ill go a head and give the ISC a test tomorrow. I replaced it about 3 weeks ago since my last one was all messed up. Ill see what will happen

my timing was way off so i went a head and pulled it back to 5 deg and i pulled my idle up a little bit. I also loosend my alt belt a little which seemed to help. The car dose not stall any more when the fans kick in. So far i still half to take it out on the free way to see. The idle still dose drop if i turn alot of the electrical stuff on in the car. so for some reason the idle drops when there is a load on the alternator which was reading 13.9v at idle. also I tested the ICS and it was reading between 30 and 32 oms at every coil. I dont have a 9V battery so i couldent test it that way.

It wouldn't hurt to replace the battery terminals. They are generally really cheap.

I drove the car again today and its still having the same problems. it will idle real low then when i turn any thing on that uses power the car dies. Any other ideas?

Does voltage stay at 13.9 when you turn on the electrical accessories?

How long ago did you replace your alternator?

Check the voltage across the terminals with nothing on and the car idling. Then turn on every accessory you can think of (before the car stalls out) and read the voltage, obviously it's going to drop as each load is applied but you should be okay above 10v.

If it IS your alternator, do NOT buy one from Adv. Auto , research that.

What was your logic behind loosing the alt belt? Make sure its tightened to the manual specs that they explain in there.

yes it dose stay at 13.9V the car only stalls when it warms up probobly when it goes into closed loop

exile said:

How long ago did you replace your alternator?

Check the voltage across the terminals with nothing on and the car idling. Then turn on every accessory you can think of (before the car stalls out) and read the voltage, obviously it's going to drop as each load is applied but you should be okay above 10v.

If it IS your alternator, do NOT buy one from Adv. Auto , research that.

What was your logic behind loosing the alt belt? Make sure its tightened to the manual specs that they explain in there.

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I dident replace the alt i replaced the ISC on the car. loosening the belt was wishful thinking . any way though its tight and good. I will try to load test the battery/alt today and see what happens. If it were the alt id just go to the junk yard cause im cheap like that if it wasent the alt or the battery what else is there? is there something that makes the ISC pull out as the load on the alt increases?

i just checked the Volts of the alt again. at idle its 13.9v when i turn on every thing i can it dropes to 12.4 i got 12.9 at one point but around 12.4 then when i turn the car off with every thing on i got 12.1v. what do you think. tomorrow im going to check the alt and see if the bearings are ok. what do you guys think so far.

TT_NS said:

ill go a head and give the ISC a test tomorrow. I replaced it about 3 weeks ago since my last one was all messed up. Ill see what will happen

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Depending on how your other ISC was messed up you could have blown the drivers on the ECU. Then it wouldn't matter if you had a perfect ISC because the ECU couldn't control it.

In the worst case when you pull your ECU and checkyou'll find the inside has burned parts. That makes it easy toi know it's bad but often ther are no signs of damage, the driver just does't work.

Steve

steve said:

Depending on how your other ISC was messed up you could have blown the drivers on the ECU. Then it wouldn't matter if you had a perfect ISC because the ECU couldn't control it.

In the worst case when you pull your ECU and checkyou'll find the inside has burned parts. That makes it easy toi know it's bad but often ther are no signs of damage, the driver just does't work.

Steve

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actualy i ended up replacing that the same time as i replaced the ISC because iw as having issues with my car not starting in the heat and i opend my ECU and it has a burn spot on it. so when i replaced it the car ran fine, for a while before it the car started doing this.

any one have any other ideas?

well i just had that problem. do you have anything hooked striaght to the battery, or a/c on while idle? my alternator fixed that problem when i got another one, but now im eating belts so i dont get it. try turning all your power accesories off and letting it idle

Same thing here..I drove the thing with a bad ISC for 2 months, and the ECU went bad on it (95 GST). I replaced the ALt at 1st...but that wasn't the problem.
My lights would like dim, and when the fans kicked in -the car was ideling at 350-400rpm, and stall. Also after the car warrmed up , and if I would get on the brakes (at night with the lights on) before a complete stop the car would stall.
I put a good ISC in, and adjusted the base idle with the BISS screw...after 2 weeks it started doing the same thing. I took it to the Mitsu dealer , and they said my ECU was bad, and was killing ISCs like crazy
Steve has a good point!! I would def chk the ISC, then the ECU!
best of luck to you!

ill go a head and check the ECU again but i changed the ISC motor before i changed my ECU. dose it matter that i got the ECU from a 91 talan non turbo and i got a 90 eclipse GS?

I would say 99% sure that it doesn't!
I know on Turbos the 92-94T ECUs needs some wires swapped if you want to put them in a 90 and 91.

TT_NS said:

ill go a head and check the ECU again but i changed the ISC motor before i changed my ECU. dose it matter that i got the ECU from a 91 talan non turbo and i got a 90 eclipse GS?

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It sure does just like it does on the turbo cars but since the NA cars don't use the MAF reset the one pin moves. It interesting that the pin in question happens to be the Idle Position Switch and without it correctly hooked up the ECU doesn't know to use the ISC or that the car is idling.

Steve

So are you saying that pin is moved on just the Turbo cars, or the N/A to. i found a vacume leak on the line to my PCV valve. i fixed it and it seemed to help for a little while then it started acting up a bit but not as much as before its kind of hard to tell i still got to take it on the road. Hop it worked

As far as I can tell between the 1990 and earlier ECU and the 91 and later ECU the signals on pins 6 and 14 swapped. Since the NA 2.0L cars use the same basic ECU board as the turbo cars but don't use one of the signals you only have to move the other one in the connector.

If I have this right on the '90 GS there should be a green wire on pin 6 (middle of the top row, bigest connector). It need to be released and moved to pin 14 (second from the left bottom row) which should be open if you put a '91+ ECU in the car.

You will still have the normal tech problems that come with this swap but the car should run normally.

Steve

what are those pins effect (what are they connected to)? also swapying the ecu wouldent happen to affect the tach to would it? because after i swaped that and the coil the tach would act all messed up on accel.

Please re-read my last two postings.

Steve

I just want to throw this out there it hasn't been touched on but just for clarity is you Eclispe Gs a Gs turbo car?

its just a reguler GS non turbo 2.0 im going to replace the ECU with a 90 as soon as i find one in a junk yard or something. thats my next plan. because im also haveing issues with the tach acting funny.