'89 740 gle

T.P. Crockmier · Jan 13th, 2009, 02:02

I own a 1989 740 GLE (16 Valve) and seeing as this car has spent 18 of its 20 years in a harsh Colorado environment, it has developed a host of minor, but annoying problems. The problem I am currently concerned with is a very high, and rough idle. The car will idle between 1200 and 1500 revs, and while idling it violently shakes. I replaced the air filter, and scrubbed the throttle body with a toothbrush and a bit of fuel injector cleaner. While perusing the internet, I continually read about a idle adjustment knob. None of the pictures or diagrams I found were for a 740, and when I was cleaning the throttle body, I searched high and low for this mystical knob, but have been unable to find it. I found plenty of adjustments for the throttle cable, but didn't adjust any of them, as I wasn't too clear on their function. So if anyone can point me in the right direction towards this knob, if there is one, that would be greatly apreciated. As would any other pointers as to how to help the car run better.

telmo · Jan 13th, 2009, 09:19

Have you cleaned/replaced the crankcase breather arrestor?
In normally aspirated engines are usual idle problems due to clogging.

Mike B · Jan 13th, 2009, 10:14

Im not sure about the 16v but on my 8v 740GLE , the idle adjuste is on the inlet side of the throttle body I will take a pick later when I go down to my car .
Regards
Mike B [Byrne]

Quote:

Originally Posted by T.P. Crockmier

I own a 1989 740 GLE (16 Valve) and seeing as this car has spent 18 of its 20 years in a harsh Colorado environment, it has developed a host of minor, but annoying problems. The problem I am currently concerned with is a very high, and rough idle. The car will idle between 1200 and 1500 revs, and while idling it violently shakes. I replaced the air filter, and scrubbed the throttle body with a toothbrush and a bit of fuel injector cleaner. While perusing the internet, I continually read about a idle adjustment knob. None of the pictures or diagrams I found were for a 740, and when I was cleaning the throttle body, I searched high and low for this mystical knob, but have been unable to find it. I found plenty of adjustments for the throttle cable, but didn't adjust any of them, as I wasn't too clear on their function. So if anyone can point me in the right direction towards this knob, if there is one, that would be greatly apreciated. As would any other pointers as to how to help the car run better.

RealEstate · Jan 13th, 2009, 14:46

Quote:

Originally Posted by T.P. Crockmier

.. is a very high, and rough idle. The car will idle between 1200 and 1500 revs, and while idling it violently shakes.

Hi,
Sounds as though it's more than just a simple adjustment. Have you checked all the 'stage 0' tuning aspects, beyond just the throttle body, eg dizzy etc? Suggest a look at:
http://www.brickboard.com/FAQ/700-90...ceSymptoms.htm
All the best,
Ben

T.P. Crockmier · Jan 13th, 2009, 17:23

Thank you all for your advice. I did manage to hunt down the idle adjustment, but it was already as low as it could go, which must mean that something else is causing the problem. I will check out the crankcase breather arrestor and the 'stage 0' tuning aspects.

Jan 13th, 2009, 02:02	#1
T.P. Crockmier New Member Last Online: Aug 25th, 2009 03:24 Join Date: Jan 2009 Location: Colorado Springs	'89 740 gle I own a 1989 740 GLE (16 Valve) and seeing as this car has spent 18 of its 20 years in a harsh Colorado environment, it has developed a host of minor, but annoying problems. The problem I am currently concerned with is a very high, and rough idle. The car will idle between 1200 and 1500 revs, and while idling it violently shakes. I replaced the air filter, and scrubbed the throttle body with a toothbrush and a bit of fuel injector cleaner. While perusing the internet, I continually read about a idle adjustment knob. None of the pictures or diagrams I found were for a 740, and when I was cleaning the throttle body, I searched high and low for this mystical knob, but have been unable to find it. I found plenty of adjustments for the throttle cable, but didn't adjust any of them, as I wasn't too clear on their function. So if anyone can point me in the right direction towards this knob, if there is one, that would be greatly apreciated. As would any other pointers as to how to help the car run better.

Jan 13th, 2009, 09:19	#2
telmo Member Last Online: Nov 18th, 2015 14:49 Join Date: Jun 2006 Location: Porto	Have you cleaned/replaced the crankcase breather arrestor? In normally aspirated engines are usual idle problems due to clogging.

Jan 13th, 2009, 17:23	#5
T.P. Crockmier New Member Last Online: Aug 25th, 2009 03:24 Join Date: Jan 2009 Location: Colorado Springs	Thank you all for your advice. I did manage to hunt down the idle adjustment, but it was already as low as it could go, which must mean that something else is causing the problem. I will check out the crankcase breather arrestor and the 'stage 0' tuning aspects.

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