Ranger Posted May 21, 2005 Report Share Posted May 21, 2005 This afternoon when I started the car to go to work I had a pretty bad misfire. Not long after I got the flashing SES light. Pulled the codes and found P0300 History (misfire). It settled down after about a mile. After reading this post http://caddyinfo.ipbhost.com/index.php?showtopic=6092&st=0 the other day, I guess I will have to pull and clean the dielectric grease off all the plugs and wires tomorrow (they are only a few months old). Link to comment Share on other sites More sharing options...
PAUL T Posted May 22, 2005 Report Share Posted May 22, 2005 If you could isolate which cylinders are missing you might find out you need a coil. Mine drove me nuts for 6 months. Link to comment Share on other sites More sharing options...
Ranger Posted May 23, 2005 Author Report Share Posted May 23, 2005 I pulled the plugs today and wiped out the plug wires. Wanted to check the plugs gaps and spent :30 min. looking for the specs in the service manual Never did find it. Looked in my daughters '99 manual and found it in 30 seconds. Who ever wrote that manual should be whipped. It would be pretty hard to determin which cylinder it is because it doesn't last long. We went out for dinner tonight and it ran pretty rough when I started it but smoothed out within a minute. It's starting to piss me off. Link to comment Share on other sites More sharing options...
KHE Posted May 23, 2005 Report Share Posted May 23, 2005 It can be tough to find things in the shop manual. Usually the plug gap is on the emissions label under the hood. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
KHE Posted May 23, 2005 Report Share Posted May 23, 2005 It can be tough to find things in the shop manual. Usually the plug gap is on the emissions label under the hood. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
cdictas Posted May 23, 2005 Report Share Posted May 23, 2005 Ranger, Do a search under my name for some helpful tips. Good Luck Link to comment Share on other sites More sharing options...
Ranger Posted May 23, 2005 Author Report Share Posted May 23, 2005 Ranger, Do a search under my name for some helpful tips. Good Luck I did a search and I assume you are talking about using a stethescope to listen for arcing. I'll try that next time it misfires. Started it up this morning and it was smooth as glass. I just got a physical at work and was able to sweet talk the physicians Assistant into getting me a stethescope. Apparently one fell off a truck . I replaced the listening device on the end with a copper tube and a rubber tip on the end of it with a hole in it. WOW, it is amazing the things you can hear going on inside your engine with that thing. It would make a faulty fuel injector easy to diagnose as you can hear the injectors clicking as they open and close. It should make easy work of an arcing coil. Thanks for the tip. Link to comment Share on other sites More sharing options...
cdictas Posted May 23, 2005 Report Share Posted May 23, 2005 Ranger, I also had a problem with a brand new spark plug. You may want to do a resistance check on each of your spark plugs. Depending on whether you have a DVM or an analog meter, you should get readings greater than a megohm (on DVM) or no reading (on an analog meter). My brand new spark plug measured 7000 ohms. Now I know your thinking I didn't change the plugs, spark plugs can go bad over time. Just something to think about. Chuck Link to comment Share on other sites More sharing options...
Ranger Posted May 24, 2005 Author Report Share Posted May 24, 2005 Thanks Chuck. It is rather intermitent. Only happens occasioanally at start up and does not last long so I don't suspect plugs, but I'll keep it in mind if I can't nail it down. Link to comment Share on other sites More sharing options...
Logan Posted May 24, 2005 Report Share Posted May 24, 2005 When the check engine lamp is flashing....thats a pretty bad misfire. Its the computer warning you the its bad enough to damage the cat con... Could be ....... plug wire coil module Even saw one the other day....car was a flood car and sat for a year. The sepentine belt had set up and was dancing all over.....causing PO300. Logan Diagnostic LLC www.airbagcrash.com www.logandieselusa.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...
WarrenJ Posted May 24, 2005 Report Share Posted May 24, 2005 How about using the DIC to do a "snapshot?" Regards, Warren There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
Ranger Posted May 24, 2005 Author Report Share Posted May 24, 2005 When the check engine lamp is flashing....thats a pretty bad misfire. Its the computer warning you the its bad enough to damage the cat con... Could be ....... plug wire coil module Even saw one the other day....car was a flood car and sat for a year. The sepentine belt had set up and was dancing all over.....causing PO300. Yeah Logan. It was flashing that morning and was a pretty bad misfire but only lasted a minute or so. The next morning it felt like a slight misfire with no light at all and also went awy very shortly thereafter. Yesterday morning it was perfectly smooth. I think she's just toying with me. Like I said, plugs and wires are new (A/C Delco). Guess I'll have to keep the stethescope handy next time I start it. Link to comment Share on other sites More sharing options...
adallak Posted May 24, 2005 Report Share Posted May 24, 2005 Ranger, Did you notice a corellation between misfire and humidity (rainy day)? One of wires could leak high voltage when it is humid and stop leaking as soon as engine heats up. Just a suggestion... The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
Ranger Posted May 25, 2005 Author Report Share Posted May 25, 2005 No, I don't think humidity was a factor. Haven't had much of that this spring. Link to comment Share on other sites More sharing options...
mike5514 Posted May 25, 2005 Report Share Posted May 25, 2005 Am I correct in assuming that the miss only occures in open loop? If that is the case then whatever the miss is, it is picked up by the computer and adjusted out. So I would expect to find a lean Fuel air mixture. Saying this I would expect a injector,iac,or maf in that order. Mike Link to comment Share on other sites More sharing options...
Ranger Posted May 25, 2005 Author Report Share Posted May 25, 2005 Yes Mike, you are correct. It only happens occasionaly at startup (maybe 2 or 3 times so far) and only lasts for a minute or so. Only once was bad enough to trip the SES light. Link to comment Share on other sites More sharing options...
Ranger Posted May 28, 2005 Author Report Share Posted May 28, 2005 It can be tough to find things in the shop manual. Usually the plug gap is on the emissions label under the hood. I never did find that emisions label until today. It is cleverly hidden, literally under the hood behind the grill <_ it shows the plug gap at .060 but car came with my daughters manual .050. i guess changed plugs.> Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.