Jan Olsson Posted December 9, 2007 Report Share Posted December 9, 2007 No codes, misses on idle, seems like it goes away when raising the rpm. Checked the plugs and changed them, no. 1 plug was wet. Going to check if I have a leaking injector tomorow, if not I will check the compression. Any ideas? Janne Link to comment Share on other sites More sharing options...
MAC Posted December 9, 2007 Report Share Posted December 9, 2007 I take it that #1 plug was wet with oil? Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 9, 2007 Author Report Share Posted December 9, 2007 I take it that #1 plug was wet with oil? Nope, gasoline. Acts just like a igniton miss, an occaissonal miss on idle that has developed to an estimated 50% miss on that cylinder Link to comment Share on other sites More sharing options...
Ranger Posted December 9, 2007 Report Share Posted December 9, 2007 Injector would be my guess Jan. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 9, 2007 Author Report Share Posted December 9, 2007 Ok. Let's see what I've got so far. 1) I have changed plugs, no difference. No oil on the old plug, just wet from gasoline. 2) I listened to the injector, a steady clicking sound, seems ok. No leaks from the injector. 3) I have compression (didn't need to get a nervous breakdown after all since I timeserted my -93 after curing the burned exhaust valve on the no. 1 cylinder) 4) No coolant leaks 5) No codes not even a P0300 code The only things that remains is either a coil (this is a coil assembly so I don't have the possibility to switch between them like one could on the -93) or the ignition control module. To recapitulate what's wrong: When I start the car everything is fine, 1100 rpms fast idle, after a little while the idle goes down to about 900 rmps, then I can one in a while hear and feel a slight miss. When idle is normal (cold or hot engine) about 650 rpms the miss is more pronounced and feels and hears just like a occasional "dead" miss. Just like an ignition miss. I think it's the coil pack since I thought I heard ticking just like arching sitting in the car idling, when I got out I couldn't hear it any more of course.... Is there a way to test the coil pack and the ignition control module? Shouldn't any codes be set? Another thing, is there a possibility that it could be the crankshaft position sensors or the camshaft position sensor? Just a thought because I recently had the car undercoated and think this could perhaps be related..not sure since I have had a slight tremble once in a while since I bought it whitch could indicate that something was going bad and finally got worse Link to comment Share on other sites More sharing options...
Ranger Posted December 9, 2007 Report Share Posted December 9, 2007 Is there a way to test the coil pack and the ignition control module? Shouldn't any codes be set? http://www.thetoolwarehouse.net/shop/WAE-76560.html Not positive, but I don't think that a CKP or camshaft position sensor would cause a misfire. Link to comment Share on other sites More sharing options...
KevinW Posted December 10, 2007 Report Share Posted December 10, 2007 The only things that remains is either a coil (this is a coil assembly so I don't have the possibility to switch between them like one could on the -93) I believe the front and rear ignition coil assemblies are interchangeable (though they differ in colour). ___________________________________________________ Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 10, 2007 Report Share Posted December 10, 2007 Yes, I had a problem with a coil not firing recently and the plug was wet, replaced the coil and the roughness went away. Definately look at the coil. However I was getting a misfile P030x code. 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...
Logan Posted December 10, 2007 Report Share Posted December 10, 2007 Well yes, the black and silver coils are the same. They are interchangeable. I run with a spare tested 4 coil unit in my trunk. I suggest every one else do the same. That being said. There appears to be 2 different IC module connecttion interfaces that are not compatable...they will not connect. Make sure you buy the correct one. Logan Diagnostic LLC www.airbagcrash.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
Logan Posted December 10, 2007 Report Share Posted December 10, 2007 I should add..I am surprised this cylinder is not setting a PO300 code. If this injector was recently replaced with aftermarket one, it would make sense. We have proven in the past. The aftermarket injectors do no have the same flow rate based on the computer 'on' time for the other injectors. You must replace with a GM injector or replace all with the rebuilt ones. They flow fuel differently. Flow vs. 'on' must be the same. Or, you get a dead cylinder. Or PO300. Or crappy running car. The O2 senosors cant keep upwith that.. Logan Diagnostic LLC www.airbagcrash.com www.ledfix.com www.ledfix.com/yukontaillightrepair.html www.ledfix.com/ledreplacements.html www.ledfix.com/j42385toolrental.html Link to comment Share on other sites More sharing options...
