Symptoms of bad TFI module?
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Post Fiend
Joined: Nov 2001
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From: Topsfield, MA
Originally Posted by Popa Tim
How did you cut the old wires?
Since the old harness is still plugged in might you have shorted out some injector signals?
Thats my first impression.
Popa Tim
(edit)
Also, what kit is this, seems that some are Sequential rather than batch so you'll need to make sure the injector order is correct now too.
Since the old harness is still plugged in might you have shorted out some injector signals?
Thats my first impression.
Popa Tim
(edit)
Also, what kit is this, seems that some are Sequential rather than batch so you'll need to make sure the injector order is correct now too.
Someone else has mentioned that as well, I am going to make sure those wires don't short out. There does seem to be an injector firing order mixup.
I have an MSD pro-billet for a 95 351 f-150...what should I do, take the cap off, and look at the toothed wheel in there and see if they're all equidistant? Apparently they're not suppose to be, that the number one is different, right? Well what if I don't have that lined up with #1 on the dizy cap? Or is that not possible since the rotor only goes on one way...
Elder User
Joined: Sep 2004
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Pull off the cap. Look inside the dizzy bowl. The reluctor teeth hang down below there area where the distributor weights would be in an older style distributor. The teeth pass between the poles of the Hall effect sensor. This sensor is mounted to the bottom of the distributor bowl.
On the stock Ford product, for an SFI-capable distributor, the toothed ring has equal sized "teeth" and "spaces", except for one tooth. This "signature tooth" is the one tooth that is narrower than the others (and narrower than the gap between teeth). The difference should be quite noticeable. If all the teeth look the same, it is a dizzy only capable of use with a batch fire system.
On the stock Ford product, for an SFI-capable distributor, the toothed ring has equal sized "teeth" and "spaces", except for one tooth. This "signature tooth" is the one tooth that is narrower than the others (and narrower than the gap between teeth). The difference should be quite noticeable. If all the teeth look the same, it is a dizzy only capable of use with a batch fire system.
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Post Fiend
Joined: Nov 2001
Posts: 14,947
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From: Topsfield, MA
ok, I've gotcha...
I figured out what the problem was with my motor. My edelbrock intake instruction sheet, led me in the wrong direction. I was using that, to give me the reference as to where the plug wires go ontop of the dizzy. I had them on wrong, their instructions were wrong, and I fixed it. See other thread in 302/351 forum (link i gave above).
Apparently, my dizzy is ok.
I figured out what the problem was with my motor. My edelbrock intake instruction sheet, led me in the wrong direction. I was using that, to give me the reference as to where the plug wires go ontop of the dizzy. I had them on wrong, their instructions were wrong, and I fixed it. See other thread in 302/351 forum (link i gave above).
Apparently, my dizzy is ok.
Post Fiend
Joined: Oct 2003
Posts: 6,214
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From: New Jersey
Originally Posted by MustangGT221
I have an MSD pro-billet for a 95 351 f-150...what should I do, take the cap off, and look at the toothed wheel in there and see if they're all equidistant? Apparently they're not suppose to be, that the number one is different, right? Well what if I don't have that lined up with #1 on the dizy cap? Or is that not possible since the rotor only goes on one way...
Get yourself a ford 351W dizzy (beg, borrow, etc) and give it a try and see if it works correctly, magically. If it does, then you've narrowed your issue down to the MSD, and you can call MSD and see what they can sell you to upgrade your dizzy. I can't imagine they don't have seq-compatible dizzy's, as a 351W into a Mustang is a common swap.
Lead Driver
Joined: Nov 2002
Posts: 9,554
Likes: 38
From: Concord, NC
My stock batch fired distributor reluctor ring has a narrow tooth on cylinder 1. That was from '87, I'm sure the newer trucks didn't go away from that. The batch fire still needs to know where cylinder one is just as a reference. It has to be correct though, Justin got his truck running.
Elder User
Joined: Jun 2006
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Originally Posted by frederic
O2 sensor would be the next thing I'd look at, but the EEC would flag that for you in it's list of codes that it spits out. The MAP sensor isn't always captured with a code, though I'm not sure why.
Now, based on all the various opinions, I lean toward plugged cats or fouled injectors. My own analysis of what I've read, though, injectors normally foul OPEN, causing much smoke/soot, and really crappy idle. Got none of that. In fact, looking at the tail pipe, it looks TOO clean, like it's lean all the time. Never smell the exhaust, at least nothing that smells rich. Normally, clean tail pipe is tranny fluid or coolant going through engine. Umm, no tranny fluid with M5OD. Last time I topped the coolant was back in February, and not missing a drop since. OEM coolant was in it for the first 100K, and only reason I changed it then was because it was getting to be quite a nasty color. Think I added about a quart since I changed it, with another 35K on it. Still pretty green. Don't miss a drop of oil between changes. Pulled #1 plug, and to me, looks TOO clean too. Still looks brand new with about 20K on it.
