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Hello,
I have come into what seem to be a major gremlin with my '07. This started after I did a hard pull accelerating on the on-ramp. (It was probably the highest I have ever had the tach up to) Next day, Eugene was stumbling under low acceleration until shift-point. I had trouble under load going uphill.

Note: The battery would be dead on startup every time since initial issue

-I did not find a fuel pump replacement anywhere in Eugene's records, and the pump did not sound too good to begin with, so I started there with a new fuel pump/assembly and in-line filter. This pepped the car back up instantly for a little drive around the block. Parked it, battery was flatlined after 20 min cooldown, jumped it, hard start, very rough idle, almost impossible to keep running. Backfiring, black smoke.

-Time for a new battery so I can run some real tests, tried to save the old one, she's dead, Jim. Same issues on startup, rough idle, backfiring, black smoke, difficult to gain Rev's.

-To begin consulting with the Oracle (Hayne's manual).

-Lets get into Eugene's wiring. (Ref. 0-21 part 7 Haynes Man)
1. I inspected the harness from MAFS back to throttle body assy. to the best of my ability without removing too many interfering parts. No issues found aside from some cracked loom shielding.
2. Checked for vacuum leaks via spraying carb cleaner around the throttle body, no response. Sprayed carb cleaner into the throttle body downstream of the MAFS, no response. All bolts are tight.
3. Insufficient fuel pressure? Sending unit was replaced, and operating perfectly. (Ref. 4-12 part 14) Checking the IAC. I ran a voltage test on the IAC, to find that the PCM was only sending .29V to IAC. Resistance of valve: 9.9 Ohms. We will revisit this issue later, as I took note and moved on.
4. Suspected issue with MAFS. I ran the engine in open loop with MAFS disconnected, ran great under throttle. Lifted front end up and got'em in gear and tried to let the computer relearn in open loop after having its brain shocked. Everything was fine until I had my assistant plug in the MAFS for an instant rough idle and stall out.. Hmmm... I had replaced the MAFS not long ago, but hey, check it anyways. Found an OL doing a resistance test on the heated wire. Replaced MAFS. Hallelujah!!! Right? No.

-Eugene started right up, idled fine, even went for a cruise around the block and brought him up to temp. Parked it, and got ready to wrap up when, uh oh. Now that he is warmed up, he does not want to stay running. Revs up just fine, but unable to hold idle without foot assistance. Took the air filter out for shits'n'giggles, and he held idle around 700 rpm, not dying but noticeably has bronchitis.
-Time to break out the multimeter again. I back-pinned the IAC to see what instructions it was receiving from PCM. Fluctuations between 4.70-5.5V while idling. I have not observed if the V changes with RPM just yet, as this is when I shut the hood in disappointment and took a step back to post here.

Any help would be much appreciated, I know that is a lot to read, but I figured if I'm gonna post, might as well make it thorough....

Historical issues and gremlins I have brushed off in the past:
-Random loss of power, always on an uphill stretch, once causing an overheat in Oklahoma. Most times this happened the engine would eventually stall, but I could restart on the fly in neutral. This problem seemingly went away after I replaced the alternator many miles later after a failure inside the alternator was causing repeated stall-outs.
-Sometimes Eugene would randomly stall out on hard left turns, this was a very random and sparse gremlin. Yet to happen again for months.
-Prior to the main issue, Eugene's startups were getting slightly longer week-by-week to the point of having to turn-key twice for startup.
-Cruise control stopped responding to SET about 500 miles before incident.
Edit:
-Would receive a Check Transmission notice quite often on long trips.
P1744 FORD - Torque Converter Clutch System Stuck in Off Position.
Did not receive this code often, although dash would say check tranny, it would RARELY send a code.
-Received code P1270 once before in my records:
P1270 FORD - Indicates that the vehicle has been operated in a way that caused the engine or vehicle to exceed a certain calibration limit.
-Every now and then my CEL would illuminate to tell me P0316 Misfire Detected
-Sometimes on startup I will have surges where I have to really hold the brake to get the car to stop. this happened immediately after the first MAFS replacement.

Edit:
Cleaned the IAC to achieve no difference. After that I had a hunch to replace the PCM fuse, and the car ran great! Until it gave me the first original symptoms again about 30 miles later. Engine was stumbling under power. Starts up nicely, idles fine. I feel like I’m getting close here!

Other info:
149,483 miles

If I remember any other issues, I will edit.

