74 2.0L, Running Very Rich, owner quite confused, need diagnostic help |
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74 2.0L, Running Very Rich, owner quite confused, need diagnostic help |
drumsticks2112 |
Sep 20 2009, 12:56 PM
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#1
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Newbie Group: Members Posts: 7 Joined: 29-October 08 From: New London Member No.: 9,704 Region Association: Upper MidWest |
Car fires without a problem, but idles quite rough, and runs very rich, so much so that when the it settles down to normal idles, it floods out. MPS was replaced with a used but tested one recently. When it was last running ( a year ago) it ran a little rich, but nothing like this.
As of now, the CHT is not connected. When it is connected, the RPMs jump up to 4000 and stay there. When the CHT is bypassed with direct grounding of the harness, the results are the same as with the sensor being disconnected. I have no reason to suspect the injectors, FPR, Decel Valve, or the MPS. Any and all advice is welcome. -Todd |
r_towle |
Oct 2 2009, 01:13 PM
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#2
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Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
There is no fuel pressure sensor...a fuel pressure regulator, yes.
The TPS is the throttle position switch. The static fuel is from the cold start valve that may be stuck open...I ended up there also...after fixing everything else. that is kicked off by the ambient air temp sensor (mounted under the plenum) Try routing around the cold start injector...unplug it electrically, remove the fuel from it (add a long line to route around it... I did that...it stopped running super rich. Rich |
CHAZT54 |
Oct 2 2009, 03:42 PM
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#3
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CHAZT54 Group: Members Posts: 19 Joined: 29-December 08 From: New London, Wisconsin Member No.: 9,878 Region Association: Upper MidWest |
There is no fuel pressure sensor...a fuel pressure regulator, yes. The TPS is the throttle position switch. The static fuel is from the cold start valve that may be stuck open...I ended up there also...after fixing everything else. that is kicked off by the ambient air temp sensor (mounted under the plenum) Try routing around the cold start injector...unplug it electrically, remove the fuel from it (add a long line to route around it... I did that...it stopped running super rich. Rich yes - the fuel pressure sensor was a mis-statement. I will check out the cold start valve as you suggested. Could the pressure reg. be set too high? I haven't touched it since I bought the car a year ago so I didn't suspect a problem there. THANKS RICH. |
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