My reason for leaning toward constipated cats is I know I had FPR failure at about 60K. Burned 3/4 (about 12 gallons) tank of fuel in less than 100 miles. OUCH!!. Looked like an old coal fired locomotive going down the interstate. Trying to remember, but seems my performance/driveability has been degrading since. Dealer's monkeying around with it wound up causing busted manifolds (due to EXTREME misfires at interstate speeds) which were replaced with Ford Racing shorties. Dunno why they didn't try to sell me new cat Y pipe then, but then again, by the time I got my work horse back, I think they were trying to get rid of me. Last time I went in their driveway, they were all running and hiding. The average length of the words in my vocabulary dropped significantly.
So, I think I'm gonna go try to gut the cats in stock Y-pipe and bolt it back on and see what happens. If this works, say goodbye to air pump, and hello to new true dual exhaust. (Ain't I lucky with no emissions checks in my state?). Any muffler shop here can build replacement exhaust. But, if it's got cats on it when it gets there, they gotta put 'em back on. This presents a new problem. Gotta find a small Y or H to put behind existing O2 bung and reconnect to muffler, OR move O2 to right shorty collector (bung hole already there). Stock Y being in place when I show up at Mufflers Inc. gonna get me saddled with new cats which will double cost of exhaust.
My big question here, is will reduced back pressure have negative effects? Will the flow increase to the point of making O2 sensor ineffective? Am I risking burning exhaust valves? (really bad experience with unbaffled headers on VW) Also, since the fuel lines all run down the left rail, is it better to keep the exhausts over on the right side and stick 'em both out the right (like the Lightning trucks)?
Thanks in advance to anyone with detailed suggestions/advice.
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my husband has a 90 f150 been running rough dies under acceleration & wont start again until after cooling. I had a friend pull the fuel pump & was bout to go by a new one when I found this website. So I have spent the last 2 days reading all of these forumns. I have discovered that it's not the fuel pump @ all. The TFI module can cause the issues we r having. Work when cool, then under heat malfunctions! In store tests fine because it is cool. So 2morrow i will go grab 1 out of the junk yard & try it, cuz they are expensive. I seen it fixed another ford with our problems. Will let you know if it fixes ours.
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can someone help ? My daughter has purchased a one owner 88 f-150 , with a 351 power train auto 4x4. from the original owner , who is family, and has all the service records since new . but it has set for a while just cranking and running around the yard. we have replaced both lift pumps and new switching mecanism , wire plugs oil radiator all fluids and several tanks of new non ethanol fuel belt, radiator waterpump timing cover , but when you stop or while backing out of her spot at the house it stutters and some times quits if you let it idle it some times rough and low idle then picks back up, ive also sprayed down the vac hoses wth starter fluid no change , i am a recent discharged wounded warrior and it takes me a while to repond and check the suggestions as my son has to help but i am very mechanical inclined just need help from ford experts who have more knowledge in the subject, THANKS IN ADVANCE FOR ANY OR ALL ANSWERS oh and also it only had 100,000 on it when we got it
Mountain Pass
Joined: Feb 2001
Posts: 242
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From: Washington
I know this is an old post, but I would like to know how to get the codes from my 1989 F350 7.5
The link below no longer works...
Here is a thread with the issues I am trying to figure out ford-trucks enthsiast won't allow link to be posted):
"Need TFI relocation kit for 1989 F350 7.5L"
I have replaced/relocated the TFI module, but still having serious issues.
The link below no longer works...
Here is a thread with the issues I am trying to figure out ford-trucks enthsiast won't allow link to be posted):
"Need TFI relocation kit for 1989 F350 7.5L"
I have replaced/relocated the TFI module, but still having serious issues.
TFI modules typically work, or don't work, because they get saturated with heat and
"baked dead" long before they start acting funny.
If you have a fender-mounted TFI module on a heatsink, then it won't get baked dead, but it can "wear out" and you might get some flakiness in ignition. Essentially, the only real sympton is weak or inconsistant spark, as the TFI module drives the coil as well as provide timing feedback to the EEC from the distributor's "wheel of tabs".
Regardless of location, most of the F and E series trucks have the gray TFI module, and the cars are a mix of gray and black, depending on the car. Using the wrong one doesn't prevent the vehicle from operating, just makes for weaker spark than you'd like.
