I'm back (again) (sort of). I've been spending all my otherwise free time trying to get this DeLorean roadworthy for the SEDOC trip. My problem now is that the car tends to idle at around 2000 RPM. Sometimes I can get it to go as low as 1600 RPM, and after revving it may hang closer to 3000 RPM. I have checked the obvious and not so obvious. The idle speed micro switch works fine. When I disconnect it or lightly touch the throttle, the idle increases by about 300 RPM. Reconnecting the switch or relaxing the throttle reduces the RPMs by about 300, but still maintains it at around 2000. I have tried swapping idle speed motors from another car which didn't help. I have tried using a different idle speed ECU with no difference either. I cleaned all the relevant electrical connections. I removed the rams horns and checked that the throttle plates close properly, are not obstructed or hanging up. I have checked the pop-off spring loaded thingys on the throttle plates, and they look fine. The brass air tube for the idle speed motor is tight in the intake manifold with a new o-ring. I further visually inspected it with a mirror & light. The tube for the cold start valve is secure and appears to not have any air leaks. The cold start valve doesn't dribble. The diode for the tach signal going into the idle speed ECU checks fine. The tach works fine but tends to rattle in sync with RPMs. It has been like this for thousands of miles anyway. What led up to this condition is I thought I might have a problem with my fuel system. I threw plenty of money at the problem and installed a rebuilt CPR & fuel distributor and replaced the injectors & seals. I had problems with drippy & suspect injectors, but cleared that up. After installing all this stuff I tried to adjust the air/fuel mixture with poor results. The cat kept glowing no matter what I tried. So I took the cat off and replaced it with an Ed Uding bypass pipe. I checked the fuel distributor to make sure it wasn't leaking fuel through the pin on the bottom. I checked the o-ring under it to make sure it was in place and not causing a vacuum leak. At this time I might have had the brass tube for the idle speed motor loose in the intake manifold, and that could have been a big part of my problem adjusting the air/fuel mixture & having the cat glow. Today I *think* I properly adjusted the air/fuel mixture using a dwell meter despite the fact that it idles around 2000 RPM. If I rev it higher it tends to run slightly richer. If I adjust it really lean then the idle decreases to a reasonable level, but it makes the engine run poorly and impossible to restart without pressing the air meter flap or adjusting the mixture richer. If I unplug the idle speed motor, it causes the engine to stall. If I unplug the idle speed ECU, this does some interesting stuff. Normally when I do this to any DeLorean, the car still runs fine but idles a bit too fast. On this car unplugging the ECU causes it to stall right away BUT with a different idle speed motor installed it doesn't stall. I haven't a clue why. Can anyone tell me the pin-out on the idle speed motor so I can mess with it? I feel like I must be overlooking something really obvious. After all, what can make a car idle so fast? Walt Yahoo! Groups Sponsor ADVERTISEMENT <http://rd.yahoo.com/M=259538.3887155.5125412.1261774/D=egroupweb/S=170512 6215:HM/A=1750876/R=0/SIG=11v1mrq3u/*http://hits.411web.com/cgi-bin/hit?pa ge=1762-1062629109228440> click here <http://us.adserver.yahoo.com/l?M=259538.3887155.5125412.1261774/D=egroupm ail/S=:HM/A=1750876/rand=145170910> To unsubscribe from this group, send an email to: DMCForum-unsubscribe@xxxxxxxxxxxxxxx Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> .
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