Idle Speed Control problems

4GTuner

Help Support 4GTuner:

Well I have new idle issue. Idle is low around 4-500 rpm. Id doesnt do the faster idle at startup either. I think its isc related. Pulled isc and tested coils- ok. Checked spindle turns fine. Plugged it in and it just chatters. It looks to be fully projected...
So I pulled it back apart and wuond the pintle back to retracted. Plugged it back in and after turning on and off a few times the only way it moves is out. It will not retract.

Unplugged isc and measure voltage at middle pins (2-4) with key on is battery voltage.
Next tried to read resistance to earth on 1, 3, 5, 6 with key on. No luck with that.
Next with voltmeter red on pin 2 and black on pin 1 and key on. It shows 12v intermittent (hard to explain). Then red on 2 and black on 3, reads similar. Then red on 4 and test 5, 6.
Anyways the green was different (5?)
Pull ecu and check continuity on green wire. Ok.

Looks like its the driver ic in ecu (I only changed one of mine last time and this is the other one) Just about to change it out. Will report back...
 
Yep. No telltales that the driver was shagged. Just compared old one and new one and the output on pin1 of the driver was open. Pin7 output was fine...
Anyway, swapped it out didnt have a holder so put it straight on the board.
All back together now and idles real nice.
So thats a coil and a driver ic today...NEXT! !
 
had annoying stall and bad idle problem with evo no ammount of pissing about with it would make a difference.....went to shelf in shed grabbed a couple of the Isc thinking Change out.

whacked the first one in and presto...all good.

just checked the coils per video and all have same resistance.....the old one is covered in soot or black shit of some sort. Going to disassemble and see is it is jammed
 
Anyone got a pic of where the ISC is located on a 4G93T? (or 4G63, I'm assuming they're in the same location)
I just bought a new ISC and gonna swap it over on the weekend.
 
That's what she said...well not really
:p

Thanks, I'll look into it on the weekend or tomorrow morning.
ETA on installation?
 
Under throttle body. Plug it in before you install it and flick key on and off to see if its working correctly. Moving in and out smoothly and not clicking/sputtering or spazzing out.

5 min install. I have a small ratchet the drives those 1/4 hex bits (and extensions).The phillips screws can be a bitch, and the ratchet helps. A screwdriver just chews them up. You could put in some socket screws if you are finiky.
If the ratchet wants to chew the screws too, your best to pull the tb off and try with a cordless drill holding the phillips bit. The click click of the torque limiter is a bit of a rattle gun and you can really lean on it for a good bite.
If its still stuck of stuffed by the last guy, you can chisel the screws around. Last resort is to drill the screw head off and use vice grips to remove leftovers.

can i have your old one? One 9f the coils should be ok, and i can solder it into my spare.
 
Lemsta2 said:
That's what she said...well not really
:p

Thanks, I'll look into it on the weekend or tomorrow morning.
ETA on installation?
Click to expand...
Its different with a woman...any hole is a goal.
Theres 3 to choose from!
 
I'm having this issue on cold start up.

https://www.youtube.com/watch?v=B8gRdGq9qmo&feature=youtu.be

I'm not pressing the gas at all, it just does this for 2-3 mins. Revs up to 3000rpm then drops quickly then revs back up to 3000rpm and drops again and again. After 2-3 mins when the engine warms up its stops and gradually drops idle back to 1000rpm.

Any ideas what could be the cause of this? I've replaced the ISC so don't think it can be that. Any help would be appreciated.
 
When I first got my car it had an issue like this and it ended up being the tps, the signal must have been fluctuating or something so the ecu was compensating by opening and closing the isc. Could be your issue.
 
Hook up some jumper wires (Alligator clips) to the TPS. The POS+ to the Number 1 terminal and the NEG - to the number 4.

The terminals are: 4, 2 and 1

There is a space for #3 but there is nothing there.

_II__________II___II__

_4___________2___ 1 _



Measuring the resistance, set meter to Ohms.

It should read 5K Ohms. This is the resistance in the closed throttle position.

Now, move the POS + jumper wire to the number 2 terminal. Leave NEG - on number 4.



With the throttle closed it should read .9K Ohms (Changed per Data logger). Pic shows 1.1K Ohms.

Open the throttle all the way open and the meter needle should move while opening and stop at 5K Ohms.

Loosen the two screws (Phillips screwdriver) and rotate it to set the closed resistance to .9K Ohms (Haynes say 1.1 Ohms but Datalogger rebukes that). The pin resistance will remain about the same (5K).
 
Cool, thanks. So if I follow these instructions and find a fault, does that mean my TPS is stuffed?
(Sorry for noob questions)
 
Hook up some jumper wires (Alligator clips) to the TPS. The POS+ to the Number 1 terminal and the NEG - to the number 4.
Measuring the resistance, set meter to Ohms.
It should read 5K Ohms. This is the resistance in the closed throttle position.
Mine reads 4.76K Ohms

Now, move the POS + jumper wire to the number 2 terminal. Leave NEG - on number 4
With the throttle closed it should read .9K Ohms
Mine reads 56.5 Ohms (this looks bad)

Open the throttle all the way open and the meter needle should move while opening and stop at 5K Ohms
Mine reads 4.81K Ohms

Does that mean my TPS is stuffed?
 

Similar threads

BMGTZ
EVO 7 GTA
Replies
2
Views
1K
BMGTZ
BMGTZ
Bodman456
Boden's RVR HSGR
2 3 4
Replies
79
Views
13K
jengi
J
M
4G93T running lean?
Replies
1
Views
742
aapje
A
3VOLUTIONIST
Cold start issues
2
Replies
24
Views
4K
3VOLUTIONIST
3VOLUTIONIST
T
Tuning Problem???
Replies
7
Views
817
evo-gsr
evo-gsr

Latest posts

Back
Top