Resolved No Start, coolent temp sensor, through it was isc

[SnowmanFD]

(This happened about 3 weeks ago) i was out driving with some friends and went to the car wash, when i went to start the car again it would start then die. a friend of mine who used to drive an rx7 got in and manually idled it then it idled fine and i went home. the next day it would crank but not turn over so i did what you would do on most cars and check for air, fuel, spark, compression, ect...

i thought i had concluded it to be fuel because the car would start with starting fluid but then die so the first thing i check was if i was getting fuel to the rail. I did this by removing the line from the rail and trying to start the car. It filled up the cup so i knew my fuel pump was working fine

Then i had my friend come over to try and help my figure it out and we decided to start the car again with starting fluid my friend then manually idled the car ran fine (besides the cel) so we now think its the iacv. The new one arrived this morning and ive been trying to install it all day and i think i either bought the wrong part, im trying to put it in the wrong spot or something. So where i think the iacv is it seems to be just a flat metal plate and the harness is on the outside i took all of that off and just tried to install it and it doesnt even fit this is the part i ordered https://www.stockwiseauto.com/stand...control-valve?Year=1990&Make=Eagle&Model=Talo

i honestly dont know at this point. And just want my car runing again, any help is much appreciated.

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[steve]

Was the ISC always unplugged or did you do that?

This is what a 90 ISC looks like.

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And installed on the Throttle Body

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[SnowmanFD]

Was the ISC always unplugged or did you do that?

This is what a 90 ISC looks like.

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And installed on the Throttle Body

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I unplugged it to try and remove what i think is the isc

 

[Mech Addict]

Keep in mind that the 1990 throttle body is a little different than 91-94 (as with too many things…), so perhaps that is the issue here. I can’t tell which one Steve posted photos of. I l have my original 90 t.b. In a box, and a nice new old stock 90 t.b. on my car (magical ebay find a few years ago, absolutely brand new in mfr box). If you need photos of anything of how it’s supposed to look, let me know.

 

[pauleyman]

I followed your link and that's the wrong part.

ISC would probably not cause a no start. Do you have access to a logger?
You obviously have air fuel and spark as once it's running you can keep it running. Did you knock off any connectors while washing? I assume you meant you washed engine bay?

You also stated you have a CEL. So what is it? I assume you did not have one before. ISC does not flag a CEL

 

[AWD-Tony]

Why not test the old isc to see if it's bad? I'd look into the cas next if isc passes. Sounds like you have no injector pulse.

 

[steve]

I don't think we ever saw the inside of that 94 ECU you're running.
Did you wire up the 91+ PTU to fix your tach issues?

Do you know how to measure the coil resistance of the ISC?

 

[SnowmanFD]

I followed your link and that's the wrong part.

ISC would probably not cause a no start. Do you have access to a logger?
You obviously have air fuel and spark as once it's running you can keep it running. Did you knock off any connectors while washing? I assume you meant you washed engine bay?

You also stated you have a CEL. So what is it? I assume you did not have one before. ISC does not flag a

I only washed the exterior not the engine bay, i did some reading and my thought was because the car was at a certain temp and then i washed it with cold water the car kinda freaked out and struggled to idle.
back when it was runing my cel light would come on after "long" (50 miles) drives and sometimes when starting it but when i try to read it, it would already be gone after i turn the car off im trying to use this method http://web.archive.org/web/20100815101158/http://dmtalon.v8eaters.com/ISC.html and when i go to put it in the on position the cel is gone. I do have a pretty big exhaust leak so thats my best guess but its after the o2 sensor so idk

I don't think we ever saw the inside of that 94 ECU you're running.
Did you wire up the 91+ PTU to fix your tach issues?

Do you know how to measure the coil resistance of the ISC?

I have the new pt just havent put it in yet, this is the best photo i have because i was just trying to see if it was eprom or not, i can get more if needed itd just be a pain to pull the ecu again

If your referring to this http://web.archive.org/web/20100815101158/http://dmtalon.v8eaters.com/ISC.html
Then yes i did test it and it seemed to work fine

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[pauleyman]

I only washed the exterior not the engine bay, i did some reading and my thought was because the car was at a certain temp and then i washed it with cold water the car kinda freaked out and struggled to idle.

back when it was runing my cel light would come on after "long" (50 miles) drives and sometimes when starting it but when i try to read it, it would already be gone after i turn the car off im trying to use this method http://web.archive.org/web/20100815101158/http://dmtalon.v8eaters.com/ISC.html and when i go to put it in the on position the cel is gone. I do have a pretty big exhaust leak so thats my best guess but its after the o2 sensor so idk

