Hello all.

I just bought an 83 T-brat. Looks real clean, runs great... kinda.

I took it in for its last emission check and it failed. They said it is idling too high around 1,200 rpm. It passed the actual emission level (barely). Moreover, the temperature gauge is not reading at all. It will sit at the very bottom but ocasionaly perk up a little then back down to nothing. Lastly, they said the rpm under constant gas will not stay steady. It will idle at 2,500 rpm then drop to 2,300 then back to 2,500. Ive only heard of this happening due to a bad water pump. Is that my problem?

The car drives great otherwise. Any suggestions will be greatly appreciated.

I'm not well versed in the ea81t setup, but you should be able to adjust the idle. First off check the tension on the throttle cable, if its too tight it will cause high idling. If this checks out, then look to the adjuster screw.

 

Pic from above manifold.

 

 

For the inconsistant rpm, read up on shaft play in distributors. You can search the board. It may be in the early stages of play, and getting a rebuilt one may be an option if it is.

Or it could be tranny related.

I'm not well versed in the ea81t setup, but you should be able to adjust the idle. First off check the tension on the throttle cable, if its too tight it will cause high idling. If this checks out, then look to the adjuster screw.

 

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Well, that's a good idea, but what's in you're picture is not the idle screw. The little screw in with the red mark in the picture SHOULD NOT BE ADJUSTED! It is the throttle shaft close set screw. It's not like a Carb where the main throttle bore opening is used for idle control. In the FI setup the, throttle is suppose to close completely, but just to where it touches the bore wall. Adjusting that screw can possibly lead to damge to the bore or a stuck throttle plate. The idle circuit is seperate from the main bore.

 

There is an actual idle adjust screw. It is in a recessed hole on the back portion of the throttle body. Flathead screw, turn it clockwise to drop the idle speed.

 

It would also be wise to test the idle switch portion of the TPS. Do you have a service manual?

Good catch. Now that I've went back and looked at the manifold. The idle screw is grease covered in the first pic.

Thanks for the advice.

if the inconsistent rpm is tranny related. How much time do i have until it goes out?

The tranny chirps a little at high rpm shifts, but feels strong.