Patrick7997 Posted December 10, 2007 Report Share Posted December 10, 2007 Did I miss the part where you replaced the spark plug wire???? From the coil pack to the plug?? I'd try that before I moved on to the coil pack.... just my 2 cents... Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 10, 2007 Author Report Share Posted December 10, 2007 I should add..I am surprised this cylinder is not setting a PO300 code. If this injector was recently replaced with aftermarket one, it would make sense. We have proven in the past. The aftermarket injectors do no have the same flow rate based on the computer 'on' time for the other injectors. You must replace with a GM injector or replace all with the rebuilt ones. They flow fuel differently. Flow vs. 'on' must be the same. Or, you get a dead cylinder. Or PO300. Or crappy running car. The O2 senosors cant keep upwith that.. I haven't replaced the injectors. Will check the serials to verify that they are GM today. But they worked fine last week..only a slight tremble indicating something was not right. But now it's a miss. Can feel it when reversing into my garage.. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 10, 2007 Author Report Share Posted December 10, 2007 Did I miss the part where you replaced the spark plug wire???? From the coil pack to the plug?? I'd try that before I moved on to the coil pack.... just my 2 cents... Sorry, no wires in this system, only a straight steel tube from each coil, that works like a spark plug wire Link to comment Share on other sites More sharing options...
Patrick7997 Posted December 11, 2007 Report Share Posted December 11, 2007 Ahhh, sorry, my bad.... I didn't see the year there.... obviously you have coil on plug.... They keep changing my hours, I'm half asleep all the time.... sorry about that... Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 11, 2007 Report Share Posted December 11, 2007 Ahhh, sorry, my bad.... I didn't see the year there.... obviously you have coil on plug.... They keep changing my hours, I'm half asleep all the time.... sorry about that... Easy oversight when you have a 97 or a 96 like me, it does not come to mind.... That is why I need an 02 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...
BodybyFisher Posted December 11, 2007 Report Share Posted December 11, 2007 OK, compression is ok. I trust plugs are ok, did you check to make sure the platinum pads are in place? Did you look for carbon tracking on the plug that makes connection intermittantly? Check for cracks in the plug. Change the coil. Check the resistance of the injector against the others. Yes its ticking but it might be clogged consider that. Consider a vacuum leak also at the intake 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...
BritCaddy Posted December 12, 2007 Report Share Posted December 12, 2007 I have EXACTLY the same problem on my 99 STS. Changed the plug leads, made no difference. Eventually it threw code P0300 and I found the No. 8 plug gap totally closed up with carbon. I cleaned the plug and it seems much better, but there's still a slight miss ay idle, but no problems when revving it up. I'm going to try replacing the coil and injector next. If it's oil fouling I may try a hotter spark plug. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 13, 2007 Author Report Share Posted December 13, 2007 OK, compression is ok. I trust plugs are ok, did you check to make sure the platinum pads are in place? Did you look for carbon tracking on the plug that makes connection intermittantly? Check for cracks in the plug. Change the coil. Check the resistance of the injector against the others. Yes its ticking but it might be clogged consider that. Consider a vacuum leak also at the intake Yes, plugs were ok. No carbon tracks or cracks and the pads were in place too. I did buy a new set of plugs just to be sure but that didn't solve the problem. The injector was ticking and the plug was wet with gasline so I don't think it's clogged No signs of leaks either. I will compare the resistance of the injectors if the coil won't do the trick. A new coil is on the way. By the way what is carbon build up? Seems you guys don't do enough WOT's Don't think it's a vacuum leak. The engine don't feel like it runs lean. Have had vacuum leaks on other engines bu this feels more just like a dead miss once in a while, like a bad plug. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 13, 2007 Author Report Share Posted December 13, 2007 Is there a way to test the coil pack and the ignition control module? Shouldn't any codes be set? http://www.thetoolwarehouse.net/shop/WAE-76560.html Not positive, but I don't think that a CKP or camshaft position sensor would cause a misfire. That was a cool tool! Guess it works by sensing the electromagnetic fields around the coil. Do you know of anyone who have tried it? Link to comment Share on other sites More sharing options...