I only washed the exterior not the engine bay, i did some reading and my thought was because the car was at a certain temp and then i washed it with cold water the car kinda freaked out and struggled to idle.
back when it was runing my cel light would come on after "long" (50 miles) drives and sometimes when starting it but when i try to read it, it would already be gone after i turn the car off im trying to use this method http://web.archive.org/web/20100815101158/http://dmtalon.v8eaters.com/ISC.html and when i go to put it in the on position the cel is gone. I do have a pretty big exhaust leak so thats my best guess but its after the o2 sensor so idk

No. Washing exterior will not affect anything.
Check the CEL anyway even if there is no light.
The link you posted doesn't completely apply to you. 91 up cars use a different ISC motor. The process is the same but the actual part and it's location are different. Again ISC will not flag a CEL. It isn't a sensor. It's a motor. It still shouldn't cause a no start at all. Motor should at least try and start and potentially run poorly but you should be able to keep the car running applying throttle. Since this is all of a sudden there are things that can fail and cause issues. Datalogger would point them out quickly but in the absense of this some quick checks would be coolant temp sensor.
If the car starts consistently with starting fluid then remains running I'd say you have a fuel problem. Question is why? Is it amount delivered because of ECU or bad inputs to ECU from other sensors (coolant temp, TPS etc etc. ).
The car wash probably had no bearing, was just coincidental.
Exhaust leak downstream is not a problem as you don't have a second o2 in a 90 car. Even if it were before the o2 sensor when the car is cold the ECU isn't looking at O2 yet so it wouldn't affect a cold startup.

Is there anything that happened immediately before the car wash? Were you on the car hard? Does it try and catch at all or just dead cranking? You can pull a spark plug after a few cranks and smell it, see if there is fuel in the cylinder.

 

[SnowmanFD]

So what is the proper way to check a 90 cel?

Now that i think about it more i wasnt being hard on the car at all on the way there but on the way back i was pushing it a bit, nothing crazy but i did do a pull or two

The day it wouldn't start there where a few times where i would say it got close to starting but still wouldn't

I could try and pull a plug later today. Do you think it would just be better to try this?
"Un-bolt the fuel rail from the head, leaving the injectors in the rail and plugged in, after you remove the rail. Set the injectors on the head, facing the front of the car, once again placing them toward a bucket so it can catch the fuel as it sprays out. Have someone crank the car and watch the injectors, ensure ALL of them have a nice spray pattern and pulse as the engines cranking. Wearing eye protection while doing this check isn't a bad idea either, there is a chance you get sprayed with fuel."
Quote from: https://www.dsmtuners.com/threads/how-to-diagnose-a-no-start.217951/

 

[pauleyman]

I'm confused. You haven't posted anything on checking a CEL. You posted how to check an ISC.
If you want to check codes try this.

1G - 1g Code Reader - CEL CODE READER

This is a How-To on figuring out your Check engine light (CEL) for 1g.Tools: Volt Meter or LEDConnection: Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. You must be registered to see element.After you got that done, turn your key to the ON...

www.dsmtuners.com

The other link on no start is a good read. Since you are able to start it and keep it running I would start with the coolant temp sensor and not the fuel rail.

 

[steve]

I could try and pull a plug later today. Do you think it would just be better to try this?
"Un-bolt the fuel rail from the head, leaving the injectors in the rail and plugged in, after you remove the rail. Set the injectors on the head, facing the front of the car, once again placing them toward a bucket so it can catch the fuel as it sprays out. Have someone crank the car and watch the injectors, ensure ALL of them have a nice spray pattern and pulse as the engines cranking. Wearing eye protection while doing this check isn't a bad idea either, there is a chance you get sprayed with fuel."
Quote from: https://www.dsmtuners.com/threads/how-to-diagnose-a-no-start.217951/

Not to just verify you have fuel. That's a lot to do and disturbs things like the injector insulators which would likely need to be replaced because they are hard as a rock by now. It also runs the risk of pushing one of more injectors out of the rail and sending it across the room.

You should check your sparks plugs but the simple way to answer the question of if you have fuel is, does the car continue to run until you turn it off, while you are doing whatever you need to do to get it started? If it does then the pump is running.

You want to pull the spark plugs to see if they are fuel or oil fouled. Seeing fuel fouled plugs can be difficult so it's sometimes easier to put a fresh set in and see if it starts. If that helps I'd check the engine coolant temp connector. I see that Paul beat me to it...

 

[SnowmanFD]

I'm confused. You haven't posted anything on checking a CEL. You posted how to check an ISC.
If you want to check codes try this.

1G - 1g Code Reader - CEL CODE READER

This is a How-To on figuring out your Check engine light (CEL) for 1g.Tools: Volt Meter or LEDConnection: Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. You must be registered to see element.After you got that done, turn your key to the ON...

www.dsmtuners.com

The other link on no start is a good read. Since you are able to start it and keep it running I would start with the coolant temp sensor and not the fuel rail.

