Old car fan Posted December 4, 2016 Share Posted December 4, 2016 (edited) I have a 2001 Crown Vic Police Interceptor with 198K miles.I've been dealing with this stumbling problem for at least a year if not more. It seems like this is a common problem. It doesn't throw any codes. I've tried to get real time readings with my code reader and nothing.It stumbles at the usual 45-50 mphs in 4th with part throttle or at lower speeds in lower gears going up a grade. It happens more with passengers. It doesn't always do it. It even seems to stumble a bit at WOT. It sort of feels like its not getting enough fuel.It most of the times runs great and gets around 18 mpgs in combined driving.I've changed the fuel and air filters. I've changed the plugs and cleaned the MAF. I've cleaned all the electrical connections at the coils. The coils are OEM but I don't know how old they really are. They have green Motorcraft logos on them. Visually they look fine as well as the boots.I'm leaning toward needing coils but I've read it could be the MAF or the TPS. I don't have money to throw at guesses. I really want to solve this once and for all. I used a good quality Matco code reader and was even trying to get soft codes but got nothing. It's frustrating.Any ideas?Thanks.DJ Edited December 4, 2016 by Old car fan Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted December 4, 2016 Share Posted December 4, 2016 Your description sounds like a failing coil. You would have no way to find it without some diagnostic equipment. It maybe worth your while to pay for a diagnosis. A power balance test needs to be run and see which cylinder falls out. If your scanner can read mode 6 data. Sometimes it can show which cylinder is higher than others as far as misfire counts. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 4, 2016 Author Share Posted December 4, 2016 No as far as I know my scanner doesn't read mode 6 data. My problem is I don't have time to stop by the shop I trust as they aren't open Saturdays and they're usually closed by the time I pass them by on my way home from work during the week. I'd really like to be sure without a doubt it's the coils before shelling out nearly $300 for a set of new OEM's. Thanks. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted December 4, 2016 Share Posted December 4, 2016 No as far as I know my scanner doesn't read mode 6 data. My problem is I don't have time to stop by the shop I trust as they aren't open Saturdays and they're usually closed by the time I pass them by on my way home from work during the week. I'd really like to be sure without a doubt it's the coils before shelling out nearly $300 for a set of new OEM's. Thanks. I understand not wanting to throw parts at it. However with out correct diagnosis you will be guessing. Most dealers are open at least half a day on Saturday. They normally charge an hour fee. So probably $95-110 . Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 4, 2016 Author Share Posted December 4, 2016 I may have to go to a dealer then. I was hoping it would get bad enough to eventually throw a code. I've even tried to prolong a stumbling event to make it throw a code but no luck. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted December 4, 2016 Share Posted December 4, 2016 That is a good theory and I have done that. However, sometimes when the coils fail, they create radio frequency interference and freak the pcm out which could mislead you. Especially if the failing coil is closest one to the pcm. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 5, 2016 Author Share Posted December 5, 2016 (edited) I'd almost be happy with getting any code at this point but a wrong code would really frustrate me. Thanks for that tip. I miss having a daily driver with points and a carb. There's little to go wrong and repairs are cheap. Edited December 5, 2016 by Old car fan Quote Link to comment Share on other sites More sharing options...
theoldwizard Posted December 5, 2016 Share Posted December 5, 2016 Eight coils, especially Motorcraft coils, is a lot of money (>$550 !). Out of the box theory. It could be an A/C clutch slipping and then re-engaging. Disconnect the A/C clutch and drive for a few days and see if that makes a difference. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 5, 2016 Author Share Posted December 5, 2016 I'm sure it's not the A/C clutch as I've had it happened with the A/C off. I've priced the coils around and a set of OEM's can be bought for less than $300. I would not keep the car any longer if I had to spend $500 as that is the spending limit I have set. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 7, 2016 Author Share Posted December 7, 2016 I was told it could be the torque converter causing it. It happens at just over 45 mph and when I lightly tap the brake pedal it unlocks it and the stumble goes away. The only thing though it can sometimes stumble at lower speeds as well. At least a fluid change and flush may be needed. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted December 7, 2016 Share Posted December 7, 2016 It can be determined if it's engine or not with a power balance test. Otherwise you are guessing. At low rpm and converter locked the engine is under heavy load. When the converter unlocks it eases the load. Most of the time it's ignition issues from a coil. However could be other things. That's why it's so important for proper test. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted December 7, 2016 Author Share Posted December 7, 2016 Good advice Fordtech but I have a feeling it would take more money and time than I could afford. I haven't changed the transmission fluid since buying the car and I've put nearly 40K miles on it so that may be overdue since who knows when it was changed last. I'll see how it drives after I get a chance to do a fluid flush and change. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted January 25, 2017 Author Share Posted January 25, 2017 I think I have problem solved. I replaced all the COP's with new Densos and I haven't had an issue since. It runs better than it has for a long time.It was an easy job taking less than 30 minutes. I think I spent more time opening the boxes and removing the coils from the plastic bags than R&R-ing everything. Most of the clips on the connectors for the injectors are broken. One of them must have gotten knocked loose and lost contact when driving last night. That got me a little worried and made me think at first a brand new coil when bad. It wasn't and the culprit was easy to find.Now I'm back to enjoying how nice it is to drive this car.I'm coming up on 200K and this car feels like it easily has less than half than mileage. Quote Link to comment Share on other sites More sharing options...
