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Registered
Join Date: Nov 2001
Location: Phoenix, AZ
Posts: 20
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Idle problem..rough at start
First of all: 87 944n/a 127k. "NEW"-idle stabilizer& allnew rubber hoses under intake manifold,fuel injectors,oxygen sens. spark plugs&wires,coil,throttle pos. switch, cleaned throttle body and had mixture set on a computerized system and if I missed anything it's probably new! I'm having that awful idle problem where after you take your foot off the accel. the idle tries to go way down and makes the engine vibrate real bad then the stabilizer kicks in and pulls it up. This also happens when driving like coming to a stop light. WHAT is making the idle drop and engine kinda shudder. When I had my mixture adjusted my mechanic said that the air flow meter ( the only thing I have'nt replaced) could only be adjusted to produce a reading of .4-.5 for the o2 level. It should be between .8-1.0. Eventually it will need replacing $300. I ordered a new fuel screen-maybe it is really clogged up and not letting enough fuel go by at idle???or does the fact that my AFM cannot get the right mixture setting have something to do with this. Runs great otherwise.
Please HELP if you've had this problem. |
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12-07-2001, 06:23 PM
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Registered
Join Date: Aug 2000
Location: Virginia Beach, VA
Posts: 1,791
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wow,
ok, here's your checklist: 1) check for a vacuum leak (that'll do it all the time) 2) check the auxiliary air regulator for leaks. also check the electrical connections to it. 3) clogged fuel injectors? (that'll do it too) 4) wrong fuel pressure at idle? (that happened to me before) 5) bad cold start valve? 6) bad air flow meter (or corroded electrical connections to it)? and there's one more thing that i KNOW causes this stupid problem but i can NOT remember it right now. i had a problem like this once and it turned out to be that a wire leading from the distributor was loose. not an ignition wire, but a "sensor" wire. funny how such a small thing caused such a big problem. while i was at it, i cleaned a ton of other corroded wires and the problem went away. good luck! obin
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"Resale value": the phrase most often uttered by people who are afraid to admit they can't afford their car. |
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12-07-2001, 07:40 PM
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Registered
Join Date: Nov 2001
Location: Phoenix, AZ
Posts: 20
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the only thing that I have not done is check the connectors and wires to all of the sensors--to see if there actually getting power or sending a signal. How do you use a voltmeter, I've seen them in stores but it looks complicated so I've never bought one. The problem still sounds like it's not getting enough air or fuel. I had the fuel filter changed about 1,500 miles ago, by the way I got the car after it had sat -in a garage, for 2 years. It's got great power when driving, I have K&N filter/throttle respnse cam.
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12-08-2001, 07:20 AM
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Registered
Join Date: Jun 2001
Location: Indianapolis, IN USA
Posts: 246
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When you installed the throttle response cam, did you readjust the throttle cable properly? It MUST allow the butterfly inside the throttle body to close COMPLETELY when you let off of the throttle or you'll never get the proper idle.
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Dennis Russell Indianapolis, IN USA 1987 944 n/a RLM #020131-3340 |
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12-08-2001, 10:54 AM
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Registered
Join Date: Jul 2000
Location: Sweden
Posts: 278
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Is the idle correctly adjusted? I have heard that if idle on a 85.5+ car is adjusted without disabling the idle stabilizer strange things can happened. I know this is kind of a shoot in the dark but it will not cost you anything to give it a try. The nice Porsche 944 Garage tells you how to do.
http://porsche-944-garage.tripod.com/shop-manual/fuel-08.htm Good luck! //Magnus
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944 N/A '83 |
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12-08-2001, 12:33 PM
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