So when the check engine light comes on i got my volt meter, connect the prongs under the drivers dash then turn the key to the on position. When i turn it to the on position the cel is gone.
Am i doing something wrong?

Not to just verify you have fuel. That's a lot to do and disturbs things like the injector insulators which would likely need to be replaced because they are hard as a rock by now. It also runs the risk of pushing one of more injectors out of the rail and sending it across the room.

You should check your sparks plugs but the simple way to answer the question of if you have fuel is, does the car continue to run until you turn it off, while you are doing whatever you need to do to get it started? If it does then the pump is running.

You want to pull the spark plugs to see if they are fuel or oil fouled. Seeing fuel fouled plugs can be difficult so it's sometimes easier to put a fresh set in and see if it starts. If that helps I'd check the engine coolant temp connector. I see that Paul beat me to it...

when i start the car with starting fluid.

if i dont touch anything the car dies but if i give it some gas it will then hold the idle and run fine

Steve does this sound like the correct process?
-try to start it
-When it doesn't start pull a plug and see if i smell gas, see gas, if it's oil fouled, or wouldn't be working in any way,
-replace the plugs not matter what
-see if it starts

Also this is the part i removed last night thinking its the isc just for my own knowledge what is it?

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[pauleyman]

I think you've got a fuel delivery problem. Check the coolant sensor. You obviously have fuel. Seems like you don't have the correct amount. Eliminate the easy stuff first.

Also this is the part i removed last night thinking its the isc just for my own knowledge what is it?

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no that is not the isc. Post #2 shows the isc.

 

[SnowmanFD]

I think you've got a fuel delivery problem. Check the coolant sensor. You obviously have fuel. Seems like you don't have the correct amount. Eliminate the easy stuff first.

What about the coolent sensor?
Just install a new one or whats the deal

And im assuming its the one that tells the ecu not the one for the dash i think steve had mentioned something about there being 2

Also just wanted to say thanks so much for helping

 

[pauleyman]

What about the coolent sensor?
Just install a new one or whats the deal

And im assuming its the one that tells the ecu not the one for the dash i think steve had mentioned something about there being 2

Also just wanted to say thanks so much for helping

Read the no start tutorial. It has testing procedures for the coolant sensor. And yes the one for ECU not for the gauge.

 

[AWD-Tony]

Also this is the part i removed last night thinking its the isc just for my own knowledge what is it?

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That’s the fiav cover.

 

[steve]

if i dont touch anything the car dies but if i give it some gas it will then hold the idle and run fine

That proves that your fuel pump is running when it should and the injectors work.

The car dieing is likely an issue with your ISC and possible your BISS being all the way turned in.

BTW, your ECU has original capacitors. You should have them changed when you have the EPROM socketed. I highly recommend using ECMTuning for both. They won't F up your ECU in the process.

 

[SnowmanFD]

That proves that your fuel pump is running when it should and the injectors work.

The car dieing is likely an issue with your ISC and possible your BISS being all the way turned in.

BTW, your ECU has original capacitors. You should have them changed when you have the EPROM socketed. I highly recommend using ECMTuning for both. They won't F up your ECU in the process.

If thats the case, how do i test the biss? I know where it is but how should i ajust it, if its not the biss. First off where is the isc on a 90 tb and where can i buy one

 

[pauleyman]

If thats the case, how do i test the biss? I know where it is but how should i ajust it, if its not the biss. First off where is the isc on a 90 tb and where can i buy one

Post 2 shows isc clearly. I thought you said you tested it already.

 

[SnowmanFD]

If this is the isc (photo below), then yes i tested it and it works fine i used this website
http://dmtalon.v8eaters.com/ISC.html

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[19Eclipse90]

Yes, that is the plug for the ISC. I'll make Steve's pictures a little more detailed. The electrical connector on the left side of throttle body is the factory location for the connector; the second picture simply shows it is actually wired directly into the ISC.

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[pauleyman]

If that's the case I stand by my original statement. I doubt youbhave an isc or biss problem if car was running just fine then suddenly wasn't. Test the coolant sensor.

 

[SnowmanFD]

If that's the case I stand by my original statement. I doubt youbhave an isc or biss problem if car was running just fine then suddenly wasn't. Test the coolant sensor.

So i just tested the coolent sensor and im geting around 1800.

I just went and bout a new one ill try and install it now

 

[19Eclipse90]

Do note that at least for an initial trial, you don't actually have to remove the old and install the new sensor. Unplug the old and connect the new to the harness. The sensor will be reading approximately the same temperature whether it is installed or not while the engine is cool. Again, this is just a way to verify without doing a whole lot of extra leg work.

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