caddy**2 Posted November 20, 2006 Report Share Posted November 20, 2006 I have a '94 Concours with 173,000 miles. Just recently it started giving me problems. It started out by making a groaning sound while sitting at a light. It would go away if I put it in neutral or park. I thought the transmission or torque converter was starting to go. Over the past couple of months the sound has became more frequent and now I intermittently get a stumble or hesitation when accelerating from a full stop. I thought for sure it is the transmission, but reading this website has given me some hope. I checked out the wires by spraying them with water in the dark. I thought I discovered the problem when I pulled the wires and found three of the coil posts badly rusted and corroded. I cleaned them up but the car ran just a bad. I have run through the Power Balance Test and thought I now had the problem solved. Cylinder 1 and 7 showed very little if no change in the RPM's. I switched the wires with ones from what I thought were good cylinders but the test still showed no change when the injectors was turned off. I switched the coils around but still no change. The funny thing is that the exhaust pipe attached to the manifold started smoking hot during the tests. I'm wondering if the catalytic converter is clogged and causing my problem. BTW, I'm also leaking a lot more oil then usual, could that be related to the inability of the engine to release it's exhaust. Anyway is there an easy way to check the catalytic converter to rule it out? Thanks, Tony Link to comment Share on other sites More sharing options...
Ranger Posted November 20, 2006 Report Share Posted November 20, 2006 Check the FPR to see if it is leaking. Then check the injectors to be sure that they are working and if so, not leaking. Link to comment Share on other sites More sharing options...
caddy**2 Posted November 20, 2006 Author Report Share Posted November 20, 2006 Is it safe to switch the injectors around? Like I said, it was cylinders 1 and 7 that showed almost no change during the Power Balance test. I'll pull the cover off tomorrow evening to check the fuel pressure regulator and if I don't something I'll switch the injectors with some other cylinder to rule them out. Also, is there a test to rule out the catalytic converter? Link to comment Share on other sites More sharing options...
BodybyFisher Posted November 20, 2006 Report Share Posted November 20, 2006 Here is the gage you are asking about: http://www.etoolcart.com/index.asp?PageAct...amp;ProdID=5014 Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
kigy311 Posted November 22, 2006 Report Share Posted November 22, 2006 I bet it is the catalytic converter that causes you the problem.I had the same problem with a Lincoln Continental and day by day it got worse until I just couldn't start it up no more.You could waste your money on a tester,take it to a muffler shop and let them test it or just separate the catalytic converter by loosing the four bolts and stick something between the two plates to keep a 1"-2" gap and test drive it.If is better,change the catalytic converter.By the way,are you loosing power under load,up the hills and/or poor performance when step on the throttle?If yes,change the SOB. Link to comment Share on other sites More sharing options...
caddy**2 Posted November 26, 2006 Author Report Share Posted November 26, 2006 I finally had the opportunity to work on the car today. I started by pulling the intake manifold cover and checking the FPR. The fuel rail appeared to be holding gas and not leaking. I switched the number 1 injector with the one in cylinder 2, closed her up and ran another power balance test. Still no change in the RPM's when cylinder 1 and 7 were shut off. I then proceeded to disconnect the catalytic converter to see if that made the engine run better. It didn't. I connected the cat back up and looked over the wires again. I checked what I thought was the number 1 wire wire with a test light, that's when I realized that I had the wires for cylinder 1 swiched with the wire for cylinder 7. I must have mixed them up when I cleaned the coils. I connected them correctly, ran another power balance test and now when cylinder 1 and 7 were shut off the RPM's dropped. I took the car out for a test drive and she runs great. I ran her up to 80 in second gear and she still had more pedal to go. My conclusion is that it must have been the three coil tips that were corroded that was causing my problem and not the catalytic converter. Thanks to all that responded with your suggestions. This is a great forum. Link to comment Share on other sites More sharing options...
mmarinov Posted November 27, 2006 Report Share Posted November 27, 2006 I then proceeded to disconnect the catalytic converter to see if that made the engine run better. It didn't. I connected the cat back up and looked over the wires again. I checked what I thought was the number 1 wire wire with a test light, that's when I realized that I had the wires for cylinder 1 swiched with the wire for cylinder 7. I must have mixed them up when I cleaned the coils. I connected them correctly, ran another power balance test and now when cylinder 1 and 7 were shut off the RPM's dropped. I took the car out for a test drive and she runs great. I ran her up to 80 in second gear and she still had more pedal to go. My conclusion is that it must have been the three coil tips that were corroded that was causing my problem and not the catalytic converter. Thanks to all that responded with your suggestions. This is a great forum. Good for you - I'm glad you got her fixed! Thank you for posting your resolution. MM <!--fonto:Arial--><span style="font-family:Arial"><!--/fonto-->2007 DTS Performance - 50K <!--fontc--></span><!--/fontc--> As a matter of fact, I <i>am</i> driving 70 MPH in a phone booth. Link to comment Share on other sites More sharing options...
mrchun Posted December 8, 2006 Report Share Posted December 8, 2006 I'm having the exact problem you described on a 1992 Seville. I just had my CAT (the previous owner had glass packs on it) replaced about a month ago and noticed the sound. When you say coils, do you mean on the distributor pack? How did you clean the coils? ...with sand paper? Link to comment Share on other sites More sharing options...
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