Close



Results 1 to 14 of 14
  1. #1
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default 3.8L V6 Random Stalling While Driving Restart After Cool Down

    The end of last summer we took our '85 LTD wagon up north on vacation. It was still reasonably hot during the trip even though it was late in the season. It is about a six hour ride back and forth.

    On the way up the car ran fine as well as while we were up north. Coming back down after driving for about 2-3 hours going down the highway the car just stalled and quit (of course this is while my wife, son, dog, and MIL are in the car with all of our stuff). After doing a cursory check under the hood I didn't see anything obvious. I did have fuel at the CFI, but what pressure I do not know. The car would turn over just fine, but it wouldn't start. As any good person driving a Ford with TFI I had a spare ignition module which I installed. No dice. With the limited tools I had it appeared I wasn't getting spark. Wife and son walk to the gas station down the street while I ponder my next move. After checking a few more things I have my MIL crank the engine while I check something and it starts up (this is after about 20 minutes or so). Elated I go pick up my wife and son and we get back on the road.

    Everything is going fine and then about 1 hour later the same thing happens. Pull off the road and same thing. Again after sitting for a while it starts back up. Since changing the TFI module seemingly had no effect I then focused on the coil. I located one at a parts store and swapped it out. Ran fine. After this it was getting dark and cooling down. Another two hours of driving and just as we are getting off the highway by our house it stalls again. Again same thing won't restart until sitting for a while.

    Sooo, since it is hard to diagnose a problem when it is so hard to recreate I am about at the point where I am willing to just throw parts at it (as if I weren't already there). My next step was to replace the distributor pickup coil unless anyone has any other suggestions. Clearly something is getting hot, failing, cooling down, and then resumes working. Definitely sounds like an electrical component to me. Since I had fuel at the CFI (again could only check for fuel not the actual pressure) I am assuming the fuel pump(s) are okay. Yes I realize that new parts (ignition module and coil) can be bad, but changing them didn't really seem to change anything.

    This engine will eventually be replaced so I don't want to go crazy, but it needs to provide a couple more years of reliable service before that happens.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  2. #2
    FEP Supporter Broncojunkie's Avatar
    Join Date
    Jan 2015
    Location
    Barboursville, WV
    Posts
    751

    Default

    I would suspect the pickup in the distributor. You can pick up a reman distributor pretty cheap at the mcparts store. I just got one at NAPA the other day for $51, iirc. Or someone on here is sure to have a good used one lying around. Or you can pull yours apart and replace the pickup. I think you will need to press the gear on and off. I would try and find a good used one from a member here, since you're planning on replacing the engine in the near future. I have one or two lying around I would give you, but for the life of me, I can't find them. It was easier for me to pick up one from the parts store than dig them out lol
    Last edited by Broncojunkie; 03-01-2018 at 02:47 PM.

  3. #3
    FEP Supporter webestang's Avatar
    Join Date
    May 2009
    Location
    St. Louis, MO.
    Posts
    4,603

    Default

    Could still be the TFI. I went through 3 TFI's till I finally put it on the fender apron with relocation kit. Worst thing Ford ever did was place the TFI's on the dizzy.

    Scotty
    1985 Fox Notch 4-banger Ranger tube header Eastwood Royal Blue
    1988 Fox LX 5.0 AOD Vert BBK 170mph speedo Candy Apple Red
    1999 Mustang Coupe V6 Auto Chrome Yellow -Rebuild Coming Soon.
    1996 Crown Vic LX 4.6 Silver "Gort" Daily Driver

    Past Pony's.....
    68 Coupe Inline-6 3-Speed-Man. Primer
    78 II Hatch 302 3-Speed-Auto Sunroof Black
    81 4-Eye Coupe 4-Banger 4-Speed-Man. White

  4. #4
    FEP Supporter Broncojunkie's Avatar
    Join Date
    Jan 2015
    Location
    Barboursville, WV
    Posts
    751