Ranger Posted December 14, 2007 Report Share Posted December 14, 2007 That was a cool tool! Guess it works by sensing the electromagnetic fields around the coil. Do you know of anyone who have tried it? No, can't say as I do. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 19, 2007 Author Report Share Posted December 19, 2007 I've got the new coil pack... After installing it I tried to start..battery was dead, charging it now and will have to wait until tomorrow to see if the new pack did any difference. The car has been sitting for almost 4 weeks now... First one week wait for the plugs, then 1,5 week for the coil pack. Then I was ill for a week.. This autumn and winter hasn't been good for me I'll keep my fingers crossed and hopefully you will too. Link to comment Share on other sites More sharing options...
Jan Olsson Posted December 20, 2007 Author Report Share Posted December 20, 2007 Finally back on the road again! It was the coil pack or the ignition control module. Don't know which since I replaced the entire assembly (coil pack and module) with a new one. One good thing though is that I discovered (when changing the plugs for a start) that the old ones were improperly gapped. Feels like it got even more of a punch than usually! But then again I have had to drive wifeys Jeep Cherokee with 177 bhp..and that could of course make some difference Thanks for all support! Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 20, 2007 Report Share Posted December 20, 2007 Finally back on the road again! It was the coil pack or the ignition control module. Don't know which since I replaced the entire assembly (coil pack and module) with a new one. One good thing though is that I discovered (when changing the plugs for a start) that the old ones were improperly gapped. Feels like it got even more of a punch than usually! But then again I have had to drive wifeys Jeep Cherokee with 177 bhp..and that could of course make some difference Thanks for all support! Hey that is great, its a shame you didn't get a definitive reason for your problem. When you get a chance, I would appreciate it greatly if you would swap the old coil back in and see if that was your problem. That info would be terrific to know (not that I am trying to put you to work but your experience is good to know), Mike 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...
Jan Olsson Posted December 20, 2007 Author Report Share Posted December 20, 2007 Finally back on the road again! It was the coil pack or the ignition control module. Don't know which since I replaced the entire assembly (coil pack and module) with a new one. One good thing though is that I discovered (when changing the plugs for a start) that the old ones were improperly gapped. Feels like it got even more of a punch than usually! But then again I have had to drive wifeys Jeep Cherokee with 177 bhp..and that could of course make some difference Thanks for all support! Hey that is great, its a shame you didn't get a definitive reason for your problem. When you get a chance, I would appreciate it greatly if you would swap the old coil back in and see if that was your problem. That info would be terrific to know (not that I am trying to put you to work but your experience is good to know), Mike I can see that it would be nice to know. The only reason I didn't try the new coil pack with the old ICM was that both the module and the ICM came as a unit. You'll never know with electronics. What if the old coil messes up the new ICM or vice versa? Call me a coward Link to comment Share on other sites More sharing options...
BodybyFisher Posted December 20, 2007 Report Share Posted December 20, 2007 Finally back on the road again! It was the coil pack or the ignition control module. Don't know which since I replaced the entire assembly (coil pack and module) with a new one. One good thing though is that I discovered (when changing the plugs for a start) that the old ones were improperly gapped. Feels like it got even more of a punch than usually! But then again I have had to drive wifeys Jeep Cherokee with 177 bhp..and that could of course make some difference Thanks for all support! Hey that is great, its a shame you didn't get a definitive reason for your problem. When you get a chance, I would appreciate it greatly if you would swap the old coil back in and see if that was your problem. That info would be terrific to know (not that I am trying to put you to work but your experience is good to know), Mike I can see that it would be nice to know. The only reason I didn't try the new coil pack with the old ICM was that both the module and the ICM came as a unit. You'll never know with electronics. What if the old coil messes up the new ICM or vice versa? Call me a coward OK chicken..... I actually forgot that you have COP..... Glad you got it fixed... 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...
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