Thank y'all very much for your time!
-Alex-
 

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Failing coil pack, plug wires, spark plugs? When, if ever, were any of these replaced? Pull coil pack and inspect it for any cracks, especially on the bottom. If any cracks, no matter how small, replace coil pack with Motorcraft or BWD (Borg Warner - Fords OEM supplier for coil packs and other ignition components). Other cheap aftermarket coil packs are JUNK. I have seen coil packs fail with WAY less than 150K miles.
 

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Discussion Starter · #3 ·
Hello,
I have come into what seem to be a major gremlin with my '07. This started after I did a hard pull accelerating on the on-ramp. (It was probably the highest I have ever had the tach up to) Next day, Eugene was stumbling under low acceleration until shift-point. I had trouble under load going uphill.

Note: The battery would be dead on startup every time since initial issue

-I did not find a fuel pump replacement anywhere in Eugene's records, and the pump did not sound too good to begin with, so I started there with a new fuel pump/assembly and in-line filter. This pepped the car back up instantly for a little drive around the block. Parked it, battery was flatlined after 20 min cooldown, jumped it, hard start, very rough idle, almost impossible to keep running. Backfiring, black smoke.

-Time for a new battery so I can run some real tests, tried to save the old one, she's dead, Jim. Same issues on startup, rough idle, backfiring, black smoke, difficult to gain Rev's.

-To begin consulting with the Oracle (Hayne's manual).

-Lets get into Eugene's wiring. (Ref. 0-21 part 7 Haynes Man)
1. I inspected the harness from MAFS back to throttle body assy. to the best of my ability without removing too many interfering parts. No issues found aside from some cracked loom shielding.
2. Checked for vacuum leaks via spraying carb cleaner around the throttle body, no response. Sprayed carb cleaner into the throttle body downstream of the MAFS, no response. All bolts are tight.
3. Insufficient fuel pressure? Sending unit was replaced, and operating perfectly. (Ref. 4-12 part 14) Checking the IAC. I ran a voltage test on the IAC, to find that the PCM was only sending .29V to IAC. Resistance of valve: 9.9 Ohms. We will revisit this issue later, as I took note and moved on.
4. Suspected issue with MAFS. I ran the engine in open loop with MAFS disconnected, ran great under throttle. Lifted front end up and got'em in gear and tried to let the computer relearn in open loop after having its brain shocked. Everything was fine until I had my assistant plug in the MAFS for an instant rough idle and stall out.. Hmmm... I had replaced the MAFS not long ago, but hey, check it anyways. Found an OL doing a resistance test on the heated wire. Replaced MAFS. Hallelujah!!! Right? No.

-Eugene started right up, idled fine, even went for a cruise around the block and brought him up to temp. Parked it, and got ready to wrap up when, uh oh. Now that he is warmed up, he does not want to stay running. Revs up just fine, but unable to hold idle without foot assistance. Took the air filter out for shits'n'giggles, and he held idle around 700 rpm, not dying but noticeably has bronchitis.
-Time to break out the multimeter again. I back-pinned the IAC to see what instructions it was receiving from PCM. Fluctuations between 4.70-5.5V while idling. I have not observed if the V changes with RPM just yet, as this is when I shut the hood in disappointment and took a step back to post here.

Any help would be much appreciated, I know that is a lot to read, but I figured if I'm gonna post, might as well make it thorough....

Historical issues and gremlins I have brushed off in the past:
-Random loss of power, always on an uphill stretch, once causing an overheat in Oklahoma. Most times this happened the engine would eventually stall, but I could restart on the fly in neutral. This problem seemingly went away after I replaced the alternator many miles later after a failure inside the alternator was causing repeated stall-outs.
-Sometimes Eugene would randomly stall out on hard left turns, this was a very random and sparse gremlin. Yet to happen again for months.
-Prior to the main issue, Eugene's startups were getting slightly longer week-by-week to the point of having to turn-key twice for startup.
-Cruise control stopped responding to SET about 500 miles before incident.
Edit:
-Would receive a Check Transmission notice quite often on long trips.
P1744 FORD - Torque Converter Clutch System Stuck in Off Position.
Did not receive this code often, although dash would say check tranny, it would RARELY send a code.
-Received code P1270 once before in my records:
P1270 FORD - Indicates that the vehicle has been operated in a way that caused the engine or vehicle to exceed a certain calibration limit.
-Every now and then my CEL would illuminate to tell me P0316 Misfire Detected

If I remember any other issues, I will edit.