    Default

    Quote Originally Posted by webestang View Post
    Could still be the TFI. I went through 3 TFI's till I finally put it on the fender apron with relocation kit. Worst thing Ford ever did was place the TFI's on the dizzy.
    True. I bought one at the parts store and it was bad. They argued with me and told me I was crazy, after they bench tested it and it showed ok. Drove me nuts. I tested and retested everything, then just started replacing parts. My tests kept pointing back to the tfi. Finally, I took it to another store and they bench tested it again. It showed good, so I had them run the test a few times in a row and it failed. They finally apologized and grabbed another one off the shelf. It was bad. They had 3 in stock and none were usable. So yeah, don't rule out the module! Have them bench tested at the store and go from there.

  5. #5
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default

    I appreciate the input. The TFI module I had was just a cheap Chinese version that I picked up just to have a spare so it could be bad. The only thing that makes me think it isn't TFI related is the first time it quit. I put the replacement module in and nothing changed. It wasn't until after the car cooled down that it started up again. I would think if it were the TFI module and the new one was bad that it wouldn't have started back up at all. That said I may invest in a Motorcraft module although from what I have read they might not be any better than the cheap aftermarket modules anymore. Looking around some more I also see Accel, MSD, and Pertronix units probably aren't any better either. I'd be willing to pay the money for a quality unit if one could be had. That said, what could be so complicated about these that makes it so hard to build a good one? I've never had an ignition module tested in a store, but I have heard that they should test it multiple times to make sure it heats up enough to replicate actually running on the car.

    I appreciate the offer on the distributor. Since I am cheap AND I enjoy the challenge I'll probably tear mine apart to replace the pickup. It looks like you can get a Motorcraft replacement for about $25.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  6. #6
    FEP Supporter webestang's Avatar
    Join Date
    May 2009
    Location
    St. Louis, MO.
    Posts
    4,603

    Default

    My first TFI replacement did the same thing. After it cooled down it started and would bench test fine. They say that the heat absorbing grease should take care of the heat but it did not. Every time it got to hot it would cut off but after a cool down, started right up. So I got a relocate kit and put a Ford TFI module and it works great. I also did replace the dizzy with a new one.
    Ford even started putting the TFI on the apron after to many complaints.

    Scotty
    1985 Fox Notch 4-banger Ranger tube header Eastwood Royal Blue
    1988 Fox LX 5.0 AOD Vert BBK 170mph speedo Candy Apple Red
    1999 Mustang Coupe V6 Auto Chrome Yellow -Rebuild Coming Soon.
    1996 Crown Vic LX 4.6 Silver "Gort" Daily Driver

    Past Pony's.....
    68 Coupe Inline-6 3-Speed-Man. Primer
    78 II Hatch 302 3-Speed-Auto Sunroof Black
    81 4-Eye Coupe 4-Banger 4-Speed-Man. White

  7. #7
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,292

    Default

    Thing is when prob first showed up. Happen before or on trip?
    It is hard to diagnose being intermittent.

    Will never forget similar storys.
    One is humbled badly when car quits way out there in BFE.
    It was what got me interested in carburetors as a 9-10y old.

    Going up north. Taquam. Falls, Alpena. Summer.
    1962 1963?. Family trip. No record of year.
    1961 Chevy Impala 2 door almond beige 283 2bbl powerglide dad bought new.

    Ran fine going up to falls. Came back down. Stayed overnite in Alpena.
    Tanked up. Bought bad gas. Dirty. Prob dont sell much up there.
    Anyway, started stalling out just as yours.
    Dad had to get out the rubber mallet and tapped the carb when car conked out.
    Then it would start and run for 50-100 miles. Pinconning, Bay City, Flint.

    Car was taken to grampa's old neighborhood mechanic Harley Ferguson, in Detroit.
    He disassembled the carb and cleaned it. They let me watch.
    Remember Harley said "dirt in carb".
    Dad said it must have been the gas bought in Alpena.