fordtech1 Posted January 25, 2017 Share Posted January 25, 2017 That's good news. Those clips break so easy. Easiest thing is to take a small zip tie run through the connector and around the injector and pull snug. 1 Quote Link to comment Share on other sites More sharing options...
Old car fan Posted January 26, 2017 Author Share Posted January 26, 2017 Thanks for the reminder. I had read about the zip tie fix before. Luckily none of the connectors on the COP's broke. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted February 3, 2017 Author Share Posted February 3, 2017 I've been driving it for about week and it's been running great. It has more power now than I can remember it having. I filled up once but half of the driving from that tank was on the old coils. I almost got 17 mpg on that tank. I've never gotten over 19 mpg so I'm hoping to see something better on the next fill up. 1 Quote Link to comment Share on other sites More sharing options...
twintornados Posted February 3, 2017 Share Posted February 3, 2017 I've been driving it for about week and it's been running great. It has more power now than I can remember it having. I filled up once but half of the driving from that tank was on the old coils. I almost got 17 mpg on that tank. I've never gotten over 19 mpg so I'm hoping to see something better on the next fill up. . Good to hear, keep us posted. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted February 3, 2017 Author Share Posted February 3, 2017 You bet. This site is great. 1 Quote Link to comment Share on other sites More sharing options...
Old car fan Posted February 16, 2017 Author Share Posted February 16, 2017 (edited) Well at my last fill up I got 17.4 mpgs. Not great since I expected a little better. It's more like what I used to get with old coils but it does have more power and it does run better, so I'm not disappointed. I'm wondering if by disconnecting the battery for a while might reset the computer and then running cleared of any soft codes might re-calibrate things? Edited February 16, 2017 by Old car fan Quote Link to comment Share on other sites More sharing options...
twintornados Posted February 16, 2017 Share Posted February 16, 2017 (edited) Well at my last fill up I got 17.4 mpgs. Not great since I expected a little better. It's more like what I used to get with old coils but it does have more power and it does run better, so I'm not disappointed. I'm wondering if by disconnecting the battery for a while might reset the computer and then running cleared of any soft codes might re-calibrate things? . More likely, you are enjoying the renewed power and as such getting a little more liberal with the "go pedal"....give her a couple of tankfuls and ease up on the loud pedal and it should straighten out....glad she is running better. Edited February 16, 2017 by twintornados Quote Link to comment Share on other sites More sharing options...
Old car fan Posted February 16, 2017 Author Share Posted February 16, 2017 No not really. I've been driving it somewhat conservatively as always with no jackrabbit starts. I have accelerated briskly a few times to get on the freeway just to see how good I can get up to speed but no WOT. I know the gas has something to do with it but it's just the usual 10% blend like everywhere. Quote Link to comment Share on other sites More sharing options...
twintornados Posted February 16, 2017 Share Posted February 16, 2017 (edited) No not really. I've been driving it somewhat conservatively as always with no jackrabbit starts. I have accelerated briskly a few times to get on the freeway just to see how good I can get up to speed but no WOT. I know the gas has something to do with it but it's just the usual 10% blend like everywhere. . Not sure for your area, but here in Central NY, we have gas stations that sell gasoline with no ethanol....my car runs great and I also get it for my lawn care toys... Non-ethanol gas finder, selected for WA area.... http://www.pure-gas.org/index.jsp?stateprov=WA Edited February 16, 2017 by twintornados Quote Link to comment Share on other sites More sharing options...
akirby Posted February 16, 2017 Share Posted February 16, 2017 In GA you can only find pure gasoline at or near Marinas. Quote Link to comment Share on other sites More sharing options...
Old car fan Posted February 17, 2017 Author Share Posted February 17, 2017 The real gas around here in WA is about at least a buck more a gallon than the corn gas. I have to wonder if the real gas might get a bit stale at those prices. Also I wonder if one fuel outlet has more alcohol than another despite they post 10% on their pumps. Quote Link to comment Share on other sites More sharing options...
twintornados Posted February 17, 2017 Share Posted February 17, 2017 That sucks man....We have "pure gas" options at my Fastrac if you use premium...in neighboring Camden NY, their new Fastrac also has "pure gas" in the 87 octane and it is 25 cents more per gallon. Quote Link to comment Share on other sites More sharing options...
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