Rough running doesn't necessarily mean ignition either Justin, could also be a minor vacuum leak. Remember that speed density EFI which the E and F series trucks have, rely on manifold vacuum as a primary sensor to determine how much fuel to apply, so if you've added a lumpy cam that causes oscillations in vacuum, or have a small vacuum leak, or a marginal MAP sensor (or a loose ground that the MAP is hooked to), or the ground strap between the passenger side of the engine and the firewall/fender is rotted, missing, or broken, sometimes you can have rough running situations as well.
I'd try to troubleshoot this by looking for codes first, and see if the computer picked up anything obvious. I have the full code listing on my website, and a "stolen" picture as to what to connect together to get the EEC to spit codes. Essentially jumper the two connectors with a wire, then go inside an count blinking off your check engine light, with the key in the "run" position but the engine not running.
http://www.midimonkey.com/~frederic/f350/eec-codes.html
If the computer found something useful to you, start there. If not, then I'd check vacuum while the engine is idling, to see if vacuum is fluctuating, low, or something along those lines. If you have good, consistant vacuum at idle (which you should unless you have a lumpy cam), then I'd hook a voltmeter to the MAP sensor and see what it is providing to the computer.
While an uncommon problem, my F350 crewcab eats at least one MAP sensor a year. I have no idea why, I've never been able to figure it out, as it's the only sensor that gets "whacked". But it happens often and consistant enough that I keep a spare junkyard MAP sensor in the bedbox "just in case". It never dies in my driveway, always during a 1200 mile trip. I've never heard of anyone else having such a problem, but it's at least something to look at that would in fact effect how smooth the engine runs or not.
O2 sensor would be the next thing I'd look at, but the EEC would flag that for you in it's list of codes that it spits out. The MAP sensor isn't always captured with a code, though I'm not sure why.
"baked dead" long before they start acting funny.
If you have a fender-mounted TFI module on a heatsink, then it won't get baked dead, but it can "wear out" and you might get some flakiness in ignition. Essentially, the only real sympton is weak or inconsistant spark, as the TFI module drives the coil as well as provide timing feedback to the EEC from the distributor's "wheel of tabs".
Regardless of location, most of the F and E series trucks have the gray TFI module, and the cars are a mix of gray and black, depending on the car. Using the wrong one doesn't prevent the vehicle from operating, just makes for weaker spark than you'd like.
Rough running doesn't necessarily mean ignition either Justin, could also be a minor vacuum leak. Remember that speed density EFI which the E and F series trucks have, rely on manifold vacuum as a primary sensor to determine how much fuel to apply, so if you've added a lumpy cam that causes oscillations in vacuum, or have a small vacuum leak, or a marginal MAP sensor (or a loose ground that the MAP is hooked to), or the ground strap between the passenger side of the engine and the firewall/fender is rotted, missing, or broken, sometimes you can have rough running situations as well.
I'd try to troubleshoot this by looking for codes first, and see if the computer picked up anything obvious. I have the full code listing on my website, and a "stolen" picture as to what to connect together to get the EEC to spit codes. Essentially jumper the two connectors with a wire, then go inside an count blinking off your check engine light, with the key in the "run" position but the engine not running.
http://www.midimonkey.com/~frederic/f350/eec-codes.html
If the computer found something useful to you, start there. If not, then I'd check vacuum while the engine is idling, to see if vacuum is fluctuating, low, or something along those lines. If you have good, consistant vacuum at idle (which you should unless you have a lumpy cam), then I'd hook a voltmeter to the MAP sensor and see what it is providing to the computer.
While an uncommon problem, my F350 crewcab eats at least one MAP sensor a year. I have no idea why, I've never been able to figure it out, as it's the only sensor that gets "whacked". But it happens often and consistant enough that I keep a spare junkyard MAP sensor in the bedbox "just in case". It never dies in my driveway, always during a 1200 mile trip. I've never heard of anyone else having such a problem, but it's at least something to look at that would in fact effect how smooth the engine runs or not.
O2 sensor would be the next thing I'd look at, but the EEC would flag that for you in it's list of codes that it spits out. The MAP sensor isn't always captured with a code, though I'm not sure why.
FTE Chapter Leader
Joined: May 2006
Posts: 12,277
Likes: 1,285
From: Central Mississippi
Your thread:
https://www.ford-trucks.com/forums/1...f350-7-5l.html
This is a bit wordy, but info is here:
https://www.ford-trucks.com/forums/1...an-eec-iv.html
Here's another:
http://www.troublecodes.net/ford/
And youtube:
https://www.ford-trucks.com/forums/1...f350-7-5l.html
This is a bit wordy, but info is here:
https://www.ford-trucks.com/forums/1...an-eec-iv.html
Here's another:
http://www.troublecodes.net/ford/
And youtube:
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