    Same deal with me.
    1970 VW, 1970's trip to Chicago from Detroit.
    Destination: JC Whitney warehouse to exchange leaking tube header set.
    Coming back, tanked up at a truck stop. Bad fuel.
    Engine stalled on ramp getting back onto I-94 eastbound.
    Smelled diesel out exhaust. Absolutely did not use the truck stop diesel pumps.
    Tow, tune up (unneeded, did it pre-trip). Insisted on draining fuel tank. Good to go.

    So may be a fuel prob. Bad load. Water, dirt.
    Fuel filter, etc.

    Would not hurt to change dist. Easier to swap the whole thing out. Plug and play.
    AZ dont have them.
    Go with Motorcraft is possible. Cap too.
    Rock Auto lists new Motorcraft DA2004 distributor 56.84 no core cheaper than Cardone reman.
    Motorcraft DU30C pickup coil is 24.79 +time removing/install.
    http://www.rockauto.com/en/catalog/f...ule+(icm),7172

  8. #8
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default

    Sounds like your dad's Impala may have had a stuck float and/or sticking or plugged needle and seat from the bad gas. Unfortunately I don't think any amount of hammer blows would have gotten my car to start. From what I recall we gassed up in Munising and hit the road. It ran fine for a few hours after that.

    I think I am just going to replace the coil, TFI module, and distributor with new Motorcraft parts and hope for the best. I can get all three from RockAuto for $150 shipped. I was going to order them last night, but I decided to sleep on it in case I changed my mind in the morning. I think I will also do the TFI relocation to the fenderwell. I see the local LKQ has a couple of 96 and 97 Thunderbirds in stock. Hopefully at least one is a V6 so I can liberate the TFI heat sink from it.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  9. #9
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,292

    Default

    Could have been those. Rubber hammers remind me of the event but unfortunately not the details.

    Another:
    One night coming home from Downriver Cruise, the Mustang started bucking like a bronco.
    Would idle or run fine floored. No go otherwise.
    Roadside carb inspection, under 7-11 lighting, revealed pieces of debris in carb bowl and in p-jet.
    Cleaned it out, car ran normal all the way back home. Saved the debris for inspection once home.

    Later, magnify glass confirmed black carb bowl gasket flakes.
    My theory:
    Fuel slosh made them float in the bowl then block the primary jet when it came online.
    No mid range cruise.
    Secondary jet provided WOT fuel because all the debris was sucked up by the primary jet.
    Fuel for idle was somehow not blocked.

    Also had the dist thing, coil pickup, intermittent stall, hesitation.
    Coil pickup is mounted on dist adv plate. Wires exit dist housing thru strain relief to connector.
    Wires from the coil pickup fatigued and cracked at the strain relief.

  10. #10
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default

    Well I've had the parts sitting in my house long enough waiting for the snow to stop when we just got more today. I was able to make it to the junkyard last weekend (sans snow) to liberate a TFI heat sink. Much to my chagrin when I lifted the hood on the '96 T-Bird there I realized they had switched to DIS that year. You wouldn't believe how hard it is to find a Ford vehicle with a distributor in a junkyard these days. I finally wandered to the van and truck section and found a mid 90's Econoline with a SBF and a remote mounted TFI module and the rattiest looking TFI module heat sink you have ever seen. I cleaned most of the scabby corrosion from the heat sink and got to making my own remote mount for this. Sure I could order a pre-made relocation kit and that would be easier, but I'd rather build it myself.

    I think I found a place on the driver's side fenderwell where I can mount the heat sink and since there are 10,000 holes there already from the factory I am sure I can find at least one to mount the heat sink to so I'll only have to add one more hole to properly mount it. It looks like I will have to lengthen the current TFI harness about a foot to reach its new location. Shouldn't be too bad. I started collecting the parts to create the relocation harness to go from the dist pickup coil to the ignition module. I can only hope it will stay cool enough on the fenderwell. Anything has to be better than right on the distributor where it is about 5 degrees cooler than the surface of the sun though.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  11. #11
    FEP Supporter webestang's Avatar
    Join Date
    May 2009
    Location
    St. Louis, MO.
    Posts
    4,603

    Default

    I think that relocated TFI should be fine. Also still put heat grease on the back of the TFI. Mine has been on the fender for 5 years now and has not overheated once.