Thank y'all very much for your time!
-Alex-
Failing coil pack, plug wires, spark plugs? When, if ever, were any of these replaced? Pull coil pack and inspect it for any cracks, especially on the bottom. If any cracks, no matter how small, replace coil pack with Motorcraft or BWD (Borg Warner - Fords OEM supplier for coil packs and other ignition components). Other cheap aftermarket coil packs are JUNK. I have seen coil packs fail with WAY less than 150K miles.
Replaced plugs, wires, and coil pack @ approx. 120k. All NGK products. I will pull and inspect tomorrow morning. Thank you for your time!
 

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Discussion Starter · #6 ·
So how about that draining of the battery?

I assume the battery is charged by the alternator. The battery indicator is on when you turn the ignition and goes off (and there is 14.5 V at the battery) once the engine runs, right?
I measured 14.1 V from alternator terminal to negative terminal at battery holding a 1k idle
 

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Discussion Starter · #7 ·
Compression check? See what the plugs look like? Clean the grounds? Battery cables?
Since the problem started immediately after 'blowing the cobwebs out of it' maybe you blew out more than cobwebs.....
I have had a suspicion that it might be a compression issue.. I hope it truly isn’t. I will do a compression check when I pull the intake manifold to check the plugs, injectors, and coil pack. I cleaned the ground to the PCM and block, but I haven’t yet cleaned the ground from battery to body, I will do that ASAP as well. I installed new 4 gauge cables and new battery terminals last time I was under the hood.
 

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Discussion Starter · #9 ·
Have you had any misfire codes pop up yet? I'd start by pulling the plugs and seeing how they look. Maybe a ground strap broke off or something.
We are getting somewhere! Pulled the plugs and installed Motorcraft plugs. Car is running quite well, except the CEL came up and told me I have a bad cat now.. SMH. car stumbles sometimes upon acceleration at stop signs and red lights, and occasionally on tough hills. Going to clean the cats and move forward from there on my endeavor to have this bull running perfect. Thank you for your help!
 

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Failing coil pack, plug wires, spark plugs? When, if ever, were any of these replaced? Pull coil pack and inspect it for any cracks, especially on the bottom. If any cracks, no matter how small, replace coil pack with Motorcraft or BWD (Borg Warner - Fords OEM supplier for coil packs and other ignition components). Other cheap aftermarket coil packs are JUNK. I have seen coil packs fail with WAY less than 150K miles.
Thank you, in the end, you were dead on correct. I should have taken your words more seriously from the get-go. Replacing all of my cheap components with Motorcraft, has made this bull run right again. Thank you again!

Edit
Humbled.
This edit is mostly to warn others about using NGK products in their Ford's.
LEARN FROM MY MISTAKE!

Eugene is back up and running like the bull he's supposed to be. To much embarrassment, the end-all issue was the NGK products I replaced at around 120k. Since my last update, I pulled all the plugs to do a compression check to realize most of the NGK plugs had worn to just over .100 in. Holy cow.. Replaced the NGK plugs with Motorcraft, for instant gains. Still stumbling every now and then, and it got worse. P0301 Misfire, Cyl 1&5 with over 200 misfire incidences recorded each. Did a spark test by pulling the boot just above the coil pack to inspect the spark strength. Barely sparking on both far left boots (Cyl. 1&5) comparatively to the rest. Replaced NGK coil pack and wires with Motorcraft coil pack and wires, per a few recommendations by you all. This is the end of this thread, the issue has been solved. I hope others find this thread and trials useful in fixing their own bulls. Thank you all for the support, Eugene is happier than the day I bought him!
 

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There's a YT video out there warning about fake NGK plugs (from guess where). Packaging, etc. look genuine, plugs aren't. You get what you pay for.
Plugs are one thing where the parts price vs the labor and risk of problems make it where, I will only use MC from RA. I have now 3 DOHC in my herd, and have sold 2 others. They are a bit of labor to install.
Pic of new plugs, visible bad. And another pic of a fail, new plug, new wires. Wires MC. the top of that plug is mis formed and does not fit tight in the wire end. Floppy loose while MC plugs fit tight making good electric connection. Problem with arcing, it does not misfire. Just runs horrible. Tec at local Ford garage told me it was a common problem.
-chart-
 

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