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Mazdax605
Mazdax605 PowerDork
4/11/21 5:50 p.m.

Today two GRM peeps got to drive the Chariot. Imgon and Tony Sestito both really seemed to enjoy themselves. Imgon scared me a little bit. 

Mazdax605
Mazdax605 PowerDork
4/13/21 1:46 p.m.

Cool article written by our own Tony Sestito about the Chariot. 

 

Bang shift

John Welsh
John Welsh Mod Squad
4/13/21 2:17 p.m.

When you mentioned days ago that Tony saw The Chariot, I certainly hoped he would be writing about it. 

Mazdax605
Mazdax605 PowerDork
4/28/21 9:07 p.m.

Added some yellow Lamin-x to the fog lights on the Chariot. 

 

Mazdax605
Mazdax605 PowerDork
6/21/21 10:23 p.m.

Noticed the idle on the Chariot was a bit low last night and didn't seem to bump up with A/C on like it used to. Didn't seem to be anything else wrong. This evening I took it out to pick up my youngest son and it stalled on me when coming to a stop behind some traffic. Then while waiting for my son the idle was really extra low and stalled again. Drive home I kept the revs up and then turning around in the driveway it would stall every time it was anywhere near idle. Any ideas? 

Mr_Asa
Mr_Asa UberDork
6/21/21 11:20 p.m.

Idle air control circuit?  My truck does similar things when it is time for me to take the valve off and de-carbon and de-grease it.

Boost_Crazy
Boost_Crazy Dork
6/21/21 11:54 p.m.

There are a couple switches that are supposed to raise the idle under load. An easy one is on the power steering pump. It's meant to raise the idle when the pump is under load. It's a single wire that plugs onto a terminal on the side of the pump (towards the front) that can pop off. The main idle screw is on the throttle body, it may be under a black cap. If the o ring is old age dried out, the screw can vibrate, turn, and change the idle setting. Another switch is on the throttle body, a single wire on the adjustable stop. The AC  should also send a signal to the ECU to raise idle, but I forget where that input comes from. 
 

Also very common- the idle speed may just be set wrong in the first place. Often wrong on these engines since the correct procedure to set the idle is a little involved. A test connector needs to be grounded to center the idle control valve, then the idle is set. This gives the idle control a range of adjustment. Most people just turn the screw until it idles fine, and then it doesn't when something changes- like the weather or using the AC. 
 

Here is a pretty good rundown...

https://www.sixsigmatuning.com/dsm-idle-control

 

Mazdax605
Mazdax605 PowerDork
6/22/21 5:19 a.m.
Boost_Crazy said:

There are a couple switches that are supposed to raise the idle under load. An easy one is on the power steering pump. It's meant to raise the idle when the pump is under load. It's a single wire that plugs onto a terminal on the side of the pump (towards the front) that can pop off. The main idle screw is on the throttle body, it may be under a black cap. If the o ring is old age dried out, the screw can vibrate, turn, and change the idle setting. Another switch is on the throttle body, a single wire on the adjustable stop. The AC  should also send a signal to the ECU to raise idle, but I forget where that input comes from. 
 

Also very common- the idle speed may just be set wrong in the first place. Often wrong on these engines since the correct procedure to set the idle is a little involved. A test connector needs to be grounded to center the idle control valve, then the idle is set. This gives the idle control a range of adjustment. Most people just turn the screw until it idles fine, and then it doesn't when something changes- like the weather or using the AC. 
 

Here is a pretty good rundown...

https://www.sixsigmatuning.com/dsm-idle-control

 

Up until Sunday afternoon on my way to play hockey I had noticed that both the A/C compressor kicking on and the power steering pump under load would raise the idle, but it wasn't doing it that night. Then Monday evening it was even worse. Now it just won't idle at all. 

akylekoz
akylekoz SuperDork
6/22/21 5:22 a.m.

Just this week I was behind a Galant VR4 at a light it was super clean.  It has fender marker lights like an old Chrysler.  

Sorry no help on the idle.  Fox chassis mustangs and similar 5.0 cars had an idle issue that would go away after cycling the engine off and back on again.  It was more pronounced in the heat and in the presents of any vacuum leak.

Mndsm
Mndsm MegaDork
6/22/21 6:26 a.m.

I know on dsms, the idle control screw liked to back out. That may or may not apply here. 

Boost_Crazy
Boost_Crazy Dork
6/22/21 12:24 p.m.

In reply to Mazdax605 :

 

Up until Sunday afternoon on my way to play hockey I had noticed that both the A/C compressor kicking on and the power steering pump under load would raise the idle, but it wasn't doing it that night. Then Monday evening it was even worse. Now it just won't idle at all. 

 

That definitely sounds to me like the idle speed control motor is bumping into to the end of it's range of adjustment. It was likely maxed out before and now can't open up any farther to maintain the idle. The best fix is to reset the idle speed properly. The quickest and easiest fix that should get you close enough to not really notice a difference would be to give the large base idle set speed screw (might be under a black cap) a turn or so counter clockwise until the idle comes up. Shoot for the idle to be about 100 rpm high. It should relearn, move the idle control closer to center, and drop the idle back down where it should be over time. 
 

I just realized your throttle body is buried under an inter cooler. Here is a pic of the Evo 3 throttle body. The one on my Galant VR4 is similar, so yours should look pretty close. The set screw is on the bottom right, just above the throttle position sensor...

 

Mazdax605
Mazdax605 PowerDork
6/23/21 6:30 a.m.

Yesterday afternoon my 14 year old son and I pulled some of the piping from the AFM, inter-cooler, and throttle body off to gain access to the throttle body area. I was told by a few people to test the ISC. Of course just as we had torn it down the skies opened up, and we were drenched. Alarmingly I had the AFM sitting on the the windshield out of our way, and it got wet. I hope I didn't damage it. It was only in the rain briefly. We called it a day, and went out to run some errands. This morning before work I tested the resistance of the 4 coils of the ISC, and they were all around 28 ohms. I don't think this is my problem, but I had ordered a new one anyway. What is odd is that this car idled perfectly, and bumped up when A/C was used, or power steering pump had a load, and now it doesn't and won't even idle now. I'm leaning towards vacuum leak, but how does one find a leak when it won't even idle to try the carb cleaner trick?

Boost_Crazy
Boost_Crazy Dork
6/23/21 2:45 p.m.

I missed the part where now it won't idle at all, I thought it was just stalling under a/c and steering loads. A leak after the throttle body would raise the idle. A leak between the AFM and throttle body might keep it from idling if it's big enough. Quick test would be to unplug the AFM and start it. It should ignore the AFM signal and run, poorly. But it should idle. If it idles with the AFM unplugged, check for leaks in the piping (you can build a pressure tester if you have a compressor) or check the AFM itself- I don't think these go bad very often. 

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