I own a 78 coupe deville and it rumbles and shakes when stopped or in park. Any suggestions?????

 

simply pull out the fuse and see if its running better. They are like 50 bucks. Hope this helps-Roy

 

Well, it looks like the brake problem has been solved. It was the brake booster. Replacing it wasn't easy...but the brakes no longer stick after driving a short distance.

Now, on the problem number 2. When first started, the car runs great but after about 2 minutes on the road, it becomes sluggish and surges when you maintain a steady speed around 45 mph. I also notice the smell of fuel after shutting the car off. I'm sure it's running rich, but it's fuel injected so what could be causing it?

 

Prom chip in the ECM.

 

Well, I swapped the ECM to a known good one and the car acts the same way. So, I don't suspect the PROM...that's what has me puzzled.

 

Three main things to look for that send signals to DFI and ECM for fuel mixture are MAP sensor Mat sensor and Oxygen sensor. Any codes pertaining to those??

 

I'd change the fuel filter. Cheap and easy plus it elimiates a potential problem area.

 

An update...when I first start the car, the engine lopes badly but will stay running. Then, once I get it on the road, it smooths out and seems to run OK. In town, the surging issue is evident but on the road at 45 mph or more, it's smooth and delivers 20+ mpg. I'm convinced it's a fuel issue causing the problem...too much a lower speeds. Some things I've done try to remedy the problem include:
- Plugs, cap, rotor, wires, air filter
- Cleaned the injectors
- New vacuum pump (old one had a cracked ear and the belt wouldn't stay tight)
- Replaced the ECM and PROM with known good units.
- Replaced the air pump check valve (old unit was cracked)

When I last drove it, the idle was very high when I left the house so I stopped and shut the car off. When I restarted it, it ran as though it was on one cylinder and sputtered badly. After nursing the car along for a few hundred yards, it began to run better and then smoothed out and ran fine. The idle was still very high, however. I got home, shut the car off and let it sit for a minute or two. Upon restarting, all was well and the idle was normal.

I have no idea what's going on now and your thoughts are welcome. On the upside, my brake issue chronicled in earlier posts has been resolved.

 

Another update - the more I drive the car, the better it now runs. Now, on to an electrical gremlin which is slowly draining the battery. I think it's in the level-ride compressor, when I connect the battery, the compressor click and energizes so I think it's the culprit. I disconnected it and we'll see what happens in a day or two when I try to start the car.

 

hi i have a 1981 eldorado biarritz hard top and i need somme body part (panel between the trunk and rear glass ) i want to know the name of the part and where we can found that part thank for answering