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Cadillac Repair/1981 cadillac eldorado 6 liter

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Question
I have a 1981 Biarritz with that engine with only 107,000 miles. I believe it only runs in the 8 cylinder mode. Could you tell me where to locate the "wire" that disconnects the 6&4 cylinder modes?

This all started when I had to have the car smoged. It repeatedly failed. I ended up replacing the catalytic convertor, put  in a new EGR, O-2 sensors, PCV valve, etc.

I have an accleration problem. In the morning when I first start it, if I acclerate too quickly it "pops" like a mini-backfire that sounds like it comes from the throttle body. It has been tuned-up recently with new plugs and wires and I think distributor rotor &condenser (but I'm not sure)were replaced. Is the timing automatically set by the computer? Can it be checked the old way and adjusted? I believe they did checked the timing at the shop, but they are telling me it has to do with the transmission as well.

My transmission, for at least two years has not functioned correctly, but prior to recently, the engine had adequate pick-up, did not hesitate and ran pretty smoothly.
It ran well despite the fact that it shifts from 1st to 3rd gear completely bypassing 2nd. I have tolerated it because of expense, and because it is drivable under normal circumstances. It shifts from 1st to third at 20mph under typical accleration. It will not back down to 2nd while in third ((no kickdown unless I am in the 35 to 40mph range where it will go to first) There is no engine "breaking" effect when I am acclerating to 20mph and back off the pedal as there would be if it were in 1st manually.

Last, when I start it in the morning,( where you hear the fuel pump working just prior to cranking) the idle screw will often "pulsate" (where you can hear the little motor turning) and make the acclerator pedal move back and forth. Also when I coast to a stop, occasionally the pedal will go down, which is pretty scary. I was wondering if there was ever a recall for that on this model or any other recall you may know about.

Thanks,

Christopher,  

Answer
Hi Christopher,

My expertise does not deal in your questions except for one. I am going off my old feable memory because I owned one of these cars.
If I remember right, on the driver's side of the engine, there was a single wire near the valve cover that was either brown or green with a black connector. This wire was not harnessed and disconnecting let the engine run on all 8 cylinder.
There were so many problems associated with the 4-6-8, but it was a great engine running on 8.
Sorry about being so vague, but I am speaking from 18 years ago.

Hope it helps and if you get it unplugged it may fix a number of your problems hopefully.


Rob

Cadillac Repair

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Rob Painter

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Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?

Experience

Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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