iidieiv619

I just finished an engine swap on my 92 lude from a f22a1 to a f22b.

On some occasions the car's idle would be unstable, ranging from 1000-1500 rpm. I took off and cleaned the IACV and put it back on the throttle body. After that the car was idling fine until couple days later the idling situation resumed. This problem only occured when the car was at a stop. I am planning on getting a NEW IACV but that problem isnt of my concern yet i needed to introduce it to you before the actual subject of this thread.

THE PROBLEM:

On RARE occasions the cars idle would be bouncy/unstable/hesitant/skippy/ ONLY RIGHT after I have completed a shift (i.e., finishing a shift from 1st to 2nd, 2nd to 3rd.). As soon as the car was put into gear (i.e., 1st to 2nd) milliseconds after it would act as if the car wanted to stall. As when this happened I noticed my rpm would drop about 200 rpm below of what it was when I entered the gear (i.e., 3000 rpm quickly dropped to 2800 rpm, then quickly back up to 3000 and increasing).
I have also noticed that this has only happened on LONG drives ONLY!
I have an idea it is most likely that I need a NEW IACV but it could be something else.
I also have an idea that it could be the FITV, throttle body, vaccuum hoses or intake air filter???
I just want to know the problem before I start making any moves. Before I start buying parts/products that I dont need; things that dont make a difference.
Your reply will be a big help and I Thank You in advance.
Please no dumb/ignorant replies!

dakyone

an old 83 lude i used to have had a loose vacuum hose and it would stall almost every stop so thats an option. once it was fixed car was good again.

the iac valve is a good place to start chances are it will fix it. what kind of fuel does that engine require? I got hesitation all kinds when i first got my current 93 because the stupid dealer had low octane in there. Premium fuel might help you too.

iidieiv619

Engine requires Premium and thats what I put in it, the type of fuel was another of my concerns but i spoke to a close friend who is a mechanic and he said it could be the ignition coil or an O2 sensor???
Any thoughts?

dakyone

o2 sensor is a good place to start. If youve got the money, do a full tune up. most places replace the o2 sensor when you get a tune up anyhow. New plugs and new wires would be smart too. My mechanic told me that there are some spark plugs can cause hesitation in lower rpms.

SNsLude

There is a 3 or 4 page thread regarding the very symptoms you are describing. This is one of the most common problems on our ludes. Please search and check it out. It's most likely the fitv.

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-Steven