Recently i did an engine swap on my 1986 GL-10 with a spare engine that i had laying around from the same year and make. Everything went as planned and i got it all put back together, the only thing is that after i start the car the engine idles between 1700-2100. When going through the manual it states that it should be idling at about 700 rpm. In the manual it states to turn the IAC, however I am not 100% sure where that is located since the pictures in the manual look different then the engine itself. Sadly I am not even sure if this is the problem or if it is something to do with the having a hose lose so it is not getting a proper vacuum, but i do know that it is good to know where things like this are located so i hope someone can help. thank you

Does it always idle that high, or only when it's cold? Normal cold idle is around those numbers.

after letting the engine warm up it idled at 1700.

Recessed screw in the throttle body, visible if looking straight down is the idle adjust.

 

Smaller recessed screw in tb is visible from the rear. This is the high idle adjust.

 

However, if you are using the same old manifold from the car, the issue is likely an air leak. Although, an air leak on a Maf based system will usually cause other running issues.

Gloyale has answered this question, Im not sure if the o.p. was looking for troubleshooting assistance or not. Sounds like he doesnt have much run time on it. Have u driven the car? I dont belive the adjustment screw can allow for that much adjustment. Warm up the car and unplug the harness to the IAC if the idle drops to spec then your problem is with the control part of the system. Faulty CTS the IAC itself etc. if the idle ramains high could still be the IAC, vac leak/s or something as simple as the throttle not returning.

If you havent set any codes yet, you will.

Gloyale has answered this question, Im not sure if the o.p. was looking for troubleshooting assistance or not. Sounds like he doesnt have much run time on it. Have u driven the car? I dont belive the adjustment screw can allow for that much adjustment. Warm up the car and unplug the harness to the IAC if the idle drops to spec then your problem is with the control part of the system. Faulty CTS the IAC itself etc. if the idle ramains high could still be the IAC, vac leak/s or something as simple as the throttle not returning.

If you havent set any codes yet, you will.

Well unplugging things in this case won'T show you much.

 

okay, let's clarify...there are 2 systems that affect idle on the ea82t.

 

There is an aav, (aux air valve) mounted to the top of the thermostats housing. This has a 2 wide connector, that powers a heating element. This element when heated closes the air passage. Kinduv like an electric choke setup on a carb. So unplugging that could actually increase idle. To test if this is the culprit system, simply clamp the hose from it to the throttle body after warmup......if idle drops, you have a faulty aav that is sticking open. I have simply plugged thse guys off on a few cars, since they are hard to find working ones.

 

There is also, a single wire, FICD solenoid....mounted on back of tb. Sticks straight up. This solenoid increases idle by about 300~500 rpm for air conditioner use. This one is probably not related. But this one if you unplug it would drop the idle if it had been active.

I missed the part where turbo was mentioned. I automatically thought SPFI. I guess being an 86 gl-10 means turbo.

Edited April 5, 201510 yr by ihscout54

I missed the part where turbo was mentioned. I automatically thought SPFI. I guess being an 86 gl-10 means turbo.

No. A non turbo 86 2wd gl10 would be spfi

 

An 85 non turbo gl10 would be carbed

thank you all for the speedy answers. what i did was to unscrew the IAS to get it to idle at a lower speed. although i am still unsure if that fixed the problem, but i suppose i will need to give it some road time before i know for sure. And yes its a 5 speed manual with turbo and 4 wheel drive toggle switch