 rpm.
7/ Remove ground to Brown connector & allow engine to idle for a couple min's.

Job done?


So here are a couple of my engine bay

I think the connector which needs to be grounded is the brown one just to the left of my screen wash pipe


Here is a closer shot.

Can anyone confirm that this IS the correct connector?

SteveN

Answers to your questions...

You may not need to set the base idle after replacing the IAC. I didn't. I *did* end up doing the steps on page 9 of the Intro and Master Troubleshooting section of the FSM:

2) After completion of the work steps (when the battery's negative[-] terminal is connected), warm up the engine and allow it to idle for approximately five minutes (lights off, transmission in neutral or park, steering wheel centered), then check for satisfactory idle. For 3.0L engine models, if the engine rpm is high, switch OFF the ignition switch, and then, after switching it ON again, let the engine idle for 2 or 3 minutes. This will cause the engine rpm to decrease about 100 rpm, so repeat this procedure until the prescribed idling speed is reached.

If you need to set the base idle speed, here's the procedure from page 14-63 of the FSM.

Same preconditions as noted above...

1) Connect tachometer
2) Disconnect the female connector for waterproof from the connector for ignition timing adjustment.
3) Using a lead wire with alligator clips, ground the terminal for adjustment of the ignition timing.
4) Using a lead wire with alligator clips ground the No. 10 terminal of the self-diagnosis connector (behind the glove box)
5) Start the engine and run at idle.
6) if idle speed is not 700+-50 rpm, use the speed adjustment screw to adjust the rpm accordingly.
7) Shut off the engine, disconnect grounds, plug up the connector again. Start engine, let it idle for 5 minutes, verify that idle is OK.

NOTE that the order of this is slightly different from what you posted, plus you need to ground the No. 10 terminal of the self-diagnosis connector. If you're not sure which one it is, go to MontyMcV's website, download the appropriate FSM, and look in the MPI section for these same instructions plus pictures! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Lastly, I believe the connector you show is in fact the ignition timing adjustment connector.

Let us know how it goes!

Eric W.

Just a quick up-date
Installed the new ISC sunday, idle was a little high, followed Erics switch off/on restart and now idle is steady at 750-800rpm in park.

The new ISC is a genuine Mitsu, well it has the 3 diamonds moulded into the case along with the relevant part no.

Coil values are all ~40ohm.

This is the second time around for this, first time was about 6 years back & I got a recon unit for more $'s than this new one <img src="/forums/images/graemlins/confused.gif" alt="" /> still both were/are significantly cheaper than Mitsu UK which runs @ approx $1000 (inc tax)

Thanks again to all who offered help <img src="/forums/images/graemlins/cheers.gif" alt="" />

SteveN

<img src="/forums/images/graemlins/zombie.gif" alt="" /> <img src="/forums/images/graemlins/zombie.gif" alt="" /> <img src="/forums/images/graemlins/zombie.gif" alt="" />

<img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

$1000??? <img src="/forums/images/graemlins/scared.gif" alt="" /> That's some hefty markup! Glad you were able to get the Mitsu part elsewhere. Here's to many Km's of trouble-free idling <img src="/forums/images/graemlins/smile.gif" alt="" />

Eric W.