Low Idle

[Silver MK3]

I have a question about my 87 non-turbo supra (71k original miles), and was hoping someone could help me out. Sometimes when I start my car, it idles real low (around 400) until I give it gas, and then it usually goes to a normal idle. For example, today, when I went to the store it started fine the first time and again when I left the store. After I stoped at another place the car it idled so low that it cut off, I tried to start the car again and gave it some gas but it cut off again.:: angry :: The third time I tried, it idled low but went to a normal idle after I gave it some gas.

The strange thing is that it's hit and miss. I would guess two out of three times it has a low idle at start-up, but usually after a few seconds it goes back to a normal idle. Once it is running it seems to hold the correct idle. I'm wondering if it has something to do with the choke, but I don't really know where to start.

Any thoughts or insights are greatly appreciated.

 

[A. Jay]

Try searching for "hot start" or "warm start." Hope that helps.

- from my Archos 5 IT

 

[supraseoul1]

i have the same problem. it could be your o2 sensor on mine the wire was ripped and caused low idle, or the tps or cps one of those

 

[Silver MK3]

Thanks for all of the input guys. I checked the ISCV, water temperature sensor, cold start injector, cold start injector time switch, and the AFM. Everything cheked out fine, but I was still having the low idle issue when restarting it after 10-15 minutes of cooling down from operating temperature. So... I burned up some of the 89 octane:evil2: that was left in it and filled it up with 92 octane. So far so good, it seems to be running fine, and I haven't had any low idle issues for a few days now. Hopefully it was just the lower octane fuel:x:. I also read in the front of my owners manual that even in 1987 they were warning of potential performance issues with "gasahol", which is essentially the same as the ethanol mix that most gas stations sell now. If this doesn't clear it up I'll update this post.
Thanks Again,
Gavyn

 

[mkIIIman089]

If the fuel was the problem, it wasn't from octane. It'll run on 87 just fine in stock form.

 

[Silver MK3]

Well, the problem is back and I don't know what it could be.:3d_frown: When I got back from driving the Supra around, I turned it off for 30 minutes then started it up and took a video of it doing the low idle thing.

Here's the video: (The A/C was on and it was about 96 degrees outside.) You have to click on it to play it.

Sometimes when it does this it dies, or it will recover and go back to a normal idle like it did in this video. If anyone else has experienced this problem, or knows what the problem is or could be I would greatly appreciate your input.:1zhelp:

 

[Wildfire007]

I have an 88 Supra Turbo and have the same exact problem. I'm at least happy to see it is not an uncommon one with that model car.

 

[AJ'S 88NA]

Have you adjusted your TPS and timing? TPS is a wear item and sometimes needs adjusted.

 

[mkIIIman089]

Step 1 is always to check codes, which would show if the TPS was out of spec. So start there and report back.

 

[Silver MK3]

Hey guys thanks for the responses. I checked for codes, and I don't have any. I also checked the TPS and timming which were both in spec. I don't have a clue what the problem is.

I have an 88 Supra Turbo and have the same exact problem. I'm at least happy to see it is not an uncommon one with that model car.

Maybe, its just a problem with silver MK3's in Alabama.:icon_bigg

 

[Wildfire007]

Hahaha wow man I didn't notice you lived in Madison. Sadly I guarantee yours looks way better. I'm still trying to fix mine up. The console stuff was ripped out, glove box ripped out, and outside bump guards missing all down one side. But eventually it's gonna look beautiful.

 

[Silver MK3]

Well the problem is still here. I noticed that my efi relay in the fuse box by the battery was getting very hot, and was discolored so I went to the dealer to order a new one. It should be here either Saturday or Tuesday. I asked the parts manager if this could be causing the hot start problem and he said that it probably is, so I am hoping that it fixes it.

I also checked my codes again because I noticed that my check engine light would come on when it wouldn't start correctly, and it showed that I have code 14. I pulled my efi relay to clear the codes and checked them again the next day and I had code 14 again. On the tsrm website it says that code 14 is No "IGF" signal to ECU "A" 3 times in succession. It says that the trouble area is the igniter, ignition coil, ignition coil circuit, or the ECU. If someone can help me out with this code, that would be great.

 

[Turbo Habanero]

Notice that it happens on warm starts after you have been driving... Most of the time it is a Case of (A term called) Heat Soak. Do some research on it you might find this is your problem

 

[Silver MK3]

Notice that it happens on warm starts after you have been driving... Most of the time it is a Case of (A term called) Heat Soak. Do some research on it you might find this is your problem

I have been researching this, and it sounds like it may be the problem. Is there any way to tell if it is the problem, or any way to prevent heat soak?

 

[Turbo Habanero]

Exhaust wrap. Heat shields. Even try exhaust wrap on the Intercooler pipe. Getting air into the engine bay is good aftermarket hoods with vents can help

Improving intake termps helps out.

Either way if this is your problem its not such a big deal it wont hurt your motor as far as i know

 

[Silver MK3]

Exhaust wrap. Heat shields. Even try exhaust wrap on the Intercooler pipe. Getting air into the engine bay is good aftermarket hoods with vents can help

Improving intake termps helps out.

Either way if this is your problem its not such a big deal it wont hurt your motor as far as i know

I actually dont have a turbo motor, so I would think that the whole engine bay stays a little bit cooler. I don't think it is that big of a problem either, but it can get annoying when it takes several attempts to start the car. It might just be that it has been an above average summer this year for the temperatures.

 

[Turbo Habanero]

Shouldn't be keeping the car from starting. I live in southern Arizona and my car starts everytime but somtimes it will get heat soaked but still starts

 

[Silver MK3]

The car will start, but it won't hold an idle. The rpms will jump around really low, and it will usually stall unless I rev the engine a couple of times, then it will begin to idle. When I said that it takes several attempts to start the car I meant that the car won't hold an idle and will stall, not that I have to crank the key several times for it to start.

 

[Turbo Habanero]

I understand i would start with going over all the vacuum lines in the car and make sure they are fasten and tight

Air filter change and plugs and wires