Rough Idle first mile, Any solutions? Options

[JawjaPorsche]

I am the original owner of a 1.7 with FI. I have replaced the vacuum hoses and had the injectors rebuilt by Witchhunter last year.

My question is this: My teener starts in two seconds or less. The idle at start is around 1600. When I get to my first stop sign after starting which is one mile, the teener either stalls or the tach is going up or down. When I go another mile and if the red light catches me, the teener is idling normally at 800. The car runs strong after two miles.

Is the AAR just not adjusting properly during the first five minutes?

I know this is a 40-year old car and it will not run like it came off the showroom floor but asking if there is a solution.

As usual, your response and help is greatly appreciated.

Terry

[JamesM]

If your idle is up and then comes down after a few minutes it sounds like the AAR is probably working correctly, but its easy enough to check. Just pull the hose going to the AAR at the air cleaner end and feel if it is sucking when cold, and not when hot.

I would probably check a couple other basics though. If the idle speed is hunting though I would check your head temp sensor for proper warm and cold values, sounds like you might be slightly lean. Also check the TPS to be sure its set properly to detect idle.


What year is your 1.7?

[JawjaPorsche]

If your idle is up and then comes down after a few minutes it sounds like the AAR is probably working correctly, but its easy enough to check. Just pull the hose going to the AAR at the air cleaner end and feel if it is sucking when cold, and not when hot.

I would probably check a couple other basics though. If the idle speed is hunting though I would check your head temp sensor for proper warm and cold values, sounds like you might be slightly lean. Also check the TPS to be sure its set properly to detect idle.


What year is your 1.7?

73, thanks for your help. Click on link below for pictures.

[JamesM]

If your idle is up and then comes down after a few minutes it sounds like the AAR is probably working correctly, but its easy enough to check. Just pull the hose going to the AAR at the air cleaner end and feel if it is sucking when cold, and not when hot.

I would probably check a couple other basics though. If the idle speed is hunting though I would check your head temp sensor for proper warm and cold values, sounds like you might be slightly lean. Also check the TPS to be sure its set properly to detect idle.


What year is your 1.7?

73, thanks for your help. Click on link below for pictures.

73's should have a mixture adjustment knob on the ECU you could play with to see if that helps.

Just re-read your original post, when you say the tach is going up and down did you mean the engine speed was hunting and the tach was reflecting that, or are you seeing large spikes/bounces on the tach with miss-fires?

[JawjaPorsche]

If your idle is up and then comes down after a few minutes it sounds like the AAR is probably working correctly, but its easy enough to check. Just pull the hose going to the AAR at the air cleaner end and feel if it is sucking when cold, and not when hot.

I would probably check a couple other basics though. If the idle speed is hunting though I would check your head temp sensor for proper warm and cold values, sounds like you might be slightly lean. Also check the TPS to be sure its set properly to detect idle.


What year is your 1.7?

73, thanks for your help. Click on link below for pictures.

73's should have a mixture adjustment knob on the ECU you could play with to see if that helps.

Just re-read your original post, when you say the tach is going up and down did you mean the engine speed was hunting and the tach was reflecting that, or are you seeing large spikes/bounces on the tach with miss-fires?

It was hunting. I am sorry I was not very clear. Thank you so much for your help.