Nosser Posted July 20, 2009 Report Share Posted July 20, 2009 Hi all, Been lurking here for a little while but this is my first post. I recently picked up a 93 Regal Custom with 40k original miles (score!) from my local police auction. Got her home today, charged the battery and started her up to be greeted by a definite misfire. It starts up instantly and has no trouble staying running (no throttle required) but idle is slightly lumpy and sounds odd. Misfire continues up through rev range, it's not just at idle, also no check engine light. Since I figured it would be easy and cheap to test I grabbed a new coil pack and tried it in each of the three positions - no dice. Just to confirm firing order is correct, if you are looking at the coils from the passenger side fender, plug wires currently are 6-3-2-5-4-1 from left to right. Is this correct? My next steps would be pulling plugs (back bank looks fun!) and ohming the injectors, but before I got too deep into diagnosis I thought I would post here to see if there are any really common problems that would lead to these symptoms. If not and I am on the right track - can someone provide proper resistance spec for the injectors? Thanks in advance! Quote Link to comment Share on other sites More sharing options...
sloick Posted July 20, 2009 Report Share Posted July 20, 2009 a basic tune up first. its sat for a long time for sure so go through and check for vacuum leaks. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted July 20, 2009 Report Share Posted July 20, 2009 in order: tune-up. USE AC DELCO Plugs. ACD Rapidfires for you car are worth the money. Bosch branded plugs will fail in our type of coil system. don't forget to GAP them and antisieze the threads inspect your plug wires. replace or repair any if found bad. you could do a compression check while you have the plugs out. Autozone has a loaner compression tester than works well enough. Ohm check your injectors to make sure you don't have a bad one. harbor freight has a cheap multi-meter if you need it. Quote Link to comment Share on other sites More sharing options...
cubsfan24 Posted July 20, 2009 Report Share Posted July 20, 2009 My next steps would be pulling plugs (back bank looks fun!) Actually I did the back plugs on a 94 regal 3800 and it was easy. Not a lot of room but you can easily got a ratchet behind there with a short extension. At least you don't have to rock the engine forward like you do on a 3100. I don't have any other suggestions other than giving it new plugs/wires. Quote Link to comment Share on other sites More sharing options...
91LuminaEuro Posted July 20, 2009 Report Share Posted July 20, 2009 I agree with everythign that has already been said. New plugs and wires are a must for a car that sat that long! Also like they said, check for a vacuum leak, if it sat things may have dry rotted an cracked! It may also be nice to run some fuel injector cleaner through it as well with your next full tank of gas! Quote Link to comment Share on other sites More sharing options...
Nosser Posted July 20, 2009 Author Report Share Posted July 20, 2009 Wow, this is an active forum, didn't expect to get so many replies so quickly, thanks! Delco plugs and new wires it is - regarding ohm checking the injectors - what should they be? Also found the post about the rear heat shields sometimes causing problems - I'll pull those if present. Since no one has called it out I'm assuming firing order is correct. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted July 20, 2009 Report Share Posted July 20, 2009 i don;t know about the firing order... but the coil number sounds correct. Quote Link to comment Share on other sites More sharing options...
Nosser Posted July 27, 2009 Author Report Share Posted July 27, 2009 Update - installed a set of Delco wires and Rapidfire plugs yesterday. Plugs that came out were wet and smelled of fuel on cylinders 1 and 4. Restarted, miss still there, pulled new #1 plug and it's obviously not firing. I threw the spare coil I have (brand new) on the 1,4 spot - made no change. So I am now thinking it probably the ignition module. Is this a common failure mode - can one coil position on the module die while the other two continue to work? If so I think that would be pretty definitive that the module is the culprit, but hopefully someone here can confirm before I plunk down the cash. Quote Link to comment Share on other sites More sharing options...
Nosser Posted August 2, 2009 Author Report Share Posted August 2, 2009 Headed to the JY this morning because I wasn't about to drop $150 on the ignition control module without being sure that was the problem - long story short new ICM completely fixed miss and she runs like a top now. Quote Link to comment Share on other sites More sharing options...
slick Posted August 2, 2009 Report Share Posted August 2, 2009 Good deal! Quote Link to comment Share on other sites More sharing options...
ZeroDCX Posted August 5, 2009 Report Share Posted August 5, 2009 Common problems with the 3800 Series 1 motor also include the Crankshaft Position Sensor. My symptoms sounded the same as yours two years ago. Just a thought. Quote Link to comment Share on other sites More sharing options...
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