High Idle/Running rich (black smoke)[700/1984]

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High Idle/Running rich (black smoke)[700/1984] posted by Keith LaCrosse on
Sunday, 18 October 1998, at 9:23 a.m.

I have a 84 760 with a B23Ft, AW71 w/OD that is not running quite right.
I just replaced both the engine and left fender (driver) side wiring harnesses (volvo). I have also replaced all vacum/intake/wastegate hoses.
Both temp senders in the head replaced. Throttle body has been cleaned and set up per the Volvo manual. All injector seals replaced. Idle control valve cleaned. New gaskets as required. AMM not touched but look "OK". Did check resistance and got a reading of 4.1 ohms at 70 degrees F, engine cold. All connections and hose clamps have been checked and rechecked for tightness/fit.

Now the problem: After all the work was done and I started it and the idle went to 1800 rpm or so and would not come down. Grounded the idle control wire per the book and used thumb screw on throttle body to bring the idle to 1000. In doing this the thumb screw bottomed in the bore. Is that normal? It seems to idle OK but it is still about 200 rpm to high.

Problem 2. It drives OK till you try and "floor" it. The engine seems to bog and miss and not want to pick up power/speed (does show boost). I can also see black smoke from the tail pipe. Could it be the O2 sensor? I am open to any suggestions. Thanks

--
Keith 86 740 205k, 84 760 167k

Re: High Idle/Running rich (black smoke)[700/1984] posted by Alex Hughes on
Friday, 23 October 1998, at 12:40 a.m.

Very similar situation in my '86 745T drove me nearly crazy for about 2 months. It was a leaking fuel injector. private e-mail if you want to know more.

Alex Hughes --
Alex

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