    Scotty
    1985 Fox Notch 4-banger Ranger tube header Eastwood Royal Blue
    1988 Fox LX 5.0 AOD Vert BBK 170mph speedo Candy Apple Red
    1999 Mustang Coupe V6 Auto Chrome Yellow -Rebuild Coming Soon.
    1996 Crown Vic LX 4.6 Silver "Gort" Daily Driver

    Past Pony's.....
    68 Coupe Inline-6 3-Speed-Man. Primer
    78 II Hatch 302 3-Speed-Auto Sunroof Black
    81 4-Eye Coupe 4-Banger 4-Speed-Man. White

  12. #12
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default

    I hope so. I still have to drill one hole for the TFI heat sink to mount to the inner fender. I do have my old Radio Shack tube of heat sink compound to coat the back of the module with so I should be covered there.

    I constructed the wiring harness to go from the distributor to the TFI this past weekend using this as a guide: https://www.youtube.com/watch?v=U-O0SVtt8zk and I fabbed up a cover plate where the TFI used to mount on the distributor. Also, in case anybody is wondering for future reference, the spade connectors that come off of the TFI and plug into the pickup in the distributor are .188" wide. I found some female connectors that were the correct size (Dorman 85446) https://www.dormanproducts.com/p-165...origin=keyword and they fit well on the TFI module. I could not find the corresponding male connector in a .188" width at the store I was at so I just filed down some .250" width connectors and they appear to be nice and tight in the distributor pickup. They do make a .188" male terminal though if you can find them: https://www.dormanproducts.com/p-207...origin=keyword

    When I went to lengthen the harness that plugs into the TFI module I found that three of the wires were shielded. Not wanting to tempt fate I extended the shielding on those three wires using the same method as above. Hopefully it works fine.

    All that is left to do is to install the new distributor with new pickup (what I think was the root cause of all the issues). Of course my old distributor had the screw on rotor whereas the new distributor uses the press on style so I had to get a new one. I think I will keep the cap and wires as is for now. They look brand new as did the spark plugs that I replaced. I am pretty sure the woman that sold this had a complete tune up done before I bought the car.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  13. #13
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    219

    Default

    Well that wasn't too bad. Pulled the old distributor out and dropped the new one right in. Distributor cap looked brand new so I feel pretty good about reinstalling it on the new distributor. Even though I dropped the distributor in with the crank at 10 BTDC I still managed to get the timing retarded initially. I try. Got it timed and set and it should be good to go. If this stalling issue turns out to be the fuel pump I am going to be pissed. Oh yeah. Better remind myself to put my fuel pressure gauge in the car if it happens again.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  14. #14
    FEP Supporter webestang's Avatar
    Join Date
    May 2009
    Location
    St. Louis, MO.
    Posts
    4,603

    Default

    Sounds like your good to go. I hope as well it's not the fuel pump but every time I've had a pump problem they failed completely.
    Wishing you luck.

    Scotty
    1985 Fox Notch 4-banger Ranger tube header Eastwood Royal Blue
    1988 Fox LX 5.0 AOD Vert BBK 170mph speedo Candy Apple Red
    1999 Mustang Coupe V6 Auto Chrome Yellow -Rebuild Coming Soon.
    1996 Crown Vic LX 4.6 Silver "Gort" Daily Driver

    Past Pony's.....
    68 Coupe Inline-6 3-Speed-Man. Primer
    78 II Hatch 302 3-Speed-Auto Sunroof Black
    81 4-Eye Coupe 4-Banger 4-Speed-